2.2 SYSTEM OVERVIEW 2-1 2.2.1 ECG Switch Board and Analog

2.2 SYSTEM OVERVIEW 2-1 2.2.1 ECG Switch Board and Analog
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
TABLE OF CONTENTS
1
GENERAL
1.1
1.2
1.3
1.4
INTRODUCTION
IDENTIFICATION
INQUIRES
1.4.3
1.8
1.9
2
1-1
DESCRIPTION
1.4.1
General
1.4.2
1.5
1.6
1.7
1-1
1-1
1-2
1-2
Model 78670A Defibrillator/Monitor with Annotating Recorder . . 1-3
Model 78671A Defibrillator/Monitor/Recorder
1-4
1.4.4
1.4.5
Monitor
Recorder
1-4
1-4
1.4.6
1.4.7
1.4.8
Defibrillator Output Information
Self Diagnostics
Defibrillator Charge Time
1-5
1-5
1-6
1.4.9
Paddles
MODEL 78670A/78671A OPERATING CONTROLS
OPTIONS
GENERAL INSTALLATION INFORMATION
1.7.1
Initial Inspection
1-6
1-7
1-13
1-13
1-13
1.7.2
1-13
Claims and Repackaging
PREPARING FOR OPERATION
ENVIRONMENT
1-14
1-14
1.9.1
Operating Environment
1.9.2
Storage and Shipment Environment
1.10
POWER REQUIREMENTS (MODEL 78668A POWER BASE)
1.11
INSTRUMENT GROUNDING AND POWER CORD SETS (78668A POWER BASE) . . .
1.12
MOUNTING (78668A POWER BASE)
1-14
1-14
1.13
1-17
OPTIONAL ACCESSORY CABLES
1-15
1-15
1-15
THEORY OF OPERATION
2.1
2.2
INTRODUCTION
SYSTEM OVERVIEW
2.2.1
ECG Switch
Board and Analog Board
2-1
2-1
2.2.2
Digital ECG Circuits
2-2
2.2.3
CRT Timing Circuit and Memory
2-2
2.2.4
CRT Driver Circuit
2-2
2.2.5
Heart Rate Circuit
2-2
2.2.6
2.2.7
2.2.8
Real Time Clock
Recorder Circuit
Defibrillator Control
2-2
2-2
2-3
2.2.9
Defibrillator H.V. Circuits
2-3
2.2.10
2.2.11
2.2.12
2.2.13
2.3
2-1
Low Voltage and CRT Power Supply
Battery and Battery Relay
Quick-Mount Power Base 78668A
Spare Battery Charger 78669A
2-4
2-4
2-4
2-4
DETAILED THEORY OF OPERATION
2.3.1
ECG Switch Board 78670-60215
2.3.1.1
ECG Source Switch
2-7
2-7
2-7
2.3.1.2
Protective Circuitry
2.3.2
ECG Analog Board 78670-60155
2.3.2.1
Protection Circuitry
2.3.2.2
Differential Amplifier
2.3.2.3
Right Leg Drive (RLD)
2-7
2-7
2-7
2-8
2-8
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
2.3.2.4
ECG Leads Off Indicator
2-9
2.3.2.5
2.3.2.6
Chopper Modem and Power Supply
EMI Rejection
2-10
2-10
2.3.2.7
Chopper Driver
2-11
2.3.2.8
Baseline Restore
2-11
2.3.2.9
Fixed Gain Stage
2-12
2.3.2.10
Zero Offset Potentiometer
2-12
2.3.2.11
Calibration Potentiometer
2-12
2.3.2.12
Analog Power Supply
2.3.2.13
Electromagnetic Interference Rejection
2.3.2.14
Paddle Contact (PC)
2.3.3
ECG Digital Circuit Board
2-12
2-12
2-13
2-14
2.3.3.1
2.3.3.2
50/60 Hz Notch Filter
Auto Gain Attenuator
2-14
2-14
2-14
2.3.3.3
Manual Variable Gain
2.3.3.4
Voltage to Frequency Converter (V/F)
2-15
2.3.3.5
Auto Bias
2-15
2.3.3.6
Microprocessor
2.3.4
Microprocessor Reset "Tickle" Circuit
2.3.4.1
Beeper
2.3.4.2
Electromagnetic Interference Rejection
2.3.5
Memory/Display Board 78660-60170
2-15
2-16
2-17
2-17
2-17
2.3.5.1
2.3.5.2
2.3.5.3
Functional Overview
Oscillator and Johnson Counter
1025 Counter
2-17
2-19
2-19
2.3.5.4
Delay ECG Gate (1026 count)
2-19
2.3.5.5
Address Counter
2-20
2.3.5.6
RAM Read-Write
2.3.5.7
Bidirectional Data Bus
2-20
2.3.5.8
2.3.5.9
2.3.5.10
2.3.5.11
Digital to Analog Converter (D/A)
Sample and Hold
Ramp Generator
Analog Multiplexer (MUX)
2-20
2-20
2-21
2-22
2.3.6
Deflection Board 78660-60180
2-22
2.3.6.1
Vertical Amplifier
2-22
2.3.6.2
Horizontal Amplifier
2-23
2.3.6.3
Intensity Driver
2.3.7
2-23
Clock/Heart Rate Board 78660-60260
2-24
2.3.7.1
Heart Rate Circuit
2.3.7.2
Heart Rate Digital Display
2-24
2.3.7.3
Language Option Selector
2-24
2.3.7.4
2.3.7.5
Heart Rate Alarm Switch
Clock Circuit
2-24
2-25
2.3.7.6
Voltage Reference
2-27
2.3.7.7
Clock Battery
2-27
2.3.7.8
Clock Protection
2.3.7.9
Clock Crystal
2.3.8
Recorder Control Board 78660-60200
-^
2-20 ^
2-24
2-27
. . .
2-27
2-27
2.3.8.1
2.3.8.2
ECG Monitor to Recorder Signal
ECG Memory to Recorder Signal
2-27
2-27
2.3.8.3
Recorder Movement and Stylus Heat Control
2-28
2.3.8.4
2.3.8.5
2.3.8.6
Recorder/Signal Control
ECG Signal Amplitude Limiting and Switching
Microprocessor Reset (Tickle) Circuit
2-28
2-28
2-29
2.3.8.7
Print Head Driver
2-30
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
2.3.8.8
Print Head Protective Circuit
2-31
2.3.8.9
Input/Output Lines
2-31
2.3.9
Defibrillator Control Circuit Board 78670-60195
2-32
2.3.9.1
Microprocessor
2-32
2.3.9.2
2.3.9.3
"Ticke!" Reset Circuit
LCD Drivers and Recorder Data
2-32
2-33
2.3.9.4
2.3.9.5
2.3.9.6
2.3.9.7
2.3.9.8
2.3.9.9
2.3.9.10
2.3.9.11
Analog Multiplexer and A/D Converter
I/O Expander
Relay Drivers
Charge Done Tone
Battery LED Driver
Paddle Contact Chopper
Monitoring the HV Capacitor
Charge and Discharge Cycle
2-34
2-34
2-34
2-34
2-34
2-35
2-37
2-37
Cardioversion
2-38
2.3.9.13
Software Safety Features
2.3.10
Defibrillator High Voltage Section
2.3.9.12
2-38
2-38
2.3.10.1
General
2.3.10.2
Power Circuits
2.3.11
Pulse Width Modulator
2-38
2-39
2-39
2-40
2-40
2-40
2-41
2.3.11.1
PWM Shutdown
2.3.11.2
Soft Start
2.3.12
HV Defibrillator Inverter Circuit
2.3.12.1
HV Monitor Circuit
2.3.12.2
2.3.12.3
2.3.12.4
^\
Patient Relay Circuit
Peak Current Detector Circuit
Safety Relay Circuit
2.3.12.5
5.4 V Reference/Low Battery Shutdown
2.3.13
Low Voltage Power Supply Board 78660-60110
2.3.13.1
Pulse Width Modulator (PWM) Internal Circuits
2-42
2-43
....
2-44
2-44
2-46
2-46
2.3.13.2
External
PWM Circuits
2-48
2.3.13.3
5V. Supply Voltage Regulation
2-50
2.3.13.4
2.3.13.5
2.3.13.6
CRT Supplies (+5000 and +200 volts)
+ and -15 Volt Supplies (Refer to Figure 2-62) ....
+ and -12 Volt Supplies
2-52
2-53
2-53
2.3.13.7
Noise Filtering
2-53
2.3.14
2.3.15
Service Switch
Annotation Printout
2-53
2-54
CHECKS AND ADJUSTMENTS
3.1
3.2
INTRODUCTION
3.2.2.4
Jg^\
3-1
LEVEL II PERFORMANCE, SAFETY AND MAINTENANCE CHECKS
3.2.1
Test Equipment
3.2.2
Functional Performance Testing
3.2.2.1
Energy Accuracy
3.2.2.2
Self Testing Accuracy
3.2.2.3
Defibrillator Capacitor Charge Time
Synchronizer
'.
3.2.2.5
ECG Amplifier Noise
3.2.2.6
ECG Amplifier Gain
3.2.2.7
Heart Rate Accuracy and Alarm
3.2.2.8
Paddle Contact Indicator (PCI) Test
3.2.3
Safety and Maintenance Checks
3.2.3.1
Preliminary Safety Checks
3.2.3.2
Power Cord to Chassis Ground Resistance Check
3-1
3-1
3-4
3-4
3-5
3-5
3-5
3-6
3-6
3-7
3-8
3-8
3-8
3-9
///
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
3.2.3.3
3.2.3.4
3.2.3.5
3.2.3.6
3.2.3.7
3.2.3.8
3.3
3.4
Paddle Leakage Current (Source Leakage) to Ground. . . .3-11
Paddle Leakage Current (Sink Current) with 115 Volts App 3-12
Patient Lead Leakage Current (Source Leakage) to Ground. 3-14
Leakage Current Between Patient Leads Check
3-15
Patient Lead Leakage Current (Sink Current) with 115 Vol 3-17
Battery Capacity Check
3-17
ADJUSTMENTS
3-18
3.3.1
3.3.2
Equipment Required
Related Adjustments
3-18
3-18
3.3.3
3.3.4
3.3.5
3.3.6
Adjustment Location
Paddle Contact Indicator Adjustment
Low Voltage Power Supply Adjustments
ECG Cal Adjustment
3-18
3-20
3-21
3-22
3.3.7
ECG Amplifier Baseline Offset Adjustment
3-24
3.3.8
3.3.9
CRT Display Adjustments
Real Time Clock/V REF ADJUSTMENT
3-25
3-26
3.3.10
Real Time Clock/Heart Rate Frequency Adjustment
3.3.11
3.3.12
3.3.13
3.3.14
Common Mode Rejection Notch Filter Switches
3-28
Voltage Reference, Defibrillator Charger Circuit Board . . . 3-29
Defibrillator Output Energy Calibration
3-30
High Voltage Charge Time Adjust
3-31
3-27
3.3.15
3.3.16
3.3.17
Self Test Accuracy Adjust
Recorder Pen Heat Adjust
Recorder Stylus Contact Pressure Adjustment
3-32
3-33
3-34
3.3.18
Recorder Pen Positioning
3-35
3.3.19
3.3.20
Recorder Print Head Adjustment
3-36
Setting Real Time Clock
SPECIFICATION CHECKS
3-37
3-39
3.4.1
ECG Amplifier/Heart Rate Section
3.4.1.1
Test Equipment
3.4.1.2
ECG Amplifier Gain - Manual Control
3.4.1.3
ECG Amplifier Gain - Auto Mode
3.4.1.4
Baseline Offset - ECG Lead Input
3.4.1.5
Baseline Offset - Paddles Input
3.4.1.6
ECG Amplifier Frequency Response, Leads Input
3.4.1.7
ECG Amplifier Frequency Response Check - Paddle Input .
3.4.1.8
Input Offset Tolerance (DC) - ECG Lead Input
3.4.1.9
3.4.1.10
3.4.1.11
Input Offset Tolerance (DC) - Paddle input
ECG Amplifier Noise, Leads Input
ECG Amplifier Noise, Paddles Input
3-45
3-46
3-47
3.4.1.12
ECG Calibration Check
3-48
3.4.1.13
3.4.1.14
3.4.1.15
Common Mode Rejection (CMR) Leads Source
Common Mode Rejection (CMR), Paddles Source
Heart Rate Accuracy
3-49
3-50
3-51
3.4.1.16
Heart Rate Alarm Limits
3.4.2
Recorder Section
3.4.2.1
3.4.2.2
3.4.2.3
3.4.2.4
3.4.3
Test Equipment Requirements
Recorder Frequency Response
Recorder Gain Accuracy, Linearity, and Overshoot
Recorder Chart Speed
Defibrillator Section
3.4.3.1
3.4.3.2
3.4.3.3
iv
3-39
3-39
3-40
3-41
3-42
3-42
3-43
3-43
3-44
Test Equipment
Energy Accuracy
Delivered Energy Waveform Information
3-51
3-52
3-52
3-53
. . . 3-53
3-54
3-54
3-54
3-55
3-56
/r^l
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
3.4.3.4
Self Testing Accuracy
3.4.3.5
Defibrillator Capacitor Charge Time
3.4.4 Synchronizer Section
3.4.4.1
Test Equipment
3.4.4.2 R-wave/Sync Pulse/Discharge Delay
3.4.5
Paddle Contact Indicator
3-56
3-57
3.57
3-57
3-58
3-61
3.4.5.1
Test Equipment
3-61
3.4.5.2
Paddle Contact Indicator Test
3-61
MECHANICAL DISASSEMBLY/ASSEMBLY
4.0
4.1
4.2
4.3
j^N
4.4
PRELIMINARY INSTRUCTIONS
MECHANICAL DISASSEMBLY
MECHANICAL REASSEMBLY
4-0
4-1
4-2
4.2.1
4.2.2
Replacing the Low Voltage Power Supply Board
Paddle/Cable Assembly Replacement
4-4
4-5
4.2.3
4.2.4
4.2.5
4.2.6
Replacing the Defibrillator H.V. Board
Replacing H.V. Capacitor
Safety Relay Replacement
Patient Relay Replacement
4.2.7
4.2.8
4.2.9
4.2.10
4.2.11
4.2.12
4.2.13
4.2.14
4.2.15
4.2.16
4.2.17
4.2.18
4.2.19
4.2.20
4.2.21
Circuit Board Replacement
Recorder Board Assembly Replacement
ECG Analog Board Replacement
Switchboard Replacement
CRT Replacement
Front Panel Removal
Fuse Replacement
Knob Removal
ECG Size, Recorder, Alarm and ECG Source Knobs
Knob Replacement
Energy Selection Knob
Recorder Replacement
Printhead Replacement
Printhead Adjustment
Assembly Installation
4-13
4-13
4-13
4-14
4-16
4-16
4-16
4-17
4-17
4-18
4-20
4-21
4-22
4.2.22
4.2.23
4.2.24
4.2.25
QRS Beeper Speaker Replacement
"Paddles in Place" Reed Switch Replacement
ENERGY SELECTOR Switch Replacement
Other Components Mounted on the Flex Circuit
4-22
4-23
4-24
4.94
4.2.26
4.2.27
4.2.28
SYNC/DEFIB Switch Replacement
Flex Circuit Replacement ...
Liquid Crystal Display Replacement
4.35
4_26
4-26
4.2.29
4.2.30
LCD Replacement
LED Replacement, Front Panel
4-28
4_29
4-8
4-9
4-10
4-11
4_12
4-12
RECHARGEABLE NICKEL CADMIUM BATTERY - Bl
4.3.1 General Description
4.3.2 Charge Retention
4.29
4_29
4_29
4.3.3
4.3.4
Charging
Voltage Depression (Memory)
4_30
4_30
4.3.5
4.3.6
4.3.7
What To Do About It
Cell Reversal
Battery Replacement
4.30
4_3q
4_31
4.3.8
Storage of Nickel Cadmium Batteries
RECORDER STYLUS REPLACEMENT
a 01
J^f
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
5
TROUBLESHOOTING
5.1
INTRODUCTION
5.2
BOARD LEVEL
5-1
5.2.1
System Problems
5-2
5.2.2
5.2.3
Defibrillator H.V. Problems
LCD Readout Problems
5-2
5-4
5.2.4
5.2.5
ERROR Messages on LCD
CRT Display Problems
5-5
5-6
5.2.6
Recorder Problems
5-7
5.2.7
Indicator Malfunction
5-9
5.2.8
ECG Signal Problems
5.2.9
Real Time Clock Problems
5.2.10
5.3
5-1
Control Problems
Service Mode
5-12
5.2.12
Battery Power Base Problems
5-12
COMPONENT LEVEL
ECG Monitor
5-14
5.3.2
ECG Analog Board (A3)
5-14
5.3.2.1
ECG Section
5-15
5.3.2.2
5.3.2.3
ECG Differential Amplifier Test Procedure
Bias Voltage Check Procedure on Differential Amplifier
5-16
5-16
5.3.2.4
Paddle Contact Indicator
5-17
5.3.3
Digital ECG Board (A-4)
5.3.4
Memory Board (A5)
5.3.5
Deflection Board (A6)
5.3.6
Clock/Heart Rate Board (A7)
5.3.7
Recorder Board (A8)
5.3.7.1
Annotation (78670A Only)
5-17
5-22
5-25
5-26
5-30
5-31
5.3.7.2
CRT Digits
5-34
5.3.7.3
5.3.7.4
Switch Functions
Recorder
5-36
5-37
5-39
5-39
5.3.8.2
LCD Display
5-40
5.3.8.3
Paddle Contact Indicator
5-41
Defibrillator Charger Board (A-ll)
Pulse Width Modulator (A12-U1)
5-41
5-55
REPLACEABLE PARTS AND SCHEMATIC DIAGRAMS
6.1
6.2
6.3
INTRODUCTION
REFERENCE DESIGNATIONS
ORDERING INFORMATION
6-1
6-1
6-2
ACCESSORIES
7.1
78668A Quick-Mount Power Base
7.1.1
Theory of Operation - AC Circuits
7.1.2
Regulated Voltage Circuit
7.1.3
Raw Voltage and Battery Charge Circuit
7.1.4
Low Line Voltage Circuit
7.1.4.1
Disassembly
7.1.5
Troubleshooting Power Base
7.2
VI
5-13
5.3.1
5.3.9
5.3.10
7
5-11
5-11
5.2.11
5.3.8
Defibrillator Control Board (A10)
5.3.8.1
Error Messages
6
5-10
BATTERY CHARGER 78669A
7-1
7-1
7-1
7-2
7-2
7-2
7-3
7-9
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
7.2.1
Description
7-9
7.2.2
7.2.3
Charging
Indicator Lamps
7-9
7-9
7.2.4
Battery Charger Theory of Operation
7-10
7.2.5
Current Source
7-10
7.2.6
Circuit Voltage Regulator
7-10
7.2.7
Timing Oscillator
7.2.8
Clock Gate
7-11
7.2.9
Divide By 2048 and Divide By 4096 Counters
7-11
.7-11
7.2.10
Counter Reset Gate
7-11
7.2.11
Maintenance
7-12
7.2.12
Disassembly
7-12
7.2.13
Troubleshooting Battery Charger
7-15
7.3
RECHARGEABLE NICKEL CADMIUM BATTERY - Bl
7.3.1
General Description
7.3.2
Charge Retention
7.3.3
Charging
7.3.4
Voltage Depression (Memory)
7-19
7-19
7_19
7-19
7-20
7.3.6
Cell Reversal
7-20
7.3.7
7.3.8
Battery Replacement 78660-60401
Storage of Nickel Cadmium Batteries
7-20
7-21
OPTIONS
8-1
LIST OF ILLUSTRATIONS
FIGURE
TITLE
1-1
1-2
1-3A
Front View Model 78670A/7861A Defibrillator
Defibrillator Waveform
Paddles
1-3B
1-4
1-5
1-6
1-7
Paddle Contact Indicator
Model 78670A and 78671A Controls
Accessories Storage Compartment
Non-Fade Display
Date Time Annotation
1-8
1-9
1-10
2-1
2-2
Stored and Delivered Energy Annotation
Heart Rate and Marker Annotation
Rear Panel, Model 78670A and 78671A
Model 78670A Block Diaqram
Detailed Block Diagram, Model 78670A Foldout
2-3
ECG Source Switch
PAGE
1-0
1-5
1-6
1-6
1-7
1-9
1-9
1-11
1-11
1-11
1-12
2-1
.2-6
2-7
2-8
2-8
2-9
2-9
2-4
Protective Circuitry
2-5
2-6
2-7
Differential Amplifier
Right Leg Drive Circuit
ECG Leads Off Indicator Circuit
2-8
Chopper Modem and Power Supply
2-10
2-9
Chopper Driver Circuit
2-11
2-10
Baseline Restore Circuit
2-11
2-11A Fixed Gain Stage
2-12
2-11S Paddle Contact
2-13
vii
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
2-12
2-13
2-14
via
50/60 Hz Notch Filter Circuit
Auto Gain Attenuator
Voltage to Frequency Converter
2-14
2-15
2-16
2-15 Auto Bias Circuit
2-16
2-16
2-17
2-18A
2-18B
Microprocessor Reset (Tickle) Circuit
CRT Display and Blanking Timing
Read/Write Sequence Delay Mode
Read/Write Sequence Fixed Trace Mode
2-16
2-17
2-18
2-18
2-19
2-20
Erase Bar Generator
Oscillator and Johnson Counter
2-19
2-19
2-21
1025 and 1026 Count Circuit
2-20
2-22A
2-22B
2-23
2-24
2-25
Memory to CRT Circuit Block Diagram
Memory to Recorder and Output Block Diagram
Ramp Generator
Multiplex Driver Timing
Deflection Amplifier Block Diagram
2-21
2-21
2-21
2-22
2-22
2-26
2-27
CRT Intensity Driver
CRT Blanking Circuit
2-23
2-23
2-28
Clock/Heart Rate Board Block Diagram
2-29
Clock Circuit
. 2-24
2-25
2-30
Timing Diagram
2-25
2-31
2-32
Clock Circuit Read Cycle Timing
Clock Circuit Time Set Cycle Timing
2-26
2-26
2-33
2-34
Recorder Control Circuit
Recorder ECG Amplitude Limit Circuit
2-28
2-28
2-35
2-36
2-37
Microprocessor Reset (Tickle) Circuit
Microprocessor Reset Oscillator Equivalent Circuit
Microprocessor Reset Pulses
2-29
2-29
2-29
2-38
Printhead Driver Circuit
2-30
2-39
A8-U2 Drive Signal
2-31
2-40
2-41
Printhead Protection Circuit
"Ticker Reset Circuit
2-31
2-32
2-42
2-43
2-44
2-45
LCD Timing
Charge Done Tone
Paddle Contact Chopper
HV Capacitor Monitoring Circuit
2-33
2-35
2-35
2-37
2-46
2-47
2-48
Pulse Width Modulator
PWM Shutdown
HV Defibrillator Inverter Circuit
2-39
2-40
2-41
2-49
2-50
2-51
2-52
2-53
5-54
2-55
HV Monitor Circuit,
Patient Relay Circuit
Peak Dicharge Current Detector Circuit
Safety Relay Circuit
5.4 V Reference and Low Battery Shutdown Circuit
Low Voltage Power Supply Block Diagram
Pulse Width Modulator Block Diagram
2-42
2-43
2-44
2-45
2-45
2-46
2-47
2-56
Pulse Width Modulator External Circuit
2-48
2-57
2-58
2-59
2-60
2-61
Flyback Driver Circuit
Low Battery Detector Circuit
Low Voltage Supply DC Output Circuit
Flyback Transformer CRT Supply Waveform
CRT Supply Regulator
2-49
2-50
2-51
2-52
2-52
3-0
Circuit Board Locator
3-0
3-1
3-2
Energy Accuracy Test Setup
Five Gain Stages of AUTO
3-4
3-7
TABLE OF CONTENTS
Models 78670A178671A
78670-1
r3-3
Heart Rate Accuracy and Alarm
3-7
3-4
3-5
Power Cord to Chassis Ground Resistance Check
Test Connections to Paddles
3-9
3-10
3-6
3-7A
3-7B
3-8A
3-8B
3-9A
3-9B
3-10A
3-10B
3-11
3-12A
Paddle Leakage Current to Ground
Paddle Leakage Test with 115V Applied
Paddle Leakage Test with 115V Applied
Patient Lead Leakage Current to Ground Test
Patient Lead Leakage Current to Ground Test
3-10
3-11
3-12
3-13
3-13
3-14
3-15
3-16
3-16
3-17
3-40
Leakage Current Between Patient Leads Test
Leakage Current Between Patient Leads Test
Patient Lead Leakage Current Test with 115 V Applied
Patient Lead Leakage Current Test with 115 V Applied
Test Setup for Battery Capacity Check
ECG Amplifier Gain and Frequency Response Test Setup
3-12B ECG Amplifier Gain and Frequency Response Test Setup
3-40
3-13
3-14
3-15
3-16
3-17
3-18
ECG Amplifier Baseline Offset (Leads)
ECG Amplifier Baseline Offset (Paddles)
ECG Amplifier Frequency Response Setup (Paddles)
Input Offset Tolerance (DC) Leads Test Setup
ECG Amplifier Noise, Leads Input Test Setup
ECG Amplifier Noise, Paddle Input Test Setup
3-42
3-42
3-44
3-44
3-46
3-47
3-19
Calibration Step Waveform
3-48
3-20
3-21
3-22
Common Mode Rejection Test Setup (Leads)
Common Mode Rejection Test Setup (Paddles)
Heart Rate Accuracy Test Setup
3-49
3-51
3-51
3-23
Service Mode Test Pattern, Recorder
3-53
3-24
3-25
3-26
Energy Accuracy Test Setup
R Wave/Sync Pulse/Discharge Delay Test Setup
ECG Output Waveform
3-55
3-58
3-59
3-27
R Wave
3-59
3-28
3-29
4-1
Sync Pulse Superimposed on R Wave
R Wave/Sync Pulse/Discharge Pulse Relationship
Screw Locations for Disassembly
3-60
3-60
4-1
4-2
Inside View of 78670A
4-2
4-3
Circuit Board Shield Removal (78670A)
4-3
4-4
4-5
4-6
4-7
4-8
4-9
Low Voltage Power Supply Board Removal(78671A)
Defibrillator Charger Board Removal (78671A)
H.V. Component Servicing (78671A)
Cable Housing Assembly Removal (78671A)
Paddle Cable Replacement(78671A)
Paddle Cable Replacement (78671A)
4-4
4-6
4-6
4-7
4-7
4-8
4-10
Upper Housing Circuit Board Location
4-11
4-11
4-12
4-13
Front Panel Removal
Front Panel Removal
CRT Removal
4-14
4-14
4-15
4-14
CRT Yoke Assembly
4-15
4-15
4-16
Mother Board Fuse Location A2-F1 and F2
ECG Knob Removal
4-15
4-17
4-17
4-18
4-19
4-20
Energy Select Knob Removal
Energy Select Knob Removal
Recorder Assembly Removal
Recorder Assembly
4-17
4-17
4-19
4-19
4-21
Recorder Mechanism
4-20
4-22
Detail of Printhead
4-21
IX
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
4-23
4-24
Top View of Recorder Housing and Beeper Speaker
Front Panel Mounted Components on Upper Housing
4-23
4-24
4-25
4-26
4-27
4-28
Flex Circuit Assembly (A16)
LCD Removal Sequence
LCD Removal Sequence
LCD Removal Sequence
4-25
4-27
4-27
4-27
6-1
System Block Diagram
6-2
6-3
Schematic, Mother Board A2
Schematic, ECG Analog Board A3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-14
Schematic, ECG Digital Board A4
Schematic, Memory Board A5
Schematic, Deflection Board A6
Schematic, Clock/Heart Rate Board A7
Schematic, Recorder Control Board A8
Recorder Assembly A9
Schematic, Defibrillator Control Board A10
Schematic, Defibrillator Charger Board A11
Schematic, Low Voltage Power Supply Board A12
Schematic, Flex Circuit Assembly A16
6-15
6-16
6-17
6-18
Schematic, Heart Rate Board A17
78670A Case Assembly A1
78670A Case Assembly (cont.)
Receptacle Cable Assembly
78671A Case Assembly A1
7-1
O'iic'<-X,.ount 0o\iw vise
7-2
7-3
7-4
7-5
7-6
Quick-Mount Power Base (Bottom View)
Quick-Mount Power Base Inner Circuitry
Schematic, Power Supply Board
78669A Battery Charger
Timing Diagram
7-7
Top Cover Removal
7-8
Bottom Cover Removal
7-9
7-10
7-11
7-12
7-13
Removing Heat Radiator
Battery Charger with Top Cover Removed
Battery Charger with Bottom Cover Removed
Battery Charger Circuit Board
Schematic, Battery Charger Board
8-1
78670A, Option A03 Case Assembly
/1*%
'
6-5/6
6-7/8
6-9/10
6-11/12
6-13/14
6-15/16
6-17/18
6-19/20
6-21/22
6-23/24
6-25/26
6-27/28
6-29/30
6-31/32
6-33/34
6-35/36
6-37/38
6-39/40
7-1
--•%
7-3
7-3
7-7/?
7-0
7-11
/
7-f
7-13
7-13
7-H
7-14
7-15
7-17/1'3
8-9/10
TABLE OF CONTENTS
Models 78670A178671A
78670-1
TABLES
TABLE
1-1
1-2
TITLE
Model 78670A Defibrillator/Monitor with Annotating Recorder Specs
Model 78671A Defibrillator/Monitor/Recorder Specs
1-3
Power Cable Sets
3-1
Required Test Equipment for Level II Performance,
3-2
Equipment Necessary if the Dempsey Model 431F
3-3
Safety Analyzer is not used
Adjustment Location
3-4
3-5
Test Equipment Req'd for ECG Amplifier/Heart Rate Spec Checks
Test Equipment Req' for Recorder Specification Checks
Safety and Maintenance Tests
PAGE
.
1-2
1-3
1-16
3-2
3-3
3-18
3-6
3-7
. . . 3-39
3-52
Test Equipment Req'd for Defibrillator Specification Checks . . . . 3-54
Test Equipment Req'd for Synchronizer Specification Checks
3-58
6-1
Manufacture's Code
6-3
0^\
JP^N
XI
TABLE OF CONTENTS
Models 78670A/78671A
78670-1
XII
SECTION 1- GENERAL INFORMATION
Models 78670A/78671A
78670A-1
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
1'8670A-1
MODEL 78670A DEFIBRILLATOR/MONITOR WITH ANNOTATING RECORDER,
PADDLE CONTACT INDICATOR AND INTERCHANGEABLE PADDLE CONNECTOR
MODEL 78671A DEFIBRILLATOR/MONITOR WITH RECORDER
Figure 1-1. Model 78670A Defibrillator/Monitor with Annotating Recorder
and Model 78671A Defibrillator/Monitor with Recorder
1-0
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
78670A-1
SECTION I
GENERAL INFORMATION
1.1
INTRODUCTION
This manual contains service information for the
Model 78670A and the Model 78671A
Defibrillator/Monitors. This manual also contains complete theory of operation,
mechanical disassembly, circuit board removal and replacement procedures, and
component level troubleshooting for both instruments. Operating instructions and
installation information are covered in
the Model 78670A Operating Guide,
78670-91998 and in the Model 78671A Operating Guide, 78671-91998.
1.2
IDENTIFICATION
This manual applies to all Model 78670A and 78671A Defibrillator/Monitors having
the same or lower serial number prefix as that shown on the title page. The serial
number prefix digits are the first four of the ten-digit instrument serial number
(XXXXA00000), and identifies the latest modification of the instrument. The letter
separating the prefix and the serial number designates the country in which this
instrument was manufactured (A = USA; C = Canada; G = Germany; J = Japan; U =
United Kingdom).
The
serial
number
of
the
78670A
Defibrillator/Monitor,
78671A
Defibrillator/Monitor, and the 78669A Spare Battery Charger is indicated on the
plate which is attached to the bottom cover, near the center of the instrument.
The serial number for the 78668A Quick-Mount Power Base is located on the rear of
the instrument next to the AC power receptacle.
Important information for correcting errors, and for adapting the contents of this
manual to cover improvements that occur after the printing of the manual is
provided in a blue Manual Changes Supplement inserted under the front cover of the
manual. These supplements are keyed to the manual print date and part number, both
of which appear on the title page, and are revised as often as necessary to keep
the manual current and accurate. The Errata Section of a Manual Change sheet
contains corrections for errors
within the manual.
On the title page of this manual, preceding the manual part number, is a microfiche
number. This part number can be used to order 6.5 x 15.2 cm (4x6 inch) microfiche
transparencies of this manual. Each microfiche contains up to 60 photo duplicates
of the manual pages. The microfiche package also includes the latest manual change
as well as all pertinent Service Notes.
1.3
INQUIRES
Refer any questions or comments regarding this manual to the nearest Hewlett
Packard Sales/Service Office. Always identify the instrument by both model number
and complete 10-digit serial number in all correspondence. See the rear of this
manual for a worldwide listing of the Hewlett Packard Sales/Service Offices.
/-/
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
78670A-3
1.4
DESCRIPTION
1.4.1
General
With the exception of the annotating printhead on the recorder, the paddle contact
indicator and interchangeable paddle connector, the 78670A and the 78671A are the
same. The printhead, paddle contact indicator, paddle connector,and associated
functions and controls are deleted in the 78671A Defibrillator/Monitor.
DEFIBRILLATOR
Charge
MONITOR
Waveform: Critically damped sinusoidal.
Output Energy (Delivered):
5, 10,
20, 30, 50, 70, 100, 150, 200 300
Inputs:
ECG from paddles or 3-lead
patient cable. Lead I, II, III selectable in
LEADS position. LEADS or PADDLES
indicator lights to show selected source.
and 360 joules.
Lead
Charge Control: Push-button on apex
Fault:
Common
Charge Time:
360 joules.
Less than 10 seconds to
delivered into 50 ohms load and self test
hours for fully
Capacity:
Fifty (50) full energy
discharges or 2.5 hours of monitoring
or 1.5 hours combined monitoring and
recording.
Mode Rejection:
112 dB
Charge Indicator:
Light is on when
battery is charging; flashes when battery
is low.
with 5K ohm imbalance with respect to
STANDARD ACCESSORIES
non-isolated ground.
Delivered Energy Display:
Liquid
Crystal Display shows energy that will be
16
INOP indicator flashes
if patient lead becomes disconnected.
paddle.
Time:
depleted battery.
Display Size & Type: 4.5 cm x 9 cm for
78668A
Quick
Mount
Power
Base
3.75 seconds of ECG data on screen;
Redux® Paste, 1 oz.. Part number
non-fade, fixed trace.
651-1029
Patient Isolation: Twelve (12) megohms
ECG Cable, Part number 14489B
or greater at input connector.
Electrode
Lead Set, part number
14151 A. Disposable Electrodes, part
energy.
Armed Indicators:
Charge done tone,
light and digital display.
Safety
to 50
Interlock:
joules with
Output
internal
limited
paddles
Sweep Speed:
25 mm/sec nominal.
number 14445A.
Frequency Response:
0.5 to 40 Hz
connected.
Heart Rate
Paddle
Contact
Indicator:
3-color
LED bar graph array on sternum paddle
indicates quality of defibrillator paddle
contact before discharge.
Paddles: Standard paddles are Anterior/
Anterior, adult and pediatric. Adult
electrodes twist off to expose pediatric
electrodes.
Full
range
of
Display:
Digital readout
from 20 to 240 BPM.
ECG Output: 1V, Nominal.
off with each detected R-wave.
Marker
pulse on monitor indicates defibrillator
discharge point. Discharge occurs within
30 ms. of marker pulse.
Recorder Modes: Delayed by 4 seconds
(Real Time available).
cm
Tool,
part
number
Part
Number
Manual:
Instruction
Card:
OPTIONAL ACCESSORIES
ECG
Output
Cable,
Part
number
number
14482A.
0.5 to 40 Hz
Cable,
Part
BATTERIES
Type:
2.0 A/hr rechargeable nickel-
cadmium.
78669A Spare Battery Charger
NOTE:
Weight: 12.7 kg (28 pounds).
ORDERING INFORMATION
OPTIONS
number
14990B
and
adult
Options C03, C04, C05 and C06
are not available with option A03.
L01
French Labels
L02
German Labels
Delete interchangeable paddle
electrode (8.1 cm) set,
L03
Dutch Labels
connector.
number 14993 A.
Add Pediatric Internal
N01
CSA
N02
VDE/IEC Configuration
Paddles; includes handle set,
part
number 14990B
and
Z01
C01
Add 78669A Spare
Charger.
C02
Delete 78668A Quick- Mount
Battery
C05
part
Z05
50 Hz Operation
100 volt Operation
230 volt Operation
900
UK Power Cord
Internal
Paddles
901
Australian Power Cord
part
number
902
European Power Cord
906
Swiss Power Cord
Power Base.
pediatric electrodes (5.1 cm)
Add Adult/Pedi Anterior/
set, part number 14992 A.
Add
Posterior Paddles 14412D.
Add Adult Internal Paddles;
includes handle set, part
C06
(3.4
Infant
cm)
14416A
Z02
Table 1-1. Model 78670A Defibrillator/Monitor/Annotating Recorder Specifications.
1-2
Part
Number 5952-6866
Sync
31.1
W x 47 cm L (9" x 12.25" x 18.50").
C04
Adjustment
78660-27800.
8120-3164
Frequency Response:
x
number
10 characters/sec nominal.
SIZE and WEIGHT
H
part
9280-0980.
Operating
SYNC indicator flashes
NEMA-Female
ft)
78670-91998
Paper Size: 50 mm x 30 m (100 ft) with
40 mm offset grid.
C03
(8
Operating
RECORDER
internal
Synchronizer:
A03
Male
2.4 m
Recorder Paper, spare roll, part number
Calibration:
Momentary pushbutton
switch simulates 1 mV signal to ECG
amplifier.
Annotation:
22.9 cm
Cable,
CEE22,
8120-3493-
paddles available.
Dimensions:
Power
SECTION I - GENERAL INFORMA TION
Models 78670AJ78671A
78670A-3
DEFIBRILLATOR
Waveform: Critically damped sinusoidal.
Output Energy (delivered): 5,10, 20, 30,
50, 70,100,150, 200,300 & 360 joules.
Charge Control:Push-button on apex
paddle.
Common Mode Rejection: 112 dB with
5K ohm imbalance with respect to non
isolated ground.
is low.
Display Size & Type: 4.5 cm x 9 cm for
STANDARD ACCESSORIES
3.75 seconds of ECG data on screen;
78668A Quick Mount Power Base
non-fade, fixed trace.
Redux® Paste, 1 oz.. Part number
Patient Isolation: Twelve (12) megohms
Charge Time:
Less than 10 seconds to
360 joules.
or greater at input connector.
Sweep Speed:
Frequency Response:
delivered into 50 ohms load and self test
Heart Rate
energy.
readout from 20 to 240 BMP.
Charge done tone,
light and digital display.
Paddles: Standard paddles are Anterior/
Anterior, adult and pediatric.
Adult
electrodes twist off to expose pediatric
0.5 to 40 Hz.
Display (Optional): Digital
SYNC indicator flashes
off with each detected R-wave.
ECG Output: 1V, nominal
Calibration:
Momentary push-button
switch simulates 1 mV signal to ECG
amplifier.
Part
number
Disposable
Electrodes,
Part
number
Power
Cable,
Male
CEE22,
2.4 m
(8 ft)
part number
Recorder Paper, spare roll. Part number
Adjustment
Tool,
78671-91998
Operating
Operating
Type:
NEMA-Female
8120-1992.
Recorder Modes: Delayed by 4 seconds
(Real Time available).
Frequency Response:
14489B.
Set,
78660-27800.
0.5 to 40 Hz.
Part
Manual:
Part
Instruction
Card:
number
number
Part
number 5952-6868
OPTIONAL ACCESSORIES
22.9 cm H x 31.1 cm W x
47 cm L (9" x 12.25" x 18.50").
Lead
number
14151A.
Paper Size: 50 mm x 30 m (100 ft) with
40 mm grid.
BATTERIES
Dimensions:
Electrode
Part
9280-0980.
RECORDER (Optional)
Marker
pulse on monitor indicates defibrillator
discharge point. Discharge occurs within
30 ms. of marker pulse.
Cable,
14445a.
electrodes.
Synchronizer:
651-1029
ECG
25 mm/sec nominal.
Delivered Energy Display:
Liquid
Crystal Display shows energy that will be
Armed Indicators:
Charge Indicator:
Light is on when
battery is charging; flashes when battery
2.0 A/hr rechargeable nickel-
cadmium.
ECG
Output
Cable,
Part
number
number
14482A.
8120-3493.
Weight: 12.7 kg (28 pounds)
Charge
16
hours for
fully
Sync
Cable,
Part
78669A Spare Battery Charger
Inputs:
ECG from paddles or 3-lead
patient cable, Lead I, II, III selectable in
LEADS position. LEADS or PADDLES
indicator lights to show selected source.
Lead Fault:
patient
Time:
depleted battery.
MONITOR
lead
Capacity:
Fifty (50) full energy
discharges or 2.5 hours of monitoring or
1.5 hours combined
recording.
monitoring
and
I NOP indicator flashes if
becomes
disconnected.
ORDERING INFORMATION
OPTIONS
A01
Delete Recorder
L01
French Labels
Z02
A02
Delete Recorder & Heart Rate
L02
German Labels
Z05
C01
Add 78669A Spare Battery
L03
Dutch Labels
900
UK Power Cord
Charger
N01
CSA
901
Australian Power Cord
C02
100 volt Operation
230 volt Operation
Delete 78668A Quick-Mount
N02
VDE/IEC Configuration
902
European Power Cord
Power Base
Z01
50 Hz Operation
906
Swiss Power Cord
Table 1-2. Model 78671A Defibrillator/Monitor Specifications.
1.4.2
Model 78670A Defibrillator/Monitor with Annotating Recorder
The 78670A is a critically damped sinusiodal waveform defibrillator (see figure
1-2) combined with a non-fade ECG monitor and annotating strip chart recorder.
Energy
is selectable
to 360 joules
(delivered into
a 50 ohm load) in
discrete steps, (400 joules replaces 360 joules with option A01).
eleven
The ECG Monitor displays HEART RATE, and ECG obtained through the paddles or
through a three-lead patient cable.
HEART RATE ALARMS are preset at 30 and 150
1-3
SECTION I - GENERAL INFORMA LION
Models 78670A/7867IA
786 70A-1
BPM. Size of the ECG waveform
adjusted if desired.
is automatically
controlled or
The recorder automatically annotates DATE/TIME, HEART RATE,
DELIVERED ENERGY, PEAK CURRENT and PATIENT IMPEDANCE during
can be
manually
SELECTED ENERGY,
a procedure.
The 73670A operates from a rechargeable 2.0 ampere-hour nickel-cadmium battery
which provides fifty 360 joule discharges, or more than 2.5 hours of continuous
monitoring or 1.5 hours of combined monitoring and recording.
A Model 78668A
(Quick-Mount Power
Base) is provided
as a standard
accessory and allows
AC line
power
ope
operation
of the Defibrillator/Monitor v/hile simultaneously charging its
battery. During battery operation, a BATTERY LOW indicator flashes when a low
battery condition exists.
Mounting the 78668A Quick-Mount Power Base to the top of a cart or vertically on a
wall provides a secure mounting for the instrument as well as a quick release for
emergency portable use.
An accessory storage compartment provides convenient storage for patient leads,
electrodes and Redux paste. The compact, lightweight package design, along with
battery operation, permits its use in portable applications.
1.4.3
Model 78671A Defibrillator/Monitor/Recorder
The 78671A Defibrillator/Monitor combines a DC defibrillator, non-fade ECG monitor
and recorder. The defibrillator recorder and monitor sections are essentially the
same as the 78670A described in Section 1.4.2 with the following exceptions: no
paddle contact indicator on the sternum paddle, no annotation on the recorder, and
non-interchangeable paddles.
1.4.4
Monitor
Fixed or moving ECG waveforms are displayed on a 4.5 x 9 cm display area. The
monitor is internally programmed to display either a fixed or moving trace with
internal programming switch S2, mounted on the memory board (78660-60 170). Fixed
trace display is comparable to a conventional oscilloscope where new information
appears to be written from left to right across the screen by repet itive sweep,
The oldest information is erased by a moving erase bar before new in formation is
written in its place. The moving trace mode provides a display simila r to that of
a strip chart recorder. New information is written in at the right edge of the
screen and moves across from right to left. The oldest information dis appears from
view at the left edge of the screen.
Sweep speed is 25 mm/sec; dis play time is
approx 3.75 seconds.
1.4.5
Recorder
Real time or 4 second delayed ECG waveforms are printed on the recorder paper. The
recorder is internally programmed to print either a real time or 4 second delayed
trace with
internal programming switch SI,
mounted on the
memory board
(78660-60170).
1-4
SECTION I - GENERAL INFORMA TION
Models 78670A178671A
78670A-l
1.4.6
Defibrillator Output Information
The defibrillator stores sufficient energy to discharge 360 joules into a fifty ohm
impedance. However, the actual energy delivered into a patient is a function of
the total impedance to the defibrillator charge. As a practical matter, the
operator controls the largest portion of this impedance by the quality of the skin
preparation. If sufficient electrolyte is applied,and paddle pressure of 20-25
pounds is used, then an impedance of approximately 50 ohms would be expected and a
near normal discharge would occur.
The output waveforms shown in Figure 1-2 indicate that with decreased impedance,
higher peak current is obtained. Recent clinical evidence indicates that the peak
current
value
must
reach
a certain
threshold
for
defibrillation
and
should
therefore be optimized for any particular energy setting.
The primary method
available to the operator for accomplishing this is through proper paddle
preparation techniques. As an aid to the operator,, the '78670A provides a paddle
contact indicator (on sternum paddle) that helps achieve best paddle contact,
before discharge, optimizing current delivered to the patient.
100 i-
360 JOULES
-20 L-
Figure 1-2. Defibrillator Waveform
1.4.7
Self Diagnostics
The 78670A and 78671A Defibrillator/Monitors use microprocessor technology to
control and monitor system operation.
This advanced design enables the unit to
perform a self-diagnostic routine.
1-5
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
78670A-1
Each time the Defibrillator/Monitor is turned ON, a self check is performed on the
control section.
If all is O.K., the DELIVERED ENERGY display will alternately
flash "HP" and "888". If a problem exists, the DELIVERED ENERGY display will flash
an ERROR CODE such as: "PI", "P2", "P3", or "P5". If an ERROR CODE flashes on the
DELIVERED ENERGY display refer to Section V for troubleshooting information.
1.4.8
Defibrillator Charge Time
Charge time
to 360
battery or rated
fully charged
joules (delivered): less
mains voltage with 78668A
battery (after
than 10
seconds with
Power Base; less than
15 maximum energy
discharges) or
fully charged
11 seconds with
90% of
the rated
The 78670A and 78671A paddle set is equipped with pediatric electrodes
twist-off adult electrodes. If pediatric paddles are required, remove
under the
the adult
mains voltage with 78668A Power Base.
1.4.9
Paddles
electrodes as follows:
Press
down on
the adapter
locking lever
and rotate
the adult
electrodes in
counterclockwise direction.
Figure 1-3A. Paddles
To replace the adult electrodes, simply
reverse the above procedure.
The 78670A incorporates a paddle
contact indicator on the sternum paddle.
A 3-color (red, yellow, green) LED bar
graph array helps operator achieve best
paddle contact, optimizing current
delivered to patient.
Figure 1-3B. Paddle Contact Indicator.
1-6
a
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
786 70A-1
Figure 1-4. Model 78670A and 78671A Controls.
1.5
1.
MODEL 78670A/78671A OPERATING CONTROLS
ENERGY SELECT
The ENERGY
SELECT control turns
the Defibrillator/Monitor ON
and OFF as
well
as
selecting delivered energy in eleven discrete steps. Switch positions are OFF,
5, 10, 20, 30, 50, 70, 100, 150, 200, 300 and 360 joules (watt-seconds).
2.
CHARGE BUTTON
Press and release the
CHARGE button to charge the defibrillator.
When the button
is pressed, the defibrillator charges in approximately 10 seconds to the energy
selected by the ENERGY SELECT control. The ENERGY SELECT must be set to the
desired level before pressing CHARGE button. If you wish to change the energy
level AFTER the defibrillator is charged, simply reset ENERGY SELECT control.
Defibrillator will charge to the new level.
1-7
SECTION I - GENERAL INFORMA TION
Models 78670A178671A
78670A-l
/*%
3.
DELIVERED ENERGY DISPLAY
The DELIVERED ENERGY readout indicates the amount of energy which will be delivered
into a 50 ohm load when the defibrillator is discharged.
The liquid crystal,
digital display permits easy viewing in almost any ambient light condition.
4.
PADDLE CONTACT INDICATOR
The PADDLE CONTACT indicator on the sternum paddle indicates the best paddle
contact, before discharge.
This helps the user optimize current delivered to the
patient. When the paddles are applied to the patient, the LED changes from RED to
YELLOW to GREEN as patient impedance decreases - indicating proper paddle pressure
and that sufficient electrolyte is applied.
5.
CHARGE DONE INDICATOR
The CHARGE DONE indicator lights when the defibrillator reaches selected energy
after the charge button is pressed and released. In addition, a CHARGE DONE TONE
indicates when the defibrillator is armed and ready for discharge.
6.
SYNC/DEFIB SWITCH
The SYNC/DEFIB switch selects either the instant defibrillation (DEFIB) or
synchronous (SYNC) mode of operation.
In the DEFIB mode, the defibrillator
discharges as soon as both of the discharge buttons on the paddles are pressed. In
the SYNC mode, the defibrillator will discharge at the first point on the ECG
waveform indicated by
the marker pulse —
after both discharge buttons
have been
pressed.
The defibrillator automatically
is turned on.
(SYNC position).
by moving the
sets itself to the DEFIB mode
when the instrument
For synchronized operation, move the switch momentarily to the left
The defibrillator can be reset for instant discharge at any time
switch
momentarily back
to the DEFIB
position
or turning this
instrument off and on.
Note: For synchronized operation, the ECG SOURCE selector must be in the LEADS
position. If the ECG SOURCE selector is in the PADDLES position, the unit will NOT
go into the sync mode.
7.
SYNC INDICATOR
The SYNC
indicator flashes off with
each detected R-wave during the synchronized
mode of operation.
8.
ECG SOURCE SELECTOR
The ECG SOURCE selector selects the source of the incoming ECG signal: 3-lead ECG
cable (LEADS) or ECG pick up from paddles (PADDLES). LEADS I, II and III may be
selected in the LEADS position. In addition, in the LEADS position, the indicator
will flash should an electrode become disconnected, indicating an INOPerative
condition.
1-8
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
786 70A-1
9.
ACCESSORIES STORAGE COMPARTMENT
The accessories
storage compartment provides a convenient place to
leads, electrodes and Redux
MONITOR
INTENSITY
and
paste.
R-WAVE
store patient
In addition, the ECG (LEADS) input conector,
BEEPER
VOLUME
controls
are
located
in
this
compartment.
Figure 1-5. Accessories Storage Compartment.
The R-wave beeper aids in audible detection of some arrhythmias; volume is adjusted
using the VOLUME control. When heart rate alarms are enabled and the limits are
exceeded, the beeper provides an audible warning.
Turn the ALARM switch to OFF to
silence the alarm.
10.
NON-FADE MONITOR AND DIGITAL HEART RATE DISPLAY
The non-fade
oscilloscope is internally
programmed to
display either a
fixed or
moving ECG waveform and digital heart rate. Fixed-trace display is comparable to a
conventional oscilloscope where new information is written across the screen by a
repetitive sweep from left to right. The oldest information appears to be erased
by a moving "erase" bar before new information is written in its place.
The moving trace mode provides a display similar to that of a strip chart recorder.
New information appears at
screen.
the right
edge of the display
and moves
across the
The oldest information disappears off the left edge of the screen.
Sweep speed is 25 mm/second and display time is 3.75 seconds.
DIGITAL HEART RATE is displayed on the monitor
screen in beats per minute as shown
below.
Figure 1-6. Non-Fade Display:
1-9
SECTION I - GENERAL INFORMA TION
Models 78670A178671A
78670A-l
11.
ECG SIZE CONTROL
The ECG SIZE control (combined with 1 mV Cal button) adjusts and maintains the size
of the ECG waveform displayed on the monitor. Turn clockwise to the AUTO position
and the height of the waveform is automatically maintained between 0.8 and 1.6 cm
when in the DEFIB or instant mode. When the defibrillator is operated in the
synchronized or SYNC mode, the AUTO setting is locked out.
When the ECG SIZE control is pressed, the monitor generates a simulated 1 mV signal
for calibrating the display.
The calibration signal will also appear on the
recorder, if it is running (delayed by four seconds in the delayed mode).
12.
RECORDER CONTROL/PUSH FOR 8 SECOND RUN BUTTON
The RECORDER control has three positions —
STANDBY, RUN and PUSH FOR 8-SEC RUN.
With the RECORDER control in the STANDBY position, the recorder turns on
automatically when the ALARM switch is in the ON position and heart rate alarm
limits (30 and 150 BPM) are exceeded, and/or when the
is pressed.
When initiated by alarm violation, the
defibrillator CHARGE button
recorder run lasts for 16
seconds. When initiated by pressing the CHARGE button, the recorder runs lasts for
12 seconds after discharge.
With the RECORDER control in the RUN position, the recorder runs continuously until
the operator returns the RECORDER control to the STANDBY position or the low paper
switch activates.
CAUTION: To prevent possible printhead damage, the recorder should not be operated
without paper installed. A new paper roll provides approximately 20 minutes of
recording time and a red warning strip appears approximately 30 feet from the end
of the paper roll.
PUSH FOR 8-SEC RUN turns the recorder on for a timed 8 second run. Multiple taps
of the control result in consecutive 8-second runs up to a maximum of 60 seconds.
Any recorder run can be terminated by moving the RECORDER control switch to the RUN
position and back to STANDBY.
13.
ANNOTATING RECORDER (78670A only)
The annotating recorder uses 50 mm, thermal paper (HP Part Number 9270-0980) with a
40 mm offset grid to allow printing along the top edge.
Stylus heat and baseline
position are screwdriver adjustments from the front of the recorder enclosure (they
are preset and should not need adjustment).
Each time the recorder runs, DATE/TIME and patient HEART RATE are alternately
annotated at 5 second intervals as shown in Figure 1-7.
When the recorder run is initiated by pressing the CHARGE button, SELECTED ENERGY
is annotated. When the DISCHARGE buttons are pressed, actual DELIVERED ENERGY,
PEAK CURRENT and PATIENT IMPEDANCE are annotated (if the patient impedance is
measured to be less than 200 ohms).
A sample strip is shown in Figure 1-8.
Note: At a 5 Joule setting, no delivered energy information will be printed.
1-10
^
/
SECTION I - GENERAL INFORMA TION
Models 786 70A/786 71A
78670A-1
MONTH
HEART RATE
DA\E
_
H0UR & M|NUTES
/
SECONDS
23 :|:EP 1513:f0
KM HEWLETT » PACKARD
Figure /-7
DELIVERED 110J 19A 12 J OHf-fS 23 SEP 1531:50
J^s
Figure 1-8
14.
ALARM SWITCH/PUSH TO MARK BUTTON
The ALARM switch has three positions -- ON, OFF and PUSH TO MARK (78670A only).
With
the ALARM
switch
in the ON
position,
an
16-second recorder run are initiated when patient
audible warning
and
automatic
heart rate remains lower than 30
BPM or higher than 150 BPM for more than 4 seconds.
The alarm limits are not adjustable. Alarm reset occurs automatically if the heart
rate returns to the 30 to 150 BPM range.
With the ALARM switch in the OFF position, the alarm circuitry is disabled.
ARROW ( \ ) and the TIME on the recorder
PUSH TO MARK (on78670A only) gives a down
paper.
This function
is useful in recording the occurrence
of significant events
MA kRKER
X
EP
^
t
t
,-
15
r
HF:
-
i
4
~*
*K * * V
,7I 1
•i-
1
|
1
J
\
I
J
A
jl
jl
Wi—
2~-5 S EP
l£l 2 •?.?
;
,
i
•
1
1
i
i
Jgs^N
i
$
rl
i,ti
u
,t# ii.t
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*.
t
-
-
r
.
• !"'
.1
II
ill'
:
tt
it.,
t
,1
.1
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1
Figure 1-9
1-11
SECTION I- GENERAL INFORMATION
Models 78670A/78671A
78670A-1
during the episode.
the
clinician
to
An arrow is annotated each time the switch is pressed enabling
develop
codes
for
common
events
such
as
drug
infusion,
administration of oxygen, etc.
15.
BATTERY STATUS INDICATOR
The battery status indicator flashes when a low battery condition exists and lights
steady when the defibrillator is in the Quick-Mount Power Base with the power base
connected to AC power and the battery is installed. When the light is on steady,
it indicates the battery is charging. If the indicator begins flashing, either
replace the battery with a fully charged one from the spare battery charger or
place the 78670A in the power base. The Defibrillator/Monitor is available for use
whenever it is in the power base (and the power base is plugged in) regardless of
battery charge status.
16.
Battery charge time is 16 hours.
PADDLE CONNECTOR
Provides two-wire differential ECG signal
input to Defibrillator/Monitor and
provides power output to the paddles.
BATTERY
EJECTION/LOCKING
REAR PANEL
LEVER
/
A
B
C
Figure 1-10. Rear Panel, Model 78670A & 78671A Defibrillator.
A.
IV ECG OUT
The rear panel mounted
IV ECG OUT mini-phone plug connector provides a high level
(IV) ECG signal from the monitor.
B.
BATTERY PACK
The battery pack ejection/locking lever ejects the battery pack when moved to the
left and locks the battery pack in place when moved to the right. (Refer to
Section Four for Battery Pack Replacement).
C.
CHARGER INPUT
The CHARGER INPUT connects to the output plug of the 78668A Quick-Mount Power Base
to provide operation from AC power while the internal battery pack is recharging.
1-12
*>
SECTION I - GENERAL INFORMA TION
Models 78670Aj78671A
78670A-1
1.6
OPTIONS
Options available for
use with both the 78670A and
78671A Defibrillator/ Monitors
are listed in Tables 1-1 and 1-2.
1.7
GENERAL INSTALLATION INFORMATION
1.7.1
Initial Inspection
1.7.1.1
As soon
Mechanical Inspection
as the
shipping container
is opened,
check the
instrument for
visible
damage, such as broken controls or connectors, and dents or scratches on the panel
surface. If damage is found, refer to Paragraph 1.8.2 for the recommended claim
procedure and repacking information. If the shipping carton is not damaged, check
the cushioning material and note any signs of severe stress as an indication of
rough handling in transit.
This may be necessary to support claims for hidden
damage which may become apparent only during subsequent testing. Retain the
packaging material for possible future use.
1.7.1.2
Electrical Inspection
Check the electrical performance of the instrument as soon as possible after
receipt, using the recommended performance checks in Section 6 of the Operating
Manual.
1.7.2
Claims and Repackaging
1.7.2.1
Claims for Damage
If physical
operational
damage is evident or if the
requirements when received,
defibrillator does not meet specified
notify the carrier and the nearest
Hewlett-Packard Sales/Service Office at once.
1.7.2.2
Original Packaging
Containers and materials used to ship your 78670A and 78671A are specifically
designed for the instrument and not readily available through local Hewlett-Packard
offices, therefore, RETAIN THE ORIGINAL MATERIALS FOR FUTURE USE.
If the
instrument is being returned to Hewlett-Packard for servicing, attach a tag
indicating the type of service required, return address, model number and full
serial number.
Also, mark the container FRAGILE to ensure careful handling. In
any correspondence, refer to the instrument by model number and full serial number.
1.7.2.3
Follow
Other Packaging
these general
instructions when
repackaging
with commercially
available
materials:
#*N
Wrap the instrument in heavy paper or plastic. If shipping to a Hewlett- Packard
office or service center, attach a tag indicating the type of service required,
return address, model number and full serial number.
1-13
SECTION I- GENERAL INFORMATION
Models 78670A/78671A
78670A-1
Use a strong shipping
material is adequate.
container.
A double-wall carton
made of
350 pound
test
Use enough shock absorbing material (3 or 4 inch layer) around all sides of the
instrument to provide firm cushioning and to prevent movement inside the container.
Protect the control panel with cardboard.
Seal the shipping container securely.
Mark the shipping container FRAGILE to ensure careful handling.
1.8
Preparing for Operation
Refer
to
Section
6
of
the
Operating
Manual
for
checkout
and
installation
procedures.
1.9
ENVIRONMENT
1.9.1
Operating Environment
The location of your Defibrillator/Monitor
should be reasonably free from
vibration, dust, corrosive or explosive vapors or gases, extreme temperature and
excessive humidity. The operating environment for the 78670A and 78671A including
all options is:
Temperature: -20 degrees C through 55 degrees C (-4 degrees F through
131 degrees F)
Relative Humidity: 5% through 95%
Altitude: 4,500 m (15,000 ft) max
Note: Instrument meets all specifications from zero degrees C to 55 degrees C
(32 degrees through 131 degrees F).
For maximum battery life the instrument
should not be used on the 78668A Power Base below zero degrees C (32 degrees
F).
WARNING: DO NOT USE THE DEFIBRILLATOR IN A FLAMMABLE ATMOSPHERE (i.e. OXYGEN TENTS
OR WHERE CONCENTRATIONS OF FLAMMABLE ANESTHETICS MAY OCCUR). AVOID USING PORTABLE
OR EMERGENCY VEHICLE-MOUNTED DEFIBRILLATORS AROUND AUTO WRECKS.
SPILLED GASOLINE
AND PUDDLES OF WATER PRESENT EXTREMELY DANGEROUS EXPLOSION AND SHOCK HAZARDS.
1.9.2
Storage and Shipment Environment
The storage and shipping environment for the 78670A and 78671A are:
Temperature: -40 degrees C through 65 deqrees C (-40 degrees through 149 degrees F)
Altitude: 9,000 m (30,000 ft) max
Relative humidity: 5% through 95%
1-14
SECTION I - GENERAL INFORMA TION
Models 78670A/78671A
78670A-1
1.10
POWER REQUIREMENTS (MODEL 78668A POWER BASE)
The Model 78668A Quick-Mount Power Base allows AC operation of both models. The
instruments will operate from a line voltage of from 100 to 130 Vac (115 Vac
nominal) at 50-60 Hz with the 78668A rear panel line selector in the 115 position.
In addition, operation from a line voltage of 200 to 250 Vac (230 Vac nominal) at
50-60 Hz is possible with the line selector in the 230 position.
1.11
INSTRUMENT GROUNDING AND POWER CORD SETS (78668A POWER BASE)
To protect hospital personnel and the patient, the Power Base must be properly
grounded. Accordingly, the Power Base is equipped with a detachable 3-wire power
cable which grounds the instrument to the power line ground when plugged into an
appropriate 3-wire receptacle.
Available power
sets, USA and non-USA are
identified and described in Table 1-3, Power Cable Sets.
WARNING:
OUTLET.
FOR PROPER
GROUNDING, THE
POWER RECEPTACLE
A HOSPITAL GRADE OUTLET IS RECOMMENDED.
THE MONITOR TO FIT A 2-SLOT OUTLET.
IF THE
MUST BE
A 3-WIRE
GROUNDED
NEVER ADAPT THE 3-PRONG PLUG FROM
OUTLET HAS ONLY TWO SLOTS, SEE THAT IT
IS REPLACED WITH A 3-SLOT GROUNDED OUTLET.
The 78670A and 78671A store high voltage energy and are capable of delivering up to
360 Joules. Simply removing the defibrillator from the Quick-Mount Power Base or
unplugging the power base will not remove power from a battery-powered instrument.
The ENERGY SELECT switch must be placed in the OFF position or the discharge
buttons pressed to discharge a charged instrument. As a safety feature, the
defibrillator is designed to automatically discharge internally if it has been
charged for more than 32 seconds.
The 78670A and 78671A are designed with all plastic covers and controls to minimize
shock hazard. Because a battery-powered instrument has no reference to earth
ground, small static charges can be generated during defibrillator discharges. The
static charges present a minor shock potential to the operator, BUT ONLY through
the exposed metal surfaces (ground connector connector, IV ECG OUT, and recorder
housing).
1.12
Avoid touching these surfaces during battery operation.
MOUNTING (78668A POWER BASE)
Mounting instructions for the 78668A Quick-Mount
6 of the Operating Manual.
Power Base are located in Section
1-15
SECTION I - GENERAL INFORMATION
Models 786 70A/786 71A
78670A-l
/^%
WARNING
REPLACEMENT POWER CABLES MUST PROVIDE CORRECT POLARITY AND GROUNDING
ILLUSTRATED. INCORRECT CONNECTIONS CAN RESULT IN AN ELECTRICAL HAZARD.
AS
Table 1-3. Power Cable Sets.
Table 1-3 contains descriptions, Hewlett-Packard stock numbers and wire color codes for AC power cable
sets that connect to instruments manufactured by the HP Medical Products Group.
AC POWER CABLE SETS (U.S.A.)
FEMALE CEE 22 IEUROPA)
MALE NEMA (HARD-WIRED)
(HOSPITAL GRADE)
^-
3"
c
<L)
BROWN OR BLACK
<E)
iN)
GREEN/YELLOW
LIGHT BLUE OR WHITE
0
•
<L)
—HE)
Cffl
<N)
o o
BROWN OR BLACK
GREEN/YELLOW
<N> WHITE
3) (/>
c
MALE CEE (EUROPA)
E)
(.
>2
Oh
m ^
0
ID
GREEN/YELLOW
BLACK
r
LIGHT BLUE OR WHITE
MALE NEMA S0°
(HARDWIRED)
MALE NEMA (MOLDED)
f ^ , —<N) WHITE
<N> WHITE
#V-(E) GREEN/YELLOW OR GREEN
MSC
[_—*-^-(Ll BLACK
E) GREEN/YELLOW
<L)
BLACK
MALE NEMA (HARD WIRED)
<N) WHITE
C-~r-(E) GREEN/YELLOW
'L) BLACK
E
-
EARTH OR SAFETY GROUND
N
-
NEUTRAL OR IDENTIFIED CONDUCTOR
L
-
LINE OR ACTIVE CONDUCTOR
CONNECTORS
MALE END
POWER CABLE
AWG/NO. OF
HP PART
FEMALE END
LENGTH
CONDUCTORS
NUMBER
NEMA (HARD •WIRED)
CEE 22
2.4M
(8.0 FT)
16/3
8120-1931
NEMA (HARD WIRED)
CEE 22
3.6M
(12.0 FT)
16/3
8120-1932
NEMA (HARD WIRED)
5 CM (2 IN.) STRIPPED ENDS
4.5M
(15.0 FT)
14/3
8120-1706
NEMA (HARD •WIRED)
2.6 CM (3 IN.) STRIPPED ENDS
3.6M
(12.0 FT)
16/3
8120-1935
NEMA (HARD •WIRED) HOSPITAL GRADE
CEE 22
2.4M
(8.0 FT)
16/3
8120-3493
NEMA (HARD •WIRED) HOSPITAL GRADE
CEE 22
3.6M
(12.0 FT)
16/3
8120-1993
NEMA (HARD WIRED) HOSPITAL GRADE
CEE 22
4.5M
(15.0 FT)
16/3
8120-1995
NEMA (HARD WIRED) HOSPITAL GRADE
CEE 22
76 CM
(2.5 FT)
16/3
8120-1996
NEMA (HARD •WIRED) HOSPITAL GRADE
2.6 CM (3 IN.) STRIPPED ENDS
3.6 CM
(12.0 FT)
16/3
8120-1994
NEMA (HARD •WIRED) 90°
CEE 22
2.4M
(8.0 FT)
16/3
8120-0609
NEMA (HARD WIRED) 90°
CEE 22
76 CM
(2.5 FT)
16/3
81200610
CEE 22
CEE 22
76 CM
(2.5 FT)
16/3
8120-1900
CEE 22
CEE 22
2.4 M
(8 FT)
16/3
8120-2133
CEE 22
2.6 CM (3 IN.) STRIPPED ENDS
76 CM
(2.5 FT)
16/3
8120-1933
CEE 22
2.6 CM (3 IN.) STRIPPED ENDS
1.2M
(4.0 FT)
16/3
8120-1934
NOTE: OTHER COUNTRIES SUCH AS CANADA. JAPAN (100 or 200 VOLTS).
MEXICO, PHILIPPINES, AND TAIWAN MAY USE SOME OF THE ABOVE SETS.
CONSULT YOUR NEAREST HP SALES OFFICE.
1-16
/-%
SECTION I - GENERAL INFORMA TION
Models 78670A178671A
78670A-1
Table 1-3. Power Cable Sets (Continued).
AC POWER CABLE SETS (NON USA)
EAST AND WEST EUROPE. SAUDI ARABIA.
UNITED ARAB REPU8LIC
MALESCHUKO
FEMALE CEE 22 (EUROPA)
LIGHT BLUE
BROWN
GREEN/YELLOW
El
GREEN'VELLOW
BROWN
Nl
LIGHT BLUE
8120 1609120ml
8170 169212 0 m. FEMALE ENO IS RIGHT ANGLEl
8120 146012 4 m. FEMALE ENO IS STRIPPED!
8120 1690 14 S ml
AUSTRALIA. NEW ZEALAND
FEMALE CEE 22 (EUROPA)
LIGHT BLUE OR BLACK
IN
GREEN/YELLOW
LIGHT BROWN OR RED
8120 136917 2 ml
E
&
ILI
LIGHT BROWN OR RED
IEI
GREEN/VELLOW
INI
LIGHT BLUE OR BLACK
GREAT BRITIAN. CYPRUS. NIGERIA.
RHODESIA. SINGAPORE
FEMALE CEE 22 (EUROPA)
LIGHT BLUE
GREEN/VELLOW
IE
LIGHT BROWN
IL
8120 Ifil 122ml
II
LIGHT BROWN
El
GREEN'VELLOW
Nl
LIGHT BLUE
NOTE: OTHER COUNTRIES USE MORE THAN ONE OF THE ABOVE
POWER CABLE CONFIGURATIONS. FOR CORRECT POWER
CORD SET IN YOUR AREA, CONSULT YOUR NEAREST HP
SALES OFFICE.
1.13
OPTIONAL ACCESSORY CABLES
Synchronizing from a Bedside Monitor
The 78670A and 78671A can be externally synchronized by applying a high level ECG
signal through a 1000:1 divider, to the ECG LEADS input.
A molded cable assembly
is available for this application (P/N 14482A).
High Level ECG Output Cable
When it
is necessary to connect
the 1 volt
ECG output to*another
instrument, an
accessory cable is available (P/N 8120-3164). This (8) foot cable has a right
angle mini-phone plug on one end and a standard phone plug on the other end.
1-17
SECTION I - GENERAL INFORMA TION
Models 78670A178671A
78670A-4
STERILIZATION OF HEWLETT-PACKARD'S INTERNAL PADDLES
AUTOCLAVING
Only the internal paddles supplied with the defibrillator are autoclavable (autoclave temperature
275° F (135°C) maximum. To maintain sterility after autoclaving, good packaging is essential.
NOTE
The high temperature and humidity to which the paddles are exposed during
autoclaving shorten their useful life. Typically, HP's internal paddles can
withstand up to 200 autoclave cycles before sustaining damage to the cables or
discharge switch.
GAS STERILIZATION
The paddles and other defibrillator accessories (cables, etc.) will not be damaged when subjected
to the following gas sterilization procedure:
1.
2.
Clean the exterior of the item to be sterilized to remove surface contamination.
Dry the item completely to avoid formation of toxic ethylene glycol during ethylene
oxide sterilization.
3.
Use ethylene oxide/freon mixture as the sterilant (12% ethylene oxide with 88%
Freon-12).
4.
Follow the operating instructions provided by the manufacturer of the gas sterilizer
with these reminders:
a.
When sterilizing the external paddles, sterilizer temperature must not exceed
54.4° C (130° F). Temperatures that exceed this limit could affect the
reliability of the item or damage its components.
1-18
b.
Maximum gas pressure not to exceed 6 psi (310 mmHg) for up to six hours.
c.
At the end of the sterilization cycle, use vacuum (-26 inches of mercury)
for 5 to 15 minutes to expel some of the residual gas.
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-2
SECTION II
THEORY OF OPERATION
2.1
INTRODUCTION
This
section
describes
the
Defibrillator/Monitors.
block diagram.
2.2
The
theory
of
operation
first section is a
of
the
78670A
brief overview with
and
78671A
a simplified
The second section covers circuit theory in detail.
SYSTEM OVERVIEW
Refer to the block diagram, Figure 2.1.
boards: an
ECG switch
board, an
The ECG section consists of three circuit
analog input
board and
a digital
gain control
board.
The ECG analog board is divided into two sections, an isolated or "floating"
section which isolates the patient from potentially unsafe voltages, and a grounded
section.
RA fc
LEADS
LA fc
RL
/
MEMORY OISPLAY/
ANALOG ECG BD
ECG
SWITCH BD
78670-60215
TIMING BD
78670- 60155
78660-60170
ECG DIGITAL BD
1
FLOATING
1 GROUNOED
SECTION
1 SECTION
\
CRT
1
""•"
i
78660-60140
DEFLECTION BD
78660-60180
uP
1
,
i
a
SYNC
1 '
O
(J
r
DEFIB CONTROL BD
78670-60195
O
a
POWER SUPPLY BO
78670-60110
HEART RATE/REAL
u
78660 60210
j 7866060260
j (78671A ONLYI
1 (78670AONLY)
<
Q.
{TO AIL CIRCUITS!
uP
1
j HEART RATE BO j
L
_i
L
I
j
1
i i
i '
DEFIBRILLATOR HV
PA DOLES
SECTION
78670 60120
BATTERY
78660-60401
4
'
EXTERNAL
TOWER INPUT
< '
RECORDER CONTROL
BD
RECORDER
78670-60200
uP
Figure 2-1. Model 78670A Block Diagram.
2.2.1
ECG Switch
Board and Analog Board
The ECG leads and paddles inputs enter through the floating analog section. Each
input has protective networks to prevent transient voltages from damaging the ECG
amplifiers.
The inputs are selected by a LEADS/PADDLES switch. Front panel
mounted LED's indicate the source selected.
Following the source selector is a fixed gain differential amplifier. If one of
the leads becomes disconnected, it unbalances the amplifier.
The unbalanced
condition is sensed by a detector circuit which flashes the LEADS indicator lamp.
2-1
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-1
s*%
The output from the differential amplifier is chopper modulated and transformer
coupled to a demodulator, which is in the grounded side of the ECG circuit. The
denodulated signal is amplified about 11.5 times and is passed over to the ECG
digital board.
The patient's impedance (measured at 31.25 kHz) at the paddles is reflected across
a transformer to the grounded side. This PDZ (Pre-Discharge Impedance) is then
converted to a DC signal which will later be used to indicate the patient
conductivity between the paddles.
2.2.2
Digital ECG Circuits
The ECG from the analog ECG board first goes through a notch filter (switch
selectable for 50 or 60 Hz operation) to remove any extraneous, power line related
signal.
Then the signal enters a variable gain amplifier.
The gain may be
manually controlled, or if in the auto gain mode, the gain
microprocessor.
The microprocessor also supplies signals
loudspeaker
(beeper), control
an analog
to
digital converter
is controlled by a
to drive a small
and furnish
sync
signals to the defibrillator control for synchronized cardioversion.
2.2.3
CRT Timing Circuit and Memory
3.6 seconds of ECG information is displayed on the monitor CRT.
is added, old information is erased.
The
As new information
information is stored in a semiconductor
memory which refreshes the CRT display every 16 milliseconds. This circuitry also
includes the clock oscillator for the memory, and the erase bar generator. The
erase bar generator turns the CRT beam off at the point where new information is
being written on the screen. After processing, the digital ECG signal is changed
back to analog by a D to A converter.
2.2.4
CRT Driver Circuit
This circuit provides the beam positioning drive signals for the CRT deflection
yoke, CRT intensity blanking and brightness biasing. It consists of horizontal and
vertical amplifier channels plus an intensity control amplifier.
2.2.5
Heart Rate Circuit
This circuit controls the heart rate displayed on the CRT.
It controls the alarm
audio output and provides inputs for the ALARM and SERVICE switches. Resistors are
added to an I/O device to inform the recorder microprocessor of the language and
real time clock options.
2.2.6
Real Time Clock
This section contains a clock integrated circuit which keeps track of month, date,
and time in hours and minutes. This information is printed out on the strip chart
during recorder operation. The clock entry may be changed to reflect any changes
required (time zone change, etc.).
2.2.7
Recorder Circuit
This circuit controls the strip chart recorder operation and annotation. It also
calculates the heart rate and sends the digital information to the heart rate
2-2
SECTION II - THEOR Y OF OPERA TION
Models 78670A(78671A
78670A-2
circuit for the
CRT display.
The recorder control microprocessor
the recorder control switches and the
has inputs from
defibrillator CHARGE and DISCHARGE switches.
The microprocessor controls the recorder drive motor, stylus pen heat and
annotating print head. Amplified signals from the display timing circuit drive the
recorder galvanometer.
The recorder prints out
real time and date, indicates patient
impedance and notes
stored and delivered energy.
The recorder starts automatically
defibrillator CHARGE switch is pressed and released.
2.2.8
whenever
the
Defibrillator Control
The primary task of the defibrillator control circuit is to control the charging
and discharging of the defibrillator HV capacitor and calculate the post-discharge
delivered energy, peak current, and patient resistance. Other functions include
control of the paddle contact signal and flashing the low battery indicator LED.
2.2.9
Defibrillator H.V. Circuits
The high voltage circuitry consists of a high voltage DC to DC converter, high
voltage defibrillator energy storage, discharge circuits and monitoring and control
to interface with the defib control microprocessor.
The high voltage supply consists of a flyback circuit driven by a pulse width
modulator, which provides fixed frequency, variable duty cycle control.
If the
battery is low, charging stops until the battery voltage recovers giving maximum
available energy without disrupting the other circuits.
The battery voltage is stepped up by the flyback transformer, rectified and stored
in the H.V. defibrillator capacitor. Metering resistors provide H.V. samples to
the control microprocessor so that charging stops when the selected energy level is
reached. This level is maintained until the energy is discharged.
After H.V. charging, the energy is discharged either through the patient relay to
the defibrillator paddles, or through the safety relay to a load resistor. The
discharge path depends on the signal received from the microprocessor.
If the patient relay is activated, a current transformer circuit provides a peak
current signal to the microprocessor, as a measure of discharge performance. When
the patient relay is in the nonactivated position, the paddles are connected to the
ECG amplifier to permit monitoring from the paddles.
if the battery voltage falls below 9.5 volts, while charging the defibrillator, the
H.V.
circuit is
locked
out.
This
allows additional
monitoring
time but
the
defibrillator cannot be charged until the battery is replaced or the unit connected
to an external power source.
H^\
2-3
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-2
2.2.10 Low Voltage and CRT Power Supply
This circuit consists of a pulse
flyback transformer has multiple
required.
^
width modulator controlled flyback supply. The
secondaries which furnish the various voltages
Input voltage from the battery can vary from 9.0 to 13.5 volts. If this battery
voltage falls below 9.0 volts, the power supply is locked out of operation to
prevent damage to the battery.
In addition to the low voltages, this circuit furnishes +200 volts and +5000 volts
to the monitor CRT.
The +5000 volts is derived through the use of a voltage
multiplier.
In order to stabilize output voltage, with varying battery voltage, a sample of the
secondary voltage is fed back to the pulse width modulator which controls duty
cycle, thereby controlling output voltage. Fixed voltage regulators are employed
for circuits that have more stringent voltage regulation requirements.
2.2.11
Battery and Battery Relay
The defibrillator is powered by a 12 volt nickel-cadmium battery pack.
A fully
charged battery, that is in good condition, can provide 2.5 hours of monitoring
time or 50 full power defibrillator charge cycles.
The battery relay connects the defibrillator circuits to the battery through /^
normally closed contacts. When the defibrillator is operated from an external
power source, the relay disconnects the battery from the defibrillator and onto a
battery charging supply.
The defibrillator is then connected to the external
supply.
If the external power is interrupted by
power line failure, the relay switches the
system back to battery power.
2.2.12
Quick-Mount Power Base 78668A
This accessory allows the defibrillator/monitor to operate from 115-230 volts, 50
to 60 Hz power lines. It furnishes three outputs to the defibrillator: 1. A
current limited battery charging output maintains the battery at full charge.
Charging takes place at all times whether or not the defibrillator is turned on; 2.
A regulated 12 volt supply furnishes power to all other circuits except the
defibrillator H.V.
supply; 3.
The defibrillator section operates from a high
current unregulated supply. See Section VII for all additional information of the
power base.
2.2.13
Spare Battery Charger 78669A
The battery charger is a separate, self-contained unit that will charge two battery
packs at a time. It has LED's which indicate that energy is being supplied to
charge the battery, and when the battery has been on charge for eight hours (half
charge) and for sixteen or more hours (full charge). Like the AC power pack, the
battery charger operates from 115-230 volts,
additional information on the battery charger.
2-4
50-60 Hz.
See Section VII for
all
^%
'
SECTIONII - THEOR Y OF OPERATION
Models 78670A/78671A
78670A-1
Figure 2-2. Detailed Block Diagram, Model 78670A (fold-out).
fl*
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3
DETAILED THEORY OF OPERATION
(Refer to the detailed block diagram Figure 2-2)
2.3.1
ECG Switch Board 78670-60215
2.3.1.1
ECG Source Switch (Fig. 2-3).
The 5 pole switch on this board selects the source of ECG.
Either the paddles or
one of the 3 leads configurations is connected with the AC differential amplifier
and the leg drive op amp. It also indicates which source has been selected by
lighting either the "LEADS" or "PADDLES" LED on the front panel.
2.3.1.2
Protective Circuitry
DSl, DS2 and DS3 along with the 1 K ohm resistance built into the ECG leads limits
the input to the AC diff amp to 270 V or less.
ECG Analog Board 78670-60155
2.3.2
The ECG analog board consists of a floating section, which isolates the patient
from potentially unsafe voltages, and a grounded section. The selected source of
ECG is amplified, filtered and transferred to the grounded section for further
processing. Circuitry for measuring PDZ is included on this board.
LA
DIODE LAMP
H.V.PROTECTION
RL
I
RA
AC DIFF. AMP.
1
L.J
t
NEON LAMP
H.V.PROTECTION
NEON LAMP
H.V. PROTECTION
R9
STERNUM _j
^l
_ n
PADDLE -***T^
APEX ^\A.
PADDLE r^
PADDLES LED
LEADS LED
&
^
&Figure 2-3
2.3.2.1
Protection Circuitry (Fig. 2-4)
The paddles ECG amplifier input protection circuits consist of resistors Rl, R2,
neon lamps, DSl, DS2 and spark gap El. The spark gap protects the LEADS/PADDLES
switch from high voltage breakdown in the unlikely event that defibrillator high
voltage is applied between the ECG source leads and paddles.
This can only occur
if the 78670/78671 is used with another
defibrillator.
CR8 through CR13 clamp the
2-7
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
R43, R44 and R45
inputs to within 0.7
volts above +Vcc and 0.7 volts below -Vee.
limit the input current to less than 5 mA.
1.5K
ANY 2 INPUT/ C-
-o |t>-
-AAA-
>27K
-^W\,
< ±5mA
I
I
I
CR12
CR9
I
270V
MAX
HV
'CC
TO AC DIFF
AMP OR RLD
'EE'
CRIO
>1.5k
,S>.
•AAA
CRI3
>27K
-^WV—
NEONS FIRE
AT I35V
Figure 2-4
2.3.2.2
Differential Amplifier (Fig. 2-5)
Ql through Q6 form a high gain AC amplifier with differential input and output.
R12, R14, R31, R33, C5 and C17 set the gain at 23 above 0.32 Hz.
Gain is unity
below 0.01 Hz.
R8 and R27 set the input bias current near 60 nA.
°^\<be}-
'•VSEr^
DIFF
OUT
INPUT
•RI2
C5
•R3I
CI7
EQUIVALENT CIRCUIT
Figure 2-5
2.3.2.3
Right Leg Drive (RLD) (Fig. 2-6)
Common mode voltage, from the differential AC amplifier output is amplified 100
times by U2, inverted and driven back into the right leg of the patient. If the
paddles are selected, the signal is fed back through Rl and R2 between the inputs.
RLD forces the average voltage at the outputs of the differential amplifier (the
junction of R12, R13 and R23 and the junction of R24, R31 and R32) to be zero.
Without any offset voltage from the patient, the voltage at the base of Ql and Q6
should be about
Vbe(Q2) (R12/R10) + Vbe(QlO) = 0.8 volts
2-8
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-l
The output of RLD U2, which supplies bias current
to Ql and Q6, should be about 10
to 15 mV higher.
C13 rolls off the feedback of the RLD at about 35 Hz for stability.
RA
TO CHOPPER
MODULATOR
U3
DIFF OUT
LA
—i-_
CI3
.0047
^
I9.6K
I9.6K
-VVV-f—*W\/—
LL/RL
^
Figure 2-6
^s
2.3.2.4 ECG Leads Off Indicator (Fig. 2-7)
The operation of this circuit is only visible in the LEADS mode,
RLD supplies
input bias current to the AC differential amplifier. If any one or more of the 3
leads should become disconnected from the patient, one or both halves of the
amplifier turn off and RLD goes high. Beyond a threshold of about 2.9 volts, set
by R6 and R7, comparator UlA goes low and allows U1B to oscillate at about 2 Hz.
This causes the LEADS LED to flash, When UlA goes low, the chopper modulator U3 is
disabled through CR1 and CR3. This results in a flat line on the monitor.
TO RL
+VCC
+VCC
COMPARATOR
2 Hz
R4I
OSCILLATOR
R6
R37
-Vrr
EE
LEADS
-V EE
CRI
H4-
AIDSI
c
V
CR3
v
TO
U3
-w-
Figure 2-7
2-9
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3.2.5
Chopper Modem and Power Supply (Fig. 2-8)
The ECG signal from the differential amplifier is modulated by chopper U3. BY
modulating the signal with a high frequency chopper, the ECG signal can be passed
on to the grounded section via signal isolation transformer T2. At the grounded
side, the chopped ECG is demodulated by U55 to reproduce the actual signal again.
The chopper drive signal is rectified by the full wave bridge CR4 through CR7 to
provide plus and minus 4.2 volts (+Vcc and -Vee) on the floating section. Series
connected R46 and R50, 22 megohm each, tie the floating section to the grounded
section. Function of these 2 resistors is to prevent static charges from building
up between the two sections.
SIGNAL
CHOPPER
MODULATOR
ISOLATION
TRANSFORMER
CHOPPER
DEMODULATOR
T2
•W
^o
INPUT
FLOATING
GROUND
ANALOG
SYSTEM
GROUND
U3
0UTPUT
-o—o-
U55
-cr
o
-o—o-
POWER
T
V
ISOLATED
TRANSFORMER <Q> TP5I
Tl
V 31.25 kHz
ISOLATED
POWER SUPPLY
—- Q5I
5D
052
R46
R50
22 M
22M
sT" ~~"*
SIGNAL
Jl
IN
rvir
DEMODULATED
SIGNAL OUT
MODULATED SIGNAL
Figure 2-8
2.3.2.6
EMI Rejection
The following components serve to reduce the susceptibility of the ECG amplifier to
electro-magnetic interference:
Rl, R2, CI, R15, CIO, R34, C12, R44, C23, R45, C24, Cll, Ll-4,
C8, C9, C14, C15, R20, C6, R25, R26, C16, C21, C22.
In addition to EMI
suppression, Rl, R2, R44, and R45 are part
protection circuitry described earlier.
2-10
of the high voltage
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-l
g^
Grounded Section
2.3.2.7
Chopper Driver (Fig. 2-9)
U51B is connected as a level translator, translating a 62.5 kHz clock of 0-5 volt
level to +/-3.75 volts. U52B divides this signal by 2 to provide complimentary
phase chopper signal of 31.25 kHz. These two signals alternately turn on Q51 and
Q52 to drive the power-isolation transformer Tl. C52 and C53 AC couple the chopper
signals to Q51 and Q52. If for any reason the chopper signal is lost, the AC
coupling prevents Q51 and Q52 from shorting out the +5D power supply. U52A delays
the chopper drive to the demodulator by a small amount, to help compensate for
phase delay in Tl and T2.
Figure 2-9
2.3.2.8
Baseline Restore (Fig. 2-10)
The ECG signal from the demodulator U55 is filtered by R66 and C62, to remove
chopper artifacts. It is then AC coupled by the high pass pole formed by C60 and
R70. If the baselne begins to drift, it is sensed by the microprocessor which
turns on Q53 for about 1.5 seconds. When Q53 is on the pole that was at 0.2 Hz is
shifted to 4.2 Hz, which is determined by C60 and the parallel combination of R70
and R71.
Put in another way, when Q53 is conducting, the excessively high DC
potential on C60, which accompanies a high baseline, is discharged through R71.
R66
2.87K
C60
4/iF
-3dB -
/
-WV,—
;R7I
£/
q/
10 K
U55
C62
DEMODULATOR
'.OI/iF
:R70
&/
a/
.*>/
>I96K
053
ACTING LIKE
A SWITCH
/
7
O
0.2Hz
42Hz
5500Hz
J^N
Figure 2-10
2-11
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3.2.9
Fixed Gain Stage (Fig.2-11 A)
R58, R61 and U51A form a gain stage with a fixed gain of
gain at approximately 600 Hz.
2.3.2.10
11.7.
C55 rolls off the
Zero Offset Potentiometer
The zero offset adjust potentiometer, R73, removes any offset voltages that may be
present in the op amp U51A and succeeding op amps on the ECG DIGITAL board. R67
and R69 bias the non-inverting input of U51A, at 8.2 mV above ground, so that the
zero offset potentiometer, connected between
remove both positive or negative offset.
2.3.2.11
Calibration Potentiometer
When the
CAL switch
A1-S5 is
an
accurate +12V
pressed, a calibration signal
and ground,
is applied
can
through
potentiometer R72, R64, R62 and R65.
R72 is adjusted so the magnitude of the
calibration signal is equivalent to 1 millivolt applied to the ECG inputs. Q2 on
the ECG DIGITAL board informs the microprocessor that the CAL switch is activated.
Col Adj
AIS5
CAL SWITCH
R65
I
'WV-
<i
W\r
5A
R72
C64
<R64
/*,%
R62
C55
R58
•AAV-
ECG SIGNAL
WITH 8.2mV DC
BIAS
•*
ECG SIGNAL
TO DIGITAL BD
(78660-60140)
Figure 2-11A
2.3.2.12
Analoq Power Supply
U53 and U54 supply plus and minus 5 volts for use only by the analog circuits on
the ECG boards.
The ground on the ECG ANALOG board and on the analog portion of
the ECG DIGITAL board is connected to the instrument ground at only one point.
This basically isolates the ECG's sensitive circuits from the rest of the
instrument. R51 and R52 reduce the heat that must be dissipated by U53 and U54.
CR53 and CR54 prevent U53 and U54 from latching up in the event
are lost for a yery short period of time (milliseconds).
2.3.2.13 Electromagnetic Interference Rejection
R59, R60, C56 and C57 make the circuits less susceptible to EMI.
2-12
that +12V or -12V
^%
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3.2.14
Paddle Contact (PC)
The 31.25 kHz signal at TP51 is attenuated by R78, R85 and U58A to produce a square
wave of 25 mVp-p for sensing PC. U56 acts as a switch for disabling the circuit
when external paddles are not being used or if the external paddles are placed in
their storage pockets.
U58B and U58C form a gain stage where, at 31.25 kHz, the gain is essentially
-R83
R84 + Rpatient
(See Fig. 2-11B) U58B and U58C are cascaded to increase the loop gain and may be
considered as one op amp.
C70 is a compensating cap and does not contribute to the
gain equation above.
U58D and associated resistors and capacitors make up the band pass filter which
selects only the 31.25 kHz harmonic for measuring PC, the output of which is a
clean sine wave. R91 is for adjusting gain and Q.
U57, R74, CR55, C65 and R75 together make a peak detector which holds the peak
value of the sine wave in C65. This DC output is a function of the resistance
(impedance) placed between the paddles. R76 and R79 perform a level shift on the
incoming sine wave to give the desirable PC vs. patient resistance curve.
R83
I96K
-°v0UT
R83
R86
27K
PADDLES
-^SAA.—
R82
R PATIENT
IK
V|No
R84
vwv
RPATIET
w.
'OUT
Equivalent Circuit
Figure 2-1 IB
2-13
SECTION II - THEOR Y OF OPERA TION
Models 78670A\78671A
78670A-l
2.3.3
ECG Digital Circuit Board (78660-60140)
(Refer to detailed block diagram, Figure 2-2,and detailed schematic, Figure 6-4.)
The ECG DIGITAL board
contains a microprocessor, a 50/60 Hz
notch filter, an auto
gain attenuator, a voltage to frequency converter (V/F) and an auto baseline
circuit. The power for the analog circuits on this board, is supplied by U53 and
U54 on the ECG
ANALOG board.
Digital ground
on this
Analog ground also comes from
board is the same
ground as
the ECG ANALOG board.
used by the rest
of the
instrument.
2.3.3.1
50/60 Hz Notch Filter (Fig. 2-12)
U4 together with C5, C6 and R9 through R18 form a bi-quad filter.
board mounted switches, SI
Hz reject,
or no notch.
and S4 through S8 select the notch for
The
output from the notch
The circuit
either 50 or 60
filter goes to the auto gain
attentuator.
Figure 2-12
2.3.3.2
U2,
Auto Gain Attenuator (Fig. 2-13)
U5A, R2 through
attenuator network.
R6 and R19 through R23 form a microprocessor controlled
This allows
the automatic
selection of
gains, depending on the input ECG signal level.
five different
The relative
ECG
gain of any two
adjacent stages is 1.4.
2.3.3.3
When
the
Manual Variable Gain
MANUAL/AUTO
switch
A1-S6 is
in
the
MANUAL
position
(open),
the
microprocessor, U6, selects channel 5 in U2.
This connects the variable gain
potentiometer A1-R6 to U5A. The potentiometer provides a 20:1 gain variation.
2-14
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
-AIR6 5R49 £R2
1
^
>R3 >R4 >R5
"I9.IK >R6
>30.IK>45.3K>68.IK>I00K
VARIABLE
GAIN
CONTROL
AGC 3
FROM U6
ECG
SIGNAL >
V
U2
CHANNEL SELECT
R2I
"VAA-
IN
R23
•—•• ECG OUT
Figure 2-13
2.3.3.4
Voltage to Frequency Converter (V/F) (Fig. 2-14)
A V/F converter is made up of integrator U5B, comparator U5C, flip-flops UlA and
UIB, FET Q4, charge capacitor C15, R24, R25 and R41.
This is a charge dumping
circuit where the input charge to the integrator is balanced by periodic discharges
through Q4.
Each discharge lasts exactly 8uS. A/D conversion is accomplished by
counting the number of discharges in a fixed period.
The nominal operating rate is 128 discharge pulses in 4.096 milliseconds, baseline
condition (without an ECG signal).
The maximum rate is 255 pulses, in the same
period.
At the beginning of every A/D conversion, UlA is set, UIB reset and charge
capacitor C15 discharged by Q5. This eliminates any uncertainty in conversion
which could be introduced if the state of UlA or UIB or the charge on C15 was
unknown at the beginning of the conversion.
2.3.3.5
Auto Bias (Fig. 2-15)
U5D, R36-R40, C12, C14, C14, C17, C25 and U3A form an auto baseline circuit which
drives the V/F converter to an average count of 128/4.096 mS. U3A buffers the auto
zero signal from the micro- processor before it goes to integrator, U5D.
Fig. 2-15
2.3.3.6
Microprocessor
The microprocessor, U6, counts the V/F, outputs the ECG signal in digital form,
detects R-wave, selects the proper channel in the auto gain attenuator, and
performs various other tasks.
2-15
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
ECG
Q
05 (ACTING AS A SWITCH)
^o
•R24
INTEGRATOR
AUTO
BIAS °
R4J
COMPARATOR
VW"
+ \.
CR6
U5C>
W•R34
CR2
W
BIASED AT
-0.7 VOLTS
0
D
+ 5D
*
UlA
_L
Q4
CR7
Q
D
w
UIB
R25
Q
R<
*
-5A
n__n__n_4ms
U6 PIN 30
QR s<
AfjiS
Figure 2-14
R37
20M
-AAA—
TO V/F U5B
BIASED© 2.5V
FROM U6
MICROPROCESSOR
INTEGRATOR
Figure 2-15
2.3.4
Microprocessor Reset "Tickle" Circuit (Fig. 2-16)
Should the microprocessor ever hang up due
free-running oscillator formed
resets the microprocessor.
When the microprocessor is
to a defibrillation or other noise, the
by Q3, U3C, U3D, Rl,
R8, R28, R32, CI,
operating properly, C3 couples a signal
C3 and CR4
that resets Q3
ewery 4.267 milliseconds. If the signal from the microprocessor is lost, U3D will
oscillate until the microprocessor is reset and the AC signal appears at Q3.
)22uF
TICKLE
1/
PULSE " I V
R8
tern
i
IOK
iur\
yi
12
-^
♦
MICROPROCESSOR RESET CIRCUIT ?I9K
Figure 2-16
2-16
•
50
6£¥*•
8uF
iR5°
>[8K
SECTION II - THEOR Y OF OPERA TION
Models 78670A1786 71A
78670A-1
^
2.3.4.1
Beeper
U8, on the memory circuit board, generates a continuous train of pulses with a
frequency of approximately 488 Hz. This signal and the R-wave signal connect to
the inputs of U3B.
At the detection of each R wave, U3B is
enabled for about 160 mS.
488
the
Hz
signal
goes
to Ql
to drive
speaker.
Volume
is
When enabled, a
controlled
by
potentiometer A1-R5.
2.3.4.2
Electromagnetic Interference Rejection
The following
components serve
to reduce
EMI susceptability
and/or protect
I/O
lines on the processor:
C4, R17, C7, R20, C9, R30, C28, C29, C30, C31, R31, C19, R33,
C18, R35, C24, R46, R47.
2.3.5
Memory/Display Board 78660-60170
2.3.5.1
Functional Overview
The semiconductor memory stores 3.6 seconds of ECG waveform for display on the CRT.
The timing signals to control memory, the horizontal ramp generator and a CRT
signal multiplexer are also located on the memory board. Signals generated for the
CRT are shown in figure 2-17.(See Figure 6-5 for detailed schematic)
VERTICAL
4mSECG
•+•— 4mSBLANK
-4mS—
DIGITS
-4mSBLANK
Figure 2-17
is a IK x8 random access static
The memory element U9
MOS memory (RAM) integrated
memory cells; each cell containing 8 bits of data. Every 4
digital microprocessor, located on the digital ECG board,
converts the ECG signal to an 8 bit
digital signal, which is stored in the memory,
The memory cells are sequentially addressed from location 0 to 1023 by signals from
circuit.
It has 1024
milliseconds the ECG
an address
counter U5B
converted back to an
U6B and U7B.
The 8
bit contents of
each cell
is later
analog signal by the digital to analog (D/A) converter, U13.
Analog signals are created for both the CRT and the recorder.
2-17
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
A ramp
generator, U17C, controls
the horizontal position
of the CRT
beam.
When
memory location
0 is addressed, the CRT beam is at the extreme left.
It moves
linearly to the right as addresses are sequenced. Each location corresponds to a
specific horizontal location on the CRT screen, with 1023 located on the extreme
right.
The 8 bits of data in each cell are converted into one of 256 possible vertical
locations. Zero is at the bottom of the screen; 128 is beam center and 256 is the
top.
The time required
to read the entire memory is 4 milliseconds.
Four seconds are
required to store in all 1024 cells, therefore, the CRT signal is 1024 times the
input frequency. Thus a signal of 10Hz into the ECG amplifier is presented to the
CRT as a 10kHz signal.
ECG information is received, the oldest information is lost from memory.
For a graphic description of the read-write sequence, see Figure 2-18.
Line 1
represents the RAM memory from 0 through 1023. Line 2 is the write pulse which
advances one memory cell with each output pulse. In the real time mode, the 1025
In the delay mode the 1025 pulse writes
pulse is both the write and read command.
in the new information and the 1026 pulse reads the next memory cell which is the
oldest information in memory.
As new
1023
0
12 3 4 5 6
1023
0
1 1 1 1 1 1 1 "'"
12 3 4 5
0
6
1 1 1 1 1 1 I""
1023
12 3 4 5 6
1 1 1 | 1 1 1'""
ADDREJ>S
74
WRITE 73
75
RIGHT
HORIZ
.EFT
Figure 2-18A
I023
0
I 2
3
4 5 6
I I I I I I I'"-
I023
0
2 3
4 5 6
I I I I r~~
I
0
I
I023
2
3
4 5 6
I I I I \—
ADDRES>s
WRITE 73
74
^
y/
HORIZ
75
RIGHT
.EFT
Figure 2-18B
2-18
/^%
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
Erase Bar
In the FIXED TRACE mode the erase bar is a signal which turns off the CRT for a short
interval just after new information is written into memory.The operator is then able
to differentiate between old and new information on the CRT. In the MOVING TRACE mode
the erase bar is not used. The new information, in this mode, is always at the right
side of the CRT. Refer to Figure 2-19 for a simplified erase bar generator circuit.
HORIZ
RETRACE
UI2B
WRITE >
CLK
CRT
^
UIOC
UI6
MUX
RESET
256/iS
AFTER >
WRITE
Figure 2-19
2.3.5.2
Oscillator and Johnson Counter (Fig. 2-20)
A one MHz signal is provided by a CMOS, crystal controlled oscillator U18C. This
signal drives a Johnson counter, Ul, which produces the four phase timing signals.
Phase 1 is the clock for the address counters.
provides a 4 microsecond signal to the ECG
and recorder sample/hold FETS.
Phase 2 resets the 1025 counter and
digital board.
Phase 3 enables the CRT
Phase 4 resets the Johnson counter.
JOHNSON
COUNTER
ni
\j\
l^osc
Ul
rsBUFFER
0„
ImHz
VJcXt
JKJ-*
\JtLU
3K)
1
>
1•
1 "-' 1
1
•
'
'
n
04
\
"—
n
n
CLK
RESET
—
n
[1
L
<>
Figure 2-20
2.3.5.3
1025 Counter (Fig. 2-21)
Recall that the memory has 1024 cells and a write occurs to a sucessive cell each
time. This is accomplished with a counter which resets itself after 1025 counts.
The 1025 pulse or write signal output of U11A enables the strobes, U15 and U14A,
placing new ECG data onto memory bus. It also provides the write signal to the
RAM, U9. At this point, new ECG data is written into memory.
2.3.5.4
Delay ECG Gate (1026 count)
The oldest data in memory will be updated next and is located in the next cell
after the one which is being written into. The write signal (1025) is input to the
D flip-flop U11B and is tranferred at the next occurance of phase 3, to create the
write +1 signal (1026).
It is used to sample the oldest signal out of memory for
the recorder and EXTERNAL ECG.
2-19
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
© 01 >
CLK RESET
3
r
0
/^ii
(D
©
D
U5A.6A.7A
1025 PULSE
0
Q
®
••1026
PULSE
UIIB
UNA
01 >
D
01 >
CLK
CLK
1025 COUNTER
CHAIN
01
©
1024 OUTPUT
©
1025 PULSE
©
1026 PULSE
-WRITE SIGNAL
Figure 2-21
2.3.5.5
Address Counter
A 10 stage binary counter is formed by U5A, U6A and U7A. The counter outputs go to
the address inputs of the RAM.
The counter sequentially steps through the
addresses from 0 through 1023, then repeats.
The binary counter is incremented by
Phase 1.
Each address is held for 4 micro- seconds.
2.3.5.6
RAM Read-Write
To read data out of memory, the R/W input
is a logic high and the chip enable (CE)
is a logic low. Data will be stored in the memory cell being addressed if the R/W
and CE inputs are both low. When the CE line is a logic high, the data lines
become tristate (high impedance).
2.3.5.7
Bidirectional Data Bus
ECG information, from the ECG amplifier board is placed on the data bus by the data
strobes U14A and U15A. The RAM, U9, receives and gives back stored information to
the data bus. This information is applied to the digital to analog converter U13.
2.3.5.8
Digital to Analog Converter (D/A)
The D/A is a
analog
circuit element which converts digital data from the
signal to the vertical
output jack.
The D/A
deflection amplifiers,
translates 256
possible combinations
(8 bit
current of zero to 0.8 mi Hi amperes. The operational amplifier,
this current to a voltage of zero to 3.4 volts.
2.3.5.9
data bus, to an
the recorder
and the
data), to
ECG
a
U17D, converts
Sample and Hold (Figure 2-22)
These circuits are composed of a MOS transmission gate and a capacitor. U14B and
C7 is the recorder sample/hold while U14C and C9 are in the CRT circuit. During
2-20
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
f^ hase
3 timing signal, the voltage output of the D/A circuit is passed through the
ransmission gates and stored on the capacitors.
MEMORY
D/A
CURRENT
TO VOLTAGE S/H
CONVERTER .„4r
UI7D
U9
MUX
UI6
U C
-vw-
,N
UI3
-vw
TO VERT
AMP
V
Figure 2-22 A
MEMORY
D/A
CURRENT
TO VOLTAGE c/u
AA/V-
CONVERTER J[M
BUFFER
T
•-VW
rcu
V
\
ECG
/
OUTPUT
LO PASS
FILTER
OUTPUT TO RECORDER
1025 OR
1026 PULSE
Figure 2-22B
2.3.5.10
Ramp Generator (Figure 2-23)
The ramp generator produces a modified sawtooth waveform for horizontal deflection.
U17C is the ramp generator switched by comparator U17B. When the comparator output
is high, Cll and C12 charge through R20 to produce a rising ramp voltage. At the
end of 4 milliseconds, the comparator output switches negative which rapidly
discharges
the capacitors
through
CR5, moving
the beam
back toward the
Timing for the ramp generator originates with the 1025 counter or the
counter, depending on the position of the FIXED-MOVING trace switch.
_
_
.
left.
address
R20
_n_n_ >~r^ww
CR5
DISCHARGE
THRU CR5
-w:cn
CHARGE THRU
R2I
R20.R2I
[CI2
V
Figure 2-23
:.3.5.n
Analog Multiplexer (MUX) (Figure 2-24)
The analog multiplexer, U16, alternately switches between ECG and HEART RATE digits
as a source for the vertical, horizontal and intensity information.
The ECG source
2-21
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
is on for 4ms and the HR digits are connected for the next 12ms.
(The recorder
microprocessor only uses about 4 ms to place digits on the CRT and the remaining
time the CRT intensity and deflection are off.)
MUX
UI6
° V
ADDRESS >
©
CLK
SELECT
COUNTER
3L_
JZ
"It,
UIOC
—*> (|) RAMP GENERATOR SYNC SIGNAL
©i
i
i
i
i
®i
Figure 2-24
2.3.6
Deflection Board 78660-60180 (Refer to Figure 6-6 for detailed schematic)
This board provides the drive signal for the CRT and deflection yoke,
a vertical amplifier, a horizontal amplifier and an intensity driver.
2.3.6.1
It contains
Vertical Amplifier.
The vertical signal is applied to a bifet opamp through the gain adjustment
potentiometer and a phase lead network. The purpose of the phase lead network is
to emphasize the higher frequency signals.
The opamp drives complementary
preamplifier transistors Q2 and Q3, which in turn drive complementary output
transistors Q4 and Q5. The output transistors apply +16 or -16v to the deflection
yoke. Current through the yoke flows through R13 to ground, producing a voltage
which is fed back to the inverting input of the opamp. When an input signal, say
lv is applied to the opamp, the output of the opamp goes to the plus rail, +12v,
turning on the positive amplifiers, applying 16 volts to the yoke. The current in
the yoke will increase slowly since it is primarily inductive. When the current
across R13 to reach lv, the opamp output will be reduced to a
It is this negative
level
sufficient to maintain that current in the yoke.
beam
(which
is
deflected
proportionately
to current
feedback which causes the CRT
the
input
voltage.
(Refer
to
Figure
2-25)
in the yoke) to closely follow
causes the voltage
OP AMP
POWER AMP
>
Figure 2-25
2-22
/m^
j
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-1
The purpose of Ql is to modify the point at which the positive and
amplifiers turn off and thus serves to eliminate crossover distortion.
2.3.6.2
negative
Horizontal Amplifier
The horizontal amplifier operates exactly the same as the vertical except it has no
phase lead network or preamplifers. Capacitors C2,3,and 4 aid in ellimi nation of
crossover distortion.
2.3.6.3
Intensity Driver (Figure 2-26)
The purpose of the intensity driver is to bias the CRT
desired by the operator per the INTENSITY potentiometer.
+ I2V
to the
intensity level
^7
6-I2V
+ I2V
MIN INTENSITY
~40V
MAX INTENSITY I£
AA\—i + 200V*—Wv-
V
J^
-AAA/-
^
I INTENSITY
V
Figure 2-26
It also turns off the beam when necessary such as between digits, during the erase
bar, during retrace of the horizontal beam, and during periods in between
displaying the ECG signal and the digits signal.
(Refer to Figure 2-27).
+ I2V
BLANKING SIGNAL
-I6V
-I5V
H4-
AAA,
2.5V -
'40V
+ 200V -«—WV
-AAAr-
^7
Figure 2-27
r
The intensity information from the MEMORY PCA enters the board at logic levels 0 to
+5 volts and is changed by opamp Ulb to levels of -16 to +12 volts. The input of
opamp U1C receives intensity signals (within 1 diode drop) of -16 volts to between
0 and +12 volts depending on the setting of the intensity controls.
2-23
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3.7
•^k
Clock/Heart Rate Board 78660-60260
(Refer to Figure 6-7 for detailed schematic)
This board generates the heart rate digits displayed on the monitor CRT and
contains the clock circuit that keeps time for the recorder print out. Additional
circuits include heart
speaker driver.
2.3.7.1
rate
alarm switch
and service
switch
sense, and
alarm
Heart Rate Circuit (Refer to Figure 2-28)
The R-wave pulses, from the ECG digital board, are counted by the recorder control
microprocessor to calculate the heart rate and generate the horizontal and vertical
digital codes, which are passed to the I/O expander Ul, on the clock/heart rate
board.
2.3.7.2
Heart Rate Digital Display
D/A converters, U2 and U3, produce the horizontal and vertical components that make
up the heart rate numerals displayed on the CRT, with U4A and U4B acting as unity
gain buffer amplifiers.
Intensity information comes directly from the I/O
expander, Ul.
2.3.7.3
Language Option Selector
The dip switch array, A7S1, is used to select documentation
by the recorder, and real time clock.
2.3.7.4
and language, printed
Heart Rate Alarm Switch
When the alarm switch is on, Ul will enable the gates U5a, b, and c if the heart
rate is outside the limits. The beeper signal is then passed on to the speaker
driver transistor Ql.
SERVICE
SW
ALARM SW
vv /
PI2
?
FROM
RECORDER
CNTL BD
A8
£
U2
D/A
-> 3 HORIZONTAL
Ul
I/O
EXPANDER
£
U3
D/A
-> 4 VERTICAL
INTENSITY
"^ 5 BLANKING
NG
ALARM CNTL
E
DIP SW
^y\
JL SPKR
SI
500Hz INPUT
FROM MEMORY BD
Figure 2-28
2-24
~\
>
TO MEMORY
BD A5
^%
SECTION II - THEOR Y OF OPERA T10N
Models 78670A/786 71A
78670A-1
2.3.7.5
Clock Circuit (Refer to Figure 2-29)
U7 is a CMOS calendar/clock integrated circuit. This circuit keeps track of
months, days, hours, minutes and seconds, and supplies this information to the
recorder control microprocessor. This data is passed on to the recorder board on
power up and once each hour on the hour when the instrument power is on. Between
updates
the recorder
control
microprocessor keeps track
of
time
and date
in
software.
The chip select signal calls up Ul or U6.
To read the clock, U6 is selected.
CLOCK DISABLE
U6
FROM
RECORDER
60 A3
*
I/O
EXPANDER
S^JH-
Q—
-> H SLEEP
-)lO V RAW
Figure2-29
U6 then outputs a low on pin 22, the clock disable line. The collector of Q2 goes
high approximately 100 msec later, having been delayed 2 times the time constant of
R28 and C18. The + input of U8 (a CMOS comparator) then is at about 2.6 volts, and
its output goes high enabling the clock chip. This signal is fed back through Q6
and U6 to the recorder control microprocessor telling it that the clock is ready
for data input or output (time set or read).
During a clock read the output of U8
will be high approximately 20 msec (Figure 2-30).
+5
A
0
^^\
B
+ 5
0
+ 2.6V
c
0
inn m^
P
\
•— 20 mS
Figure 2-30
jf^K
The clock accepts parallel commands over three lines, C2,C1, and CO.
These are
pins 1,2, and 3. The commands are strobed in by pulses on pin 4. The data are
shifted in on pin 6 (time set) and out on pin 9 (time read). The shift clock is on
pin 8.
2-25
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-1
The clock's oscillator frequency can be checked at test point TPl, which should be
2048.00 Hz.
On a read cycle (time read) there are four commands executed:
(See figure 2-31)
C2 CI CO
1 1 0
Oil
TP=2048 Hz
time read
0
0
register shift
register hold
0
0
1
0
1
test point frequency set
time is parallel loaded into internal
shift register
allows shifting out of data
holds shift register,shift clock
i gnored
1
1
1
1
1
1
1
1
~|
STB
o
i
C2
|
|
iJ i
CO
40 PULSES
nnnnnnnnnnnnn
CLK
O
1
u uu uuu miss?-™
DATA OUT
O
1
DATA IN
Figure 2-31
On a write (time set) cycle there are three commands executed: See figure 2-32
C2 CI CO
0
0
0
10
1
time set
register shift
0
0
register hold
allows shifting in of new data
new time /date information is parallel
loaded into internal counters
0
holds shift register, shift clock
ignored
1
(—
STB
C2
1
i
!
O
CI
CO
O
"L
j
i
1
'
40 PULSES
CLK
nnnnnnnnnnnnn
1
DATA OUT
O
1
DATA IN
0
| | | | | 11|
|| DATA OUT IGNORED
|| | | [| [ | || DATA SHIFTED IN
Figure 2-32
2-26
1
7
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-2
After a write cycle is finished a read cycle is executed.
pushing the PUSH TO MARK button the new time and date can
By
be checked.
2.3.7.6
Voltage Reference
U9 is a precision temperature compensated voltage regulator which furnishes a 2.490
volt reference voltage to the comparator U8. This reference is compared with a
fraction of the +5 volt supply to detect power failure and disable the the clock.
This reference operates at all times from unswitched raw system battery power. The
current drain is about 1 milliampere, which is less than the self discharge rate of
the nickel-cadmium battery.
2.3.7.7
Clock Battery
The clock chip, U7, is powered by a small battery
Clock/Heart Rate Board. Since the clock is independent
it keeps time when those sources are removed. The clock
microamperes, so the battery life should equal the rated
2.3.7.8
which is located on the
of external power sources,
chip current is only a few
shelf life of the battery.
Clock Protection
A low on the sleep line causes the collector of Q2 to go low which
clock during the defibrilator discharge (Figure 2-29).
j#*N
2.3.7.9
disables the
Clock Crystal
A quartz crystal, operating at 32.768 KHz, maintains the accuracy of the clock.
Typical accuracy of the clock is 5 minutes per month, plus adjustment tolerance
over the temperature range of 0 to 50 degree C.
At a reasonably constant room
temperature, accuracy is about 5 minutes per year.
2.3.8
Recorder Control Board 78670-60200
(Refer to Figure 6-8 for detailed schematic)
This board controls the operation of the recorder, annotation, and calculation and
display of heart rate. The recorder functions include chart drive motor and sylus
heat control, ECG signal amplitude limiting and switching, and print head drive.
2.3.8.1
The ECG
ECG Monitor to Recorder Signal
signal to
the recorder is
buffered by a unity gain
inverting amplifier
composed of U5a, R10, and Rll. To prevent the recorder stylus from moving when the
recorder is turned off, the signal is switched by Q5. When Q5 is on the gain of
the amplifier is reduced to a very small value (<<1) and essentially no signal is
passed (see Figure 2-33).
2.3.8.2
r
ECG Memory to Recorder Signal
The ECG signal from the memory board to the recorder board has a DC offset of about
2.56 volts. This is cancelled to approximately zero by the circuit consisting of
CR12, R43, and R44 (figure 2-33).
2-27
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-1
2.3.8.3
Recorder Movement and Stylus Heat Control
The recorder chart movement and stylus heat are controlled by a signal at edge pin
1. A high here (>2.5 volts) turns the chart drive and stylus heat off, and a low
(0 volts) turns them on. These signals are controlled by microprocessor Ul,
through Q3 and Q4.
2.3.8.4
Recorder/Signal Control
A high (+BAT) at the collector of Q4 turns the recorder off, and Q5 on, to prevent
signal transmission. A low (-5 volts) at the collector of Q4, turns the recorder
on and Q5 off, allowing signal to pass through to the recorder stylus deflection
circuitry.
(^CRI2
ECG TO RECORDER
U5A
-I2V
R43
R44
-wv-
-vw-
56V
RIO
RM
ECG IN
Q5
®
CR7
R42
-WSW BAT
Q4
RI7
a/w
>R\A
•RI3
f_Q3
•
7<^\
R4|
-vw-
Ul
19
CR8
TO RECORDER
!ECR5
-I2V
V
Figure 2-33
2.3.8.5
ECG Signal Ampltude Limiting and Switching
To prevent excess power consumption in the recorder stylus deflection circuits, an
active limiting circuit is employed to prevent overdrive of the recorder input.
This circuit is composed of Q1,Q2,CR2,CR3, and R4 through R9. In normal operation,
Ql and Q2 are biased off. However, when the output signal excursion is greater
than approximately + or - 2.1 volts, Ql or Q2 turns on, drastically increasing the
negative feedback and reducing the gain of the amplifier (Figure 2-34).
The effect
of this is to limit the output signal excursion to + or - 2.1 volts. CR2 and CR3
prevent reverse bias breakdown of the base-emitter junctions of Ql and Q2.
+ I2V
ECG SIGNAL
Rl
IN
ECG OUT
TO RECORDER
Figure 2-34
2-28
SECTION II - THEOR Y OF OPERA TION
Models 78670Aj78671A
78670A-1
^
2.3.8.6
Microprocessor Reset (Tickle) Circuit
A defibrillator is a very high noise environment. The noise impulses produced by
the defibrillating pulse and the associated high voltage relays can cause the
recorder control microprocessor operation to be disrupted. To prevent this, a
circuit known as a "tickle" or "heartbeat"
circuit is used.
It is a retriggerable
oscillator which is retriggered at periodic intervals by a software routine in the
microprocessor.
If noise causes program disruption and the failure of the
microprocessor to retrigger the circuit, after 20 to 25 milliseconds the tickle
circuit will force a reset of the recorder control microprocessor.
This circuit consist of U5b, Q6, Q7 and
2-35). The circuit operation is similar
(figure 2-36).
The two series gates are
non-inverting input, and the third gate by
associated passive components (figure
to that of the three gate oscillator
simulated by the op-amp U5b using its
Q6 operating as an inverting amplifier.
+ 5V
SLEEP
R26
-I2V
WV
1)
W.
JCR4
-I2vJ L
TICKLE PULSE
IN
R24
€
R23
R22
R36
•
WV
?R27
R20
it—<WV
•
CRII
-w-
+ 5V
07
12V
RESET PULSE TO
MICROPROCESSOR Ul
Figure 2-35
Figure 2-36
When allowed to free run (no retrigger signal from microprocessor) the "tickle"
circuit produces a series of negative going pulses approximately 1 millisecond wide
(figure 2-37) with a period of 20 to 25 milliseconds.
1111
1111
1111
1
1
VERT.
1.0 V/Div.
HORIZ.
5 ms/Div.
Figure 2-37
2-29
SECTION II - THEOR Y OF OPERA TION
Models 78670Ap8671A
78670A-l
To "tickle" or retrigger the circuit, a pulse about 1 millisecond wide is generated
by the
microprocessor Ul, which
(collector of Q6) to
turns on Q7, charges
a high or non-reset state.
CIO, and forces
These
the output
pulses are generated every
16 milliseconds during normal operation of the instrument.
Cll forces a reset, on powering up the instrument, by pulling down on the inverting
terminal of U5b, forcing its output high and turning on Q6.
Q8 allows an external signal from the defib control microprocessor to reset the
recorder control microprocessor and put it to "sleep" during defibrillator
discharge for additional noise protection.
2.3.8.7
Print Head Driver
The printhead consists of 7 resistors with one common terminal, and a nominal
resistance of 87.5 ohms. The printhead is bonded to a flex cable one end of which
inserts into a connector (J30) on the the recorder control board.
The common terminal is connected to the positive volt power supply through
protective circuitry.
The Darlington transistor array U2 sinks current through
each resistor to heat it and produce a dot on thermally sensitive paper (figure
2-38). U2 is driven in turn by CMOS gates U3 and U4. One input of each of seven
gates are tied together to the output of the eighth gate through a network
consisting of C1,R1,R2, R3, and CR1. The seven gates act as signal switches for
the printhead drive signals coming from Ul. The RCD network prevents the printhead
from being enabled longer than 3-5 milliseconds.
This is to protect the printhead
in the event of a microprocessor failure. The inputs are biased up to +4 volts by
R2 and R3. A negative going edge at pin 11 of U4 causes the seven gates to be
enabled for a length of time controlled by the time constant of CI and the parallel
combination of R2 and R3. The diode allows quick charging of CI on positive going
edges. Rl is to limit capacitive current.
MICROPROCESSOR
DARLINGTON
ARRAY
CMOS GATES
THERMAL
PRINTHEAD
—o—wv—i
£>
-(MMrHi
U3
Ul
f—- +5V
U4
R3 2LXR4
£>
V1
Rl
-KCI
:R2
PRINTHEAD
PROTECTION
NETWORK Q9,
QIO
TO +I5V
I—• TO Q7 AND TICKLE CKT
Figure 2-38
The output
pin 11 of U4
also drives Q7 to retrigger the "tickle"
above)
The drive signal to U2 is shown in Figure 2-39.
2-30
circuit (see
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-1
h
++++ •ffH
4+H fH4
r\
H-H :i+H
Hff •+++
VERT.
1.0 V/Div.
HORIZ.
5 ms/Div.
Figure 2-39
2.3.8.8
Print Head Protective Circuit
Q9, QIO and associated components protect the print head from power up and power
down transients. On power up, C21 clamps the Q9 base to -12 volts, holding it off.
C21 slowly charges through R47 until Q9 turns on which turns on QIO, applying power
to the print head. On power down, the +5 volts decays rapidly, forward biasing
CR15, which forms a capacitive voltage divider of C20 and C21. This decaying
voltage turns off Q9 and QIO, removing voltage from the print head (Figure 2-40).
+ I5V
+ 5V
CRI5 n?
jp\
I
.QIO
5
R46
51.1K
PM
C22
330/xF
TO PRINTHEAD
DRIVER U2
PRINT
HEAD
C20
33/xF'
♦ -I2V
Figure 2-40
2.3.8.9
Input/Output Lines
See the detail schematic (Figure 6-8) for the following circuits.
Ul lines P10 thru P13 (pins 27 thru 30) go to the defibrillator
control board.
Information to be printed is passed to Ul over these lines. The data available
signal from the defib control board generates an interrupt which signals Ul that a
message is available.
PROG,
P20 through
P23 (Ul,
lines 21 through 25)
expanders, Ul and U6, on the clock board.
the I/O expanders is selected.
communicate with
The chip select
The 16 millisecond line comes from the memory
the two
I/O
line controls which of
board and is used to synchronize the
printing and the CRT display.
The R-wave line comes from the ECG digital board. Ul counts R-wave
calculates heart rate which is printed and displayed on the CRT.
The TAP line
For ewery
(Ul, pin 33) goes
time the
to the PUSH 8 SEC RUN switch on
switch is actuated
the recorder
will run 8
pulses and
the front panel.
seconds up
to a
maximum of 60 seconds.
The MARK line (Ul, pin 32) goes to the PUSH TO MARK switch.
tells Ul to run the recorder and print
Closure of this switch
a down arrow and the time/date information.
2-31
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
The RUN line (Ul, pin 31) goes to the
RECORDER switch.
It tells Ul to turn on the
recorder.
The SERVICE line (Ul,pin 37) goes to the SERVICE switch.
It is used in conjunction
with the PUSH TO MARK switch to enter the time/date set mode.
This mode is entered
if while the PUSH TO MARK switch is held down and the power is off, the power is
turned on and approximately 1 second later the SERVICE switch is pushed or pulled.
2.3.9
Defibrillator Control Circuit Board 78670-60195
The defibrillator control board contains an 8051 microprocessor, a digital I/O
expander, LCD drivers, a "tickle" reset circuit, the chopper for the paddle contact
signal, transistor drivers for the low battery LED and charge done tone, an analog
multiplexer and an A/D converter.
2.3.9.1
Microprocessor
The 8051 uP is the heart of this board.
It is directly or indirectly tied to
everything on the board.
The main loop of software is executed every 4 mS, the 4
mS being generated by an internal timer.
2.3.9.2
"Tickel" Reset Circuit
U6, Q3, and associated components make up the "tickle" reset circuit. See Fig. 2-41.
TICKLES COME
4mS APART
UIO-7
n
n
U6-2
U4-1
P/OJ17
PINK
U6-3
DISCHARGE SWITCH
PATIENT RELAY DRIVER
MECHANICAL
DELAY OF
RELAY
RESET
PEAK CURRENT
P/OJ17
PIN H
•CURRENT THRU PATIENT
I PEAK
RELAY ACTUALLY
CLOSED
Zu.
-o
So
O
•=*80mSHIGH ELECTRICAL NOISE
PERIOD
UJ
II
o
Is*
Ooc
o">i-
OCI-
wocco
13
HO
S
->o
•"DLL!
"ZO
O CO
-ILL)
III.
wO
(OXLU
31-oc
Figure 2-41
2-32
•30mS
OF JUST
TICKLING
<
LU
U
CL
fC
o
<
LU
O
o
LU
CC
<r o
n
ii
/19%I
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
U6 is configured as a free running oscillator which would reset
80-100 mS, if not inhibited. When the uP is running properly, a
delivered from PI.6 (U10, Pin 7) every 4 mS to prevent U6 from
noise spikes upset the uP so as to reset the uP and start it
the uP once every
"tickle" pulse is
oscillating. If
running again at
propram address location 0.
When the uP closes the high voltage relays, it has also been programmed to stop
tickling, and U6 will then hold the uP in reset for the duration of high electrical
interference, thus increasing the immunity of internal registers. When the uP is
reset, the I/O expander (U4) is also de-selected and U5F will send a sleep* signal
to reset the recorder uP on the recorder board.
2.3.9.3
LCD drivers and recorder data
U7, U8 and U9 are CMOS BCD to 7 segments latch/decoder/drivers.
BCD data are put
out by the uP port 0 bits 0-3 (UIO, pins 36-39). Port 1 bits 0-2 (UIO,pins 1-3)
strobe the data into the LCD drivers.
If information is to be sent to the recorder
board, the DATA AVAILABLE* signal is used to inform the recorder uP that data is
ready. Since inverter buffers are used (U5A, B, C, and D), the BCD data are
inverted for the recorder uP whenever DATA AVAILABLE* is low.
See Fig. 2-42for
timing.
P0.0-P0.3
DATA
INVERTED
CODE
100's
INVERTED
100's
10's
INVERTED
NTs
Vs
INVERTED
1's
P1.3
DATA
AVAILABLE
P1.2
LCD 2
STB
P1.1
LCD1
STB
P1.0
LCDO
STB
^n
Figure 2-42
2-33
SECTION II - THEOR Y OF OPERA TION
Models 78670A\78671A
78670A-l
2.3.9.4
Analog Multiplexer and A/D Converter
U12 is an 8 to 1 analog multiplexer. P2.0 - P2.2 of the uP (UIO, pins 21-23)
select the analog signal to be sampled. Ull is an 8 bit successive approximation
A/D converter. R37 and C18 set the clock speed for the converter at about 300 kHz.
After an analog signal is selected, A/D conversion is initiated by a WR* signal
from UIO pin 16. When the conversion is completed, an interrupt is issued by Ull.
The uP services this interrupt by sending a RD* signal (UIO, pin 17), which clears
the interrupt request and brings the 8 bits of data to the bus of the converter.
The bus is normally in tri-state except when RD* is low. U13B, placed between the
multiplexer and A/D converter, serves as a unity gain buffer when Q5 is on, or, if
the analog signal is low and Q5 is off, as a 4x gain stage. The gain is controlled
by P2.3 of the uP (UIO, pin 24).
UlA is
an open drain CMOS buffer which acts as a
level shifter so that in the high state, the gate of Q5 can be pulled up to +12V by
R30. R53, R64, CR12, and CR13 protect U13B and Ull from over-current.
2.3.9.5
I/O Expander
The I/O expander, U4, expands the number of I/O lines which the uP controls. The
expanded ports are labelled P4 through P7 and each port is 4 bits wide. There are
4 instructions that it recognizes; write to port, OR with port, AND with port, and
read from port. An instruction and port selection from uP are latched into U4 on
the falling
edge of a strobe, PI.7 of the uP (UIO,
pin 8); data
is transferred
to/from U4 on the rising edge.
P4-P6 are input ports; P7 is output. P4 senses the front panel SYNC/DEFIB switch
and R-wave from the ECG DIGITAL board (RSYNC*) for conversion. P5 takes the input
from the charge switch, discharge switches, internal/ external* paddle selection
(ie, 50 J interlock), and the reed switch which senses when the paddles are in the
pockets.
P6 reads
the binary position of
the energy select switch.
P7 controls
the CHARGE DONE LED, patient relay driver and safety relay driver.
2.3.9.6
Relay drivers
The safety and patient relay drivers on this board, composed of U1D, U1E, Ql and
associated R's and C's, are only the intermediate stages between the controlling
I/O port and their respective transistor driver on the HV CHARGER board.
At
discharge, it is desirable to have the safety relay lag behind the patient relay so
that most of the energy is dissipated into the patient and virtually none into the
10K ohm safety resistor.
The commands from the uP to close both relays are given
simultaneously. After the commands are given, the uP is reset and it must be the
hardware (R23, C16, and CMOS input of U1E) which delays the safety relay.
2.3.9.7
Charge Done Tone
Q2, R24, Cll and CR3 form the speaker driver. The signal going to the base of Q2
is shown in Fig. 2-43. The fundamental frequency is 250 Hz. Therefore, to the ear,
the tone sounds different
from the R-wave tone or the heart
rate alarm tone, both
of which emphasize the harmonics of roughly 500 Hz.
2.3.9.8
Battery LED driver
Q4 sinks the BATTERY LED current. When the battery is being charged, Q4 is turned
on continuously with base current being supplied through R28. When the battery is
low (SwBatt 2 is sensed by uP) and is not being charged, the uP flashes Q4 via CR5
with a 1 second signal of 33% duty cycle.
2-34
SECTION II - THEORY OF OPERATION
Models 78670AJ78671A
78670A-1
LED NO. 10 THRESHOLD
CASE 2 LED NO. 7
—
LED NO. 9 THRESHOLD
ON TIME
LED NO. 8 THRESHOLD
"=-
LED NO. 7 THRESHOLD
LED NO. 6 THRESHOLD
^ASE2
^-
CASE1 LED NO. 71
2.3.9.9
LED NO. 5 THRESHOLD
ON TIME
F
LED NO. 4 THRESHOLD
The paddle"
indicates
means lower
LED NO. 3 THRESHOLD
and ampliff
display loc
stable.
LED NO. 2 THRESHOLD
Here's how
A
LED NO. 1 THRESHOLD
very sh(
discharges
through R4<
chopped vo
comparators
up only on
a smal1 ch c.
n AA
one whole F,9ure2-44
display ha
f^
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-2
2.3.9.10
Monitoring the HV capacitor
Figure 2-45 shows a simplified schematic of the HV capacitor monitoring circuit. As
the capacitor is being charged, the current flowing through the 24.9M resistors on
the HV charger board, will keep the capacitor balanced around 2.7 volts. At the
same time, U1D increases in voltage (referenced to ground) and U1C decreases by the
same amount (but with reference to 5.4 volts). On the control board, U13A inverts
the signal from U1C so that, at the input to the multiplexer, both signals will be
of the same polarity and increasing with respect to ground. Thus the numerical sum
of these two signals will indicate the voltage on the capacitor, even if the
capacitor is imbalanced by some stray resistance to ground on one side.
R72
|—VVV
»- +2.!
+ 2.5V
^L
Q Energy
V
Adj
24.9M
FROM FLYBACK
TRANSFORMER
-VW-
TO
A/D
5.4V <
CONVERTER
32 uF
HV CAP
8 TO I
MUX
UI2
24.9M
V
UID^> \
>^
—VW—*—\y^
>
*STRAY
I
36 K
vvv
'
V
HV CHARGER BOARD
CONTROL BOARD
Figure 2-45
Energy
Adjust
Pot (R72) is an adjustment made to correct for the
HV capacitor
tolerance.
2.3.9.11
Charge and Discharge Cycle
A defibrillation episode
is initiated by pressing and releasing
(a high and then low at U4 pin 22).
the charge switch
The uP then reads the (UIO pin 6) low to start
the charger circuit.
When the capacitor voltage reaches its selected value,
SHUTDOWN will go high and will periodically go low to keep the capacitor voltage as
close to the set value as possible. If the energy select switch is changed before
2-37
SECTION II - THEOR Y OF OPERA TION
Models 78670Aj78671A
78670A-l
the capacitor
is discharged, the uP will charge to the new setting,
dumping the
capacitor into the safety resistor if necessary.
When the proper capacitor voltage
is reached,
the charge done tone will
be
activated. The charge done LED is turned on (U4 pin 13 goes low), and the uP now
looks for a high on U4 pin 1. A high means both discharge switches have been
pressed simultaneously. When the high is detected, the uP will turn on the patient
relay driver and turn off the safety relay driver (i.e., close both relays) and
wait for reset
as described in Section 2.3.9.2.
The only exception is
cardioversion or synchronized defibrillation.
2.3.9.12
Cardioversion
For cardioversion, everything in the charge and discharge sequence is the same
except the relay drivers now are closed only on a high to low transition of RSYNC*.
The sync mode is selected or de-selected by a switch on the front panel which
momentarily grounds SYNC ON* or DEFIB ON* respectively. This switch information is
sensed by the uP through U4 pins 2 and 3. Sync mode may not be selected unless the
monitor is picking up the ECG from
leads instead of the paddles.
This
LEADS/PADDLES* signal from the ECG ANALOG board comes to the uP at UIO pin 27. The
uP tells the ECG DIGITAL board of sync mode through SYNC EN* (UIO pin 25). The ECG
uP responds by pulling RSYNC* high. When RSYNC* is high, the sync LED on the front
panel is turned on by U1F.
On each
detected R-wave, RSYNC* goes low for about 200
mS and the LED is turned off for that time period.
2.3.9.13
Software Safety Features
The software in
the uP monitors for certain
failures in the HV
cirucits and will
disable the charge and discharge cycle if an unsafe condition is detected. Some of
the problems it looks for are: overcharge, HV capacitor grounded, leaky capacitor,
safety relay failed to open or close, arc in patient relay, and certain reference
voltages out of specifications.
2.3.10
Defibrillator High Voltage Section
(Refer to Figure 6-11 for detailed schematic)
2.3.10.1
General
This section describes the following:
1.
Defibrillator paddle set, with CHARGE and DISCHARGE switch.
2.
HV defibrillator inverter power supply PCB 78670-60120.
3.
HV defibrillator energy storage capacitor.
4.
HV patient relay and drive circuit.
5.
Discharge current transformer and sample/hold circuit.
6.
HV safety relay and drive circuit.
7.
Voltage reference/low battery shutdown circuit.
2-38
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3.10.2
Power Circuits
The HV defibrillator inverter PCB contains power circuit wiring, between the
battery, Power Base and the mother PCB. The battery connects to J43 and J44; the
Power Base at J45 through J48.
V-REG from the Power Base closes relay Kl,
supplying V-REG to the mother PCB and V-RAW to the HV flyback transformer/drive
circuit. CR114 guarantees Kl coil dropout for Power Base AC loss, reconnecting the
battery to all power circuits. C17 and C19 suppress noise. Battery charge current
(J48) flow through CR9 and R129 to the battery. The Q22 circuit gives steady
lighting of the front panel BATTERY LED if both charging voltage and battery are
present.
Switched
voltage Vc,
returns to this PCB
via
J19, pin
17, for
all low
level
circuits.
NOTE: Power
connects to Tl
via A11F1 at all
times, unless both
battery and
Power Base are removed or A11F1 open.
2.3.11
Pulse Width Modulator (Figure 2-46)
U3 is an I.C.
Pulse Width Modulator (PWM), including a +5 volt regulator circuit
for power to I.C. circuits, with pin 16 for external use. Cll and R31 set the
oscillator frequency at about 8 kHz. This supplies a sawtooth drive to the
internal comparator and gating to the internal flip-flop, which enables the gates,
ensuring the output transistors are never both on at the same time.
The other comparator input, pin 9, controls the duty cycle, (nominal 1.0 volt off
and 3.5 volt maximum). The output can be reduced or shut down by (1) pulling down
on pin 9; (2) applying a positive voltage to pin 10; (3) if pin 1, error amplifier,
pulls above the pin 2 reference of 2.5 volts, or (4) if pin 4, current limit
circuit, rises above the nominal 200 millivolt cutoff.
CR4 limits pin 9 maximum
voltage, to give a nominal 90% maximum duty cycle.
R27
^'^
"cO^i—Hi
r
Cll
-I-.OI
let
15
<R3I
>I4 7K
Jri _NC
AAAA^
vc
OSC
On?
+ 5V
REF OUT
TP9
OUTPUT
o
<§>•
R26
IOK
HV
LIMIT
OUTPUT
^C>JT^LTlN
V REG
-*• +5V
Error Amp
FLYBACK
DRIVE
CURRENT
LIMIT
COMPARATOR
^jtLsy—^L__p>
i
R25
IOK
f—jmruL
CURRENT
LIMIT
U3
SELECT 3524
I
Tb
CR4
—14SHUTDOWN
INPUTS
Figure 2-46
2-39
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-2
2.3.11.1
PWM Shutdown (Figure 2-47)
This circuit acts as
a soft-start ON/OFF switch for the PWM, U3, discussed above.
Pin 8, J19 connects to UIO, pin 6 in the Defibrillator Control PCB. This is open
circuit when not charging the defibrillator capacitor, so the base of Q9 is pulled
up with current flowing from Vc through R48, CR13 and CRll. Q9 clamps pin 9, U3 to
ground through the Schottky diode CR111, keeping U3 shut down. The PWM is selected
for guaranteed minimum cutoff voltage of 0.7V.
2.3.11.2
Soft Start
The defibrillator HV capacitor charge cycle is started by pressing the APEX paddle
CHARGE switch S10, which connects+5Vto the defibrillator control PCB. The control
microprocessor clamps the voltage at pin 8, J19 to about 0.5 volt. CR13 and CRll
provide sufficient drop to assure Q9 turnoff. COMP current then flows from U3, pin
9 through CR111 and R121 to charge C105, giving a startup time constant of about
1/3 second - important for accurate low energy selections. C8 inhibits PWM restart
during the OFF part of the duty cycle, while under current limit control.
CR112 normally gives enough drop so the shutdown circuit, U3, pin 10 is not
activated, but will operate if the Q9 circuit open circuits, but without Soft
Start. The Low Battery Shutdown circuit inhibits charge by pulling up on the base
of Q9.
TO SHUTDOWN
U3 PIN 10
FROM
LOW BAT
SHUTDOWN
TO COMP
U3 PIN 9
4
SOFT START
>CRII2
ZCRI
•RI06
CI05
C8
;cri3
J19
TO DEFIB
CONTROL
BD AIO
R48+!?y
•AAA/—<J>
ih +s°v
t CRI24
I
JI5
PI5
SIO
fcl
CHARGE
^3>
6f
L
I
APEX PADDLE
(RIGHT)
Figure 2-47
2.3.12
HV Defibrillator Inverter Circuit (Figure 2-48)
This circuit, driven by the Pulse Width Modulator (U3) output, provides
voltage to charge the defibrillator HV capacitor, Al-Cl.
2-40
the high
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-1
The
The
(or
Q5,
PWM "on" drive switches Q2 on, in turn switching on Q5, through C13 and R32.
primary of Tl thus starts a linear current ramp, with slope determined by V/raw
V/bat) and the Tl primary inductance. When U3 turns off, Ql abruptly turns off
producing the "flyback" high voltage discharge from the secondary of Tl. The
Tl primary tap provides sufficient turn-off bias
(across R32 and C13) for Q5.
CR5
and CR100 define safe voltage limits for Q2 and Q5.
The HV rectifier contains HV metering resistors, a rectifier diode and noise filter
capacitor. Note that two metering resistors define the ground point for the HV
defibrillator capacitor approximately midpoint between the 2 terminals voltages,
e.g., +2.6 kV and -2.6 kV nominal for the 360 joule charge condition.
The defibrillator HV energy storage capacitor (32 uF, 5.5 kV) is a compact,
long-life polyester (e.g., "Mylar ")' type component.
As is typical, it can
self-charge after operation, and must be short circuited during handling, for
safety. The usual failure mode is a dead short. HOWEVER, AN OPEN CIRCUIT INTERNAL
CONNECTION CAN OCCUR, WITH POSSIBLE REC0NNECTI0N, DURING HANDLING, AT LETHAL ENERGY
VALUES: KEEP A SHORTING WIRE ON THE TEMRINALS WHEN NOT IN THE CIRCUIT.
The actual duty cycle, during charging, is determined by the current limit circuit
in the PWM. It is adjusted by R34 , set for a charge time to 360 joules of 9
seconds with a fully charged battery, or 7 seconds with the Power Base, with the AC
line at 110 to 120 volts.
TP2
TPl
HV FLYBACK TRANSFORMER/RECTIFIER
TJ
i+J 5.5kV
CR5,
24.9M
m
CRIOO
CI6
+
-
TO HV
t*x^
METERING
6
AMPS
VRAW
FROM PWM DRIVE
U3 PINS II S 14
R35
TO PWM CURRENT
LIMIT PIN 4
rn
m
Figure 2-48
2.3.12.1
c
HV Monitor Circuit (Figure 2-49)
As the Inverter charges the defibrillator capacitor, the 24.9 M ohm metering
resistors provide positive drive to amplifier U1C and negative drive to amplifier
U1D. After inversion by these amplifiers, the "V-Cap 1" output will rise above
ground, while the "V-Cap 2" output will drop below the noise filtered (R140,c4)
2-41
SECTION II - THEOR Y OF OPERA TION
Models 78670A\78671A
78670A-l
55.4 V Ref.
as
the defibrillator capacitor is charged.
R141
and R142 connect to
the error amplifier (U3, pin 1).
Both the "V-Cap 1" and "V-Cap 2" provide
defibrillator cap voltage samples to the Defibrillator Control Board A/D converter,
where these determine the defibrillator "Charge" shutdown point, such that the
preset energy will be delivered to
a defibrillator energy meter, after adjustment.
The divided output of UID will turn off the PWM when the Error Amplifier Input, U3
pin 1, rises to 2.5 volts, limiting the high voltage to a nominal 6.3 kV.
C119
H
R139
U1D-;
-AAAr-
V-CAP 1 12^+2.5 V
=1141
["erroramp! ~] R^F-
V
'HV RECTI
U3
1
R142
9 COMP
MOTHER-io^-
BDGND.
N
+ CAP
C3
PWM
~HV
-DEFIB
ih
-vw
R6
^
V-CAP 1 74"
R140
uic\h=i
-V\Z\r-a 5.4 V REF.
C4
?
~>
Figure 2-49
2.3.12.2
Patient Relay Circuit (Figure 2-50)
The Patient Relay is a high current, high voltage pressurized D.P.D.T. relay. One
know end-of-life failure mode is "flashing", which may result in abrupt failure of
the pressurized glass envelope.
ALWAYS WEAR APPROVED GLASSES OR OTHER EYE
PROTECTION WHEN HANDLING OR WORKING AROUND THIS RELAY.
Discharge of the energy from the HV
Defibrillator Capacitor to the patient or test
load requires simultaneous closing of both paddle DISCHARGE switches. Vc, J16 1,
thus connects through the STERNUM paddle switch to 2, then to J15 2 through the
APEX paddle switch to 1. This provides required power to the Patient Relay and
turns on Q8, sending the DISCHARGE REQUEST signal to the Control PCB via J19, pin
15.
The Defibrillator Control
PCB originates the discharge command,
which lasts about
120 msec, through J19, pin 13. This high signal (1) opens circuit Q6 (Figure
2-51), preparing the I/pk sample/hold capacitor C2, and (2) drives Q3, activating
the Patient Relay.
If Q3 is driven on or shorted,
battery shutdown circuit, UIB.
U4B
prevents high
voltage charge
via the
low
Except when discharging, the patient relay connects the paddle electrodes to the
Analog
ECG PCB,
impedance circuit.
2-42
via
P26.
Coaxial
cables
minimize noise
pickup
on this
high
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
capacitor, a current
The discharge circuit
includes the HV defibrillator
This could
transformer, and an inductor to give the proper discharge waveform.
produces an intense pulsed field, giving a "bang" during discharge if the
A 50 ohm test load is
defibrillator is placed on any metal table top.
automatically connected when the paddles are locked in the upper case paddle
storage compartments.
APEX
PADDLE
(RIGHT)
^
JI9
INT/EXT SELECT.
1ELECT
14 <-o
o i
lT
EST
;dischg| j >'son
OISCHG
♦ 5 V REF
RI33
SELECT
LOAD
—ViA,
1
V
^2
N P24
Sf^
CR124
rh
JI6 s. 2 v. PI6
r1^ •>J-^
STERNUM
PADDLE
(LEFT)
w.--e-*<
MOTHER BD
6
DEFIB CAP
PADDLE ECG TO
ANALOG ECG BD
PATIENT RELAY
noiwc
N
VjukjkJ
'Pk
XFMR
J2l
r
•—W-±
~X
DEFIB
INDUCTOR
P2I
-4>">]
L>5
^
Figure 2-50
2.3.12.3
Peak Current Detector Circuit (Figure 2-51)
A HV discharge lead loops through the current transformer, A1T2, which has a 0.004
current output ratio.
This output drives the A13-R2, R3 and RIO load/voltage
divider. CR103 clips noise at the filtered (R138, C118) 5 V ref. level while CR2
clips negative spikes, R7, C103, R36 and C108 filter noise. U4A is an open
collector output, MOSFET input comparator. When the voltage input signal at U4A,
pin 3, is higher than the voltage on hold cap C2, the comparator output is high
(open collector off) and C2 is charged through R41 and CR1. When C2 is charged to
equal the input voltage, the comparator output goes low (open collector on),
reversing biasing CR1, and C2 holds the peak. C106 is AC positive feedback which
causes the comparator to switch quickly and prevents oscillation. In normal
operation, when the signal is rising (heading for peak), the output of U4A (pin 1)
will be high frequency
pulses (100's of kHz), whose amplitude tracks the input
signal.
JWs^
As mentioned in Section 2.3.12.2, C2 is reset except during the '120 msec discharge
0M pulse. Since it takes about 15 msec for the patient relay to close, Q6 is open
and C2 undamped when the current transformer output rise begins. The C2 hold time
allows adequate
time for
relay noise to
end and
defibrillator control
microprocessor reset prior to sampling.
2-43
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-2
Ipk RESET
>RI23
$ ^(fff
JI9
MOTHER BD GND 10 ^~
^7
I PEAK OUTPUT 9 ^-
021
c y
Peok Current
V
♦ SVREF^
| RI38
I
J. CRI03
cue
3
RI09 *
<RIIO
l
R36
;c2
[cios;
£
R7
o—Wv
J
RIO
IpK XFMR
*
:R3
;CI03 ACR2
?R2
V
Figure 2-51
2.3.12.4
Safety Relay Circuit (Figure 2-52)
This circuit connects a 10 K resistor, Al-Rl across the HV defibrillator capacitor,
except during the charging and hold period.
This safety resistor is under the
defibrilaltor inductor HV safety cover.
The S.P.S.T.
normally
closed HV vacuum safety
relay is shunted by
an R-C potted
snubber circuit, for improved contact life and noise suppression.
The Defibrillator Control PCB activates the relay drive at the start of a
defibrillator charge cycle by clamping pin 16, of J 19 to ground.
Q4 then turns
on, opening the safety relay. The safety relay is reclosed by the Defibrillator
Control PCB at:
a.
about 16 msec after Patient Relay is activated; or
b.
time out at about 30 seconds is not discharged; or
c.
when the ENERGY SELECT switch is turned to MONITOR or OFF; or
d. when the ENERGY SELECT switch setting is reduced with a charged HV
defibrillator capacitor: then the safety relay reopens at slightly below
the new setting, with recharge up to the new energy setting.
2.3.12.5
5.4 V Reference/Low Battery Shutdown (Figure 2-53)
U6 is an adjustable reference, with R132 used to obtain 5.40 +/- 0.20V.
reference is
used for: (1)
comparator UIB, which
switches Q9
This 5.4 V
to turn off U3 if
V-bat (or V-reg) drops to 9.5 V and "restart enable" if it goes back up to about
10V.
(Note: these trip points may vary +/- 0.4 due to normal component
tolerances); (2) similar circuitry to shut down the low voltage power supply board;
(3) pull-up reference on HV Monitor Amplifier U1C (Figure 2-52), and related HV
monitor circuitry on the Defibrillator Control board.
2-44
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-1
6
HV DEFIB
CAP
HV
SNUBBER
f^-^>h
CIOI
R44
JI9
SAFETY
J
RELAY 16 f-1
DRIVE
04
R2I
VW-
x
32/iF
NC
J2I
P2I
i
i
CR7
SAFETY
LOAD
IOK
V
>«>
HV SAFETY
RELAY
!
^3>
rh
Figure 2-52
JI9
i
5.4V REF
MOTHER
<
CRI2I
i
-w—
. J
RI05
BD GND 10 ^-L
CII7
-WW
Low Bottery
Voltage
$
RI3I
RIOI
Vout
TRIM
c
U5
Vin
GND
^\
:CI02
TO PWM
SHUTDOWN
U3 PIN 10
RI03 >RI02>RI04
V
?
Vc (V BAT)
Figure 2-53
40^\
2-45
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-2
2.3.13
/^I|,
LOW VOLTAGE POWER SUPPLY BOARD 78670-60110
(Refer to Figure 6-12 for detailed schematic)
This circuit board furnishes power to all circuits except the defibrillator H.V.
supply. It incorporates a fly-back power supply which is controlled by a pulse
width modulator (PWM). Refer to Figure 2-54.
The fly-back transformer has
multiple secondary windings to meet the various voltage requirements.
Input
voltage is 9.0 V to 13.2 V on battery and 12.8 V from the 78668 power base.
HV
MULTIPLIER
TO +BATTERY
A
+ 5KV
DRIVE
PULSE WIDTH
CIRCUIT
MODULATOR
POWER
SWITCH
03
PIN I
01,02
PIN 4
RECTIFIERS
FLYBACK
a
+ 200
+ 15
+ I2R
TRANS.
FILTERS
+ 12
-15
I LIMIT
-12
RECTIFIER
LOW BATTERY
SHUT DOWN
d
Tl
FILTER
-o + 5V
VOLTAGE FEEDBACK
FEEDBACK
Figure 2-54
2.3.13.1
Pulse Width Modulator (PWM) Internal Circuits
Refer to Figure 2-55.
The pulse width modulator integrated circuit, Ul, is the control element for the
power supply.
It operates at a fixed frequency of approximately 18 kHz. Duty
cycle control is used to regulate the energy supplied to the transformer, by
varying the "on"time of the transformer switching transistor. The PWM incorporates
an internal +5 volt reference supply, an oscillator, error amplifier, comparator,
current limit, and
duty cycle controlled outputs.
The following circuit
description will discuss the PWM operation.
^^
2-46
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-1
•R34
,£OMP
fe1
_
:c6
Vcc
__| ,_ —
O—-
— — — I I— —
—
r5--i
16
osc
12]
TO Vcc
F.F.
r
IV REG
M6
lb
I+5V REF
oooSi
-^COMPARATOR
|gError Amp
I4|
CURRENT
LIMIT
L_
10
>—
—
l("tt
>
SHUTDOWN^
/77
Figure 2-55
+5 Volt Internal Reference (Pin 16)
P
All circuits, within the PWM integrated circuit, operate from this built in 5 volt
regulator. It is used as a reference for the error amplifier. The +5 volts is
brought out at pin 16 for use in external circuits.
Oscillator (Pins 6 and 7)
The PWM contains an R-C oscillator. The frequency is controlled by R34 and C6. The
oscillator supplies two signals. One is a linear sawtooth which goes to the
internal comparator. The other is a narrow clock pulse which switches the internal
flip-flop.
Flip-Flop
The PWM has two outputs. The flip-flop directs the PWM signal to alternate between
these outputs.
The second function of the flip-flop is to ensure that the two
outputs are never on at the same time.
Error Amplifier (Pins 1 and 2)
The error amplifier supplies a variable reference voltage to the internal
comparator. The error amplifier derives its reference voltage from the internal 5v
regulator through the resistive divider R5 and R7.
The error amplifier has a
relatively high output impedance.This output is brought out on pin 9. This makes
external duty cycle control possible, by setting the maximum input reference
voltage to the internal comparator.
^s
Internal Comparator
The comparator changes its output
by sensing voltage differences at the inputs.
The comparator "on time" (duty cycle) decreases whenever the error amplifier output
voltage is less than the sawtooth voltage applied to the other comparator input.
2-47
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
Current limit (Pins 4 and 5)
The current limiter amplifier reduces the duty cycle by pulling the error amplifier
output toward ground. The error amplifier
with linear response above this point.
input threshold is about 200 millivolts
Output stage (Pins 11 and 14)
The output stage consists of a pair of open collector NPN transistors.
The
transistors supply drive signal to switch transistors Q1,Q2. The PWM outputs are
parallel connected for flyback power supply applications.
Shutdown (Pins 10)
A small positive voltage (0.7v) applied to pin 10 will accomplish a complete
shutdown of the PWM.
The shutdown transistor pulls the error amplifier output
toward ground thus preventing any output from the internal comparator.
2.3.13.2
External
PWM Circuits
Soft Start
Refer to Figure 2-56
This function prevents
large primary current surges during power
supply start up.
CR2, C2 and R4 make up the soft start circuit. When power is applied, pin 9 of Ul
is held at ground by C2. As C2 charges through R4, the error amplifier output
voltage increases. This allows the duty cycle to increase from zero to a point
where the feedback loop takes control,all owing the output to ramp up slowly.
Pulse Width Limit
The pulse width limit protects the power
resistive divider
R2 and
R3 form
supply in case of excessive loading.
a +1.9
volt reference.
CR1 clamps
The
the error
amplifier output to this reference which prevents the error amplifier output from
going above 2.5 volts.
This level corresponds to approximately a 60% pulse width
limit.
6.8
SOFT
PULSE WIDTH LIMIT
JT
rR34
6.9IK
START
C_OMP
______&__-- —
Rl _
6 —
SR6
?5IK
Ul
;c3
.01
:lcri
•C2
*R4
R4
vl.0
>IK
.01
Cr
— i , — — o —— —
Vcc_
— 0 —
15
0SC
121
TO Vcc
F.F
1
-THHl-
VREG
m
7F
5.0V
R5
5.1 K
116
I+5VREF
.01
COMPARATOR
CTQR
L_
I4|
CURRENT
->
:R7
5.IK
X
S%
Error Amp
12.5V
^C5
LIMIT
10
! _ — . _ , >—
ft/77
^ — i ,— ^
SHUTDOWN
m
Figure 2-56
2-48
Rl
CI
^bC6
6
::CR2
100
•VAr
TP3
—
5
—
m
J
SECTION II - THEOR Y OF OPERA TION
Models 78670A178671A
78670A-2
fT^ Drive Amplifier (Refer to Figure 2-57)
The output of the PWM is not sufficient to drive the power switching transistor Q3.
As the PWM produces a positive output pulse, Ql conducts applying turn on bias to
Q3. As Q3 conducts, current flows through the primary of the
Tl, causing energy to be stored in the magnetic field.
power transformer,
When the PWM output goes low, Ql turns off and Q2 turns on, rapidly removing base
drive from Q3.
The magnetic field collapses transferring energy to the secondary
windings. Q2 is normally off when the PWM output is high but turns on when the
output goes low. This ensures a rapid turn off of Q3.
VR1, CR14 and the extra primary winding provide transient protection for
preventing inductive kickback spikes that could damage the transistor.
Q3, by
Current Limit Feedback
When Q3 is conducting, a small voltage appears across the emitter resistor, Rll.
This voltage is fed back to the PWM current limit input and limits the average
current to approximately 2.5 amperes.
V BATT
+ BAT 12 V
£Ul
PWM
13
Ql
R9
»*,
•
C9 a CIO
wvw-
VR
—1(—r-*
14
4
R8
VWNA.
*
RIO
Q2
::CRI4
Rll
rn
CURRENT LIMIT FEEDBACK
Figure 2-57
Low Battery Shutdown (Refer to Figure 2-58)
U7 is configured as a comparator. Its reference comes from the 5.4 volt reference
regulator on the defibrillator H.V. power supply board. When the battery output
falls below 9.0 volts, the normally high comparator output goes low and Q4 turns
off.
This causes a high to appear at the PWM pin 10 which results in PWM
shutdown.The shutdown circuit provides about 1.4 volts of hysteresis. If the
battery recovers or another power source is substituted, U7 output goes high and
normal operation resumes.
2-49
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-1
+BATTERY
+ 5.4V REF.
R35
.1
SR36
R38
R37
c
LMZOp2
R43
R39
CRI6
wv-—m
H—
♦ TO PWM PIN 10
SHUTDOWN
€>
Q4
R42
R40
r
LOW BATTERY
DETECTOR
rh
Figure 2-58
2.3.13.3
5V. Supply Voltage Regulation (Refer to Figure 2-59 and 2-54)
The +5 volt supply is directly regulated by controlling the duty cycle of the pulse
width modulator. R14 and R16 form a voltage divider. 2.5 volts is fed back to the
negative error amplifier input (Ul pin 1). Since all transformer windings are
tightly coupled reasonably good regulation is accomplished on all other supplies.
2-50
s*%
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-2
+ I5V
CR5
-®
e
irCRil
U6
LM3I7T
+I2VREG
IN
+I2V
OUT
©
;ci2
R44
215
R28:
CI8
©12V ADJUST
R45
GND
<S-r
<S)
:C20
:ci5
2 COM
IN
RI4
c
U4
7812
+ I2VREG
+ I2R
OUT
-I5V
CR7
-H—
O
or
IN
U5
7912
-12 V
OUT
<S>
-I2VREG
I COM
7kci7
+5V
L4
CR6
-H
^crio
/YYY\.
r
;ci3
o
RI6
3 LI
C24
m
TO PWM PIN I
R32
-Vw\—
VOLTAGE FEEDBACK
RI4S*—|
5V ADJUST
Figure 2-59
2-51
SECTION II - THEOR Y OF OPERA TION
Models 78670A/78671A
78670A-1
2.3.13.4
<^^^
CRT Supplies (+5000 and +200 volts)
The CRT grids require approximately +200 volts, while +5000 volts is needed for the
anode. The source for both supplies is a single 975 volt secondary.
Voltage regulation of the CRT Supplies
Figure 2-60
shows the output
waveform of the
high voltage secondary winding and
where the clipping action of the Zeners occurs. The ringing of the waveform is
always present but the degree will vary depending on the load presented to the
power supply.
600V
CLIPPING
.00
1111
11 it
i ill ij 11 /1 ill
i fliiAT 'mi Mill
1 I l i t II1 1 r iu m . n i l
ill • hit • I1
fill!
I Vi
f""\W
uv
1
i__
-350V
CLIPPING
Figure 2-60
C25
220 pF
HV
-^•-i-5KV
MULTIPLIER
VR2
VR5
(200V)
(200V)
VR6
VR4
(200V)
(150V)
XR8
CRI5jfc
ft?
$
|VR3
^L_CII
.01
(200V)
CR4
Figure 2-61
2-52
+ 200V
rh
/e^%
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-2
Theory of Operation-CRT Supply
1. During positive peaks VR2, VR6, VR3 and CR4 conduct when the voltage exceeds
+600 volts. The zeners form a voltage divider with VR3 providing +200 volts
reference to ground.
2.
Refer to paragraph 2.4.9.19 and 2.4.9.20 for details
on the energy discharge
function.
3.
The high
voltage multiplier receives a waveform which is clipped
at +600 and
-350 volts = 950V P-P.
4.
The negative
peak varies with battery
voltage while the positive
peak varies
with battery voltage, loading and duty cycle.
5.
The series capacitor, C25, limits current, and to a degree, controls the clipping
action of the zener diodes.
2.3.13.5
+ and -15 Volt Supplies (Refer to Figure 2-59)
The + and -15 volt supplies are used for the CRT deflection amplifier and print
head dots. These supplies incorporate only the moderate regulation afforded by the
close magnetic coupling to the 5V. winding.
2.3.13.6
+ and -12 Volt Supplies
Two +12 volt and one minus 12 volt supplies are required by the instrument. U4 and
U5 are linear, fixed voltage 3 terminal regulators. U6 is a 3 terminal adjustable
regulator, which provides power to reference circuits that require a more accurate
voltage than the tolerance of the fixed voltage regulator allows.
2.3.13.7
Noise Filtering
By its very nature, a switching type power supply is a noisy device. The + and -15
volt and the +5 volt power supplies incorporate series inductors, L2, L3 and L4 in
their outputs, to reduce noise on the supply lines. LI and C14 filter the 5 volt
supply feedback to the PWM.
2.3.14
Service Switch
The service switch, located on the QRS beeper volume control, is used to place the
unit in various self test modes and when setting the real
time clock.
The beeper
volume control is pulled to place the unit in the service mode.
Refer to paragraph
iS^A
2.4.9.19 and 2.4.9.20 for details
on the energy discharge
function.
Paragraph 3.4.2.3 describes
pattern is also
the service mode for checking the
displayed on the monitor
recorder.
The test
CRT which provides a method of checking
the response of the ECG section.
2-53
SECTION II - THEOR Y OF OPERA TION
Models 78670AJ78671A
78670A-l
2.3.12
Annotation Printout
Dip switch assembly A7-S1 selects printout by the annotating recorder,
printout information and switch positions are shown in Figure below.
The
Full documentation prints delivered energy, current and patient impedance. Partial
documentation omits delivered energy and current and prints only patient impedance.
U
A7
CLOCK/HEART RATE BD
RELATIVE
TIME
FULL
DOCUMENTATION ENGLISH
_^__
r
\
4
3
2
I
V
REAL
TIME
i^^Slv
J
^—
A7SI
t
I
000
*
PARTIAL
FRENCH
DOCUMENTATION
"^k
2-54
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
f^
SECTION III - CHECKS AND ADJUSTMENTS
Models 786 70A/786 71A
786 70A-1
DEFIB CONTROL
A10
FLEX CIRCUIT A16
Figure 3-0. Circuit Board Locator.
3-0
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A /786 71'A
786 70A-1
SECTION III
CHECKS AND ADJUSTMENTS
3.1
INTRODUCTION
This section contains three major parts as follows:
A.
Level II Performance, Safety and Maintenance Checks
These checks
include a battery
capacity test
procedure, and should
normally be
performed every six months.
B.
Internal Adjustment Procedures
Internal adjustments are made at the factory and normally do not require attention.
If assemblies are repaired or replaced, however, check and adjust as necessary.
Adjustment location and purpose of adjustments are listed in Table 3-3.
C.
Specification Checks
This part
consists of
test procedures to
ensure the
instrument is
operating to
specification.
3.2
LEVEL II PERFORMANCE, SAFETY AND MAINTENANCE CHECKS
Perform
these checks
recommended.
every
Record the
six
months.
For
best
results,
use the
defibrillator serial number and the date
equipment
the checks were
performed.
3.2.1
Test
Test Equipment
equipment
required for
performing the
level
II performance,
safety
and
maintenance checks is listed in Table 3-1. Table 3-2 lists the equipment necessary
if the Dempsey model 431F safety analyzer is not used.
Test equipment characteristics and a recommended commercial model are included. If
the recommended model is not available, select another with similar characteristics
and capablities.
WARNING
LETHAL VOLTAGES ARE PRESENT INSIDE THE DEFIBRILLATOR AND ARE
EXPOSED WHEN THE DEFIBRILLATOR COVERS ARE REMOVED. DO NOT WORK
INSIDE THE INSTRUMENT WHEN POWER IS APPLIED OR IF DEFIBRILLATOR
IS CHARGED.
3-1
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
/*%
Table 3-1
REQUIRED TEST EQUIPMENT FOR LEVEL II PERFORMANCE, SAFETY, and MAINTENANCE TESTS
DIGITAL VOLTMETER
Recommend:
HP 3466A
Capable of 5 to 15 V DC +/- 1%
OHMMETER
HP 3466A
Capable of 0.1 to 10 ohm +/- 2%
ENERGY METER
Capable of 5 to 400 Joule, critically
damped sinusoidal waveform measurements
with +/- 2% of full scale accuracy.
measurements
measurements
Recommend:
Dempsey Model 429
STOPWATCH OR TIMER
Load resistance 50 ohm +/- 0.5%.
Capable of measuring 2 to 12
second events with hand start/
stop actuation to 1/4 sec.
accuracy
Output Level: 1 mV
Range: 60 and 120 BPM calibrated
ECG SIMULATOR
Recommend:
Parke-Davis
3175
TEST LOAD
HP 78620-60860
Paddle Contact Indicator
Test Resistors
outputs
2fl, 200 WATT 5%
61.1 ohms, 64.9 ohms, 250.0 ohms, all 1%
TEST CABLES AND COMPONENTS
(1)
(1)
HP 14489A
HP 14151A
1
HP 14445A
Patient Cable
Electrode Lead Set
ECG Electrodes
HP 78660-67800
Test Load Adapter
(1)
SAFETY ANALYZER
See Table 3-2 for substitute
Recommend:
equipment
Dempsey Model 431F
3-2
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-1
f^
Table 3-2
EQUIPMENT NECESSARY IF THE DEMPSEY MODEL 431F SAFETY ANALYZER IS NOT USED
REQUIREMENT
NECESSARY QUALIFICATIONS
DIGITAL VOLTMETER
Capable of 10 mV DC +/- 0.5%
Recommend:
HP 3466A
measurements
2 TO 3 WIRE AC
Must have ground wire pig-tail
PLUG ADAPTOR
HP 1251-1852
TEST PLUG FOR 120 VAC SOURCE
HP 04655-60100
CURRENT METERING NETWORK
1 Mfi resistor in hot lead
HP 1251-1284
HP 0757-0159
HP 0757-0984
Dual Banana Plug
HP 0160-3238
0.15 uF Capacitor
1 Kfi 1% Resistor
lOKfi 1% Resistor
CONNECTED AS FOLLOWS:
IKfl
i\
O—<>
O
u-AAAr
no O.I5/xF
^
10"
15/xF
Ground Test Cable
NEMA Male Plug
HP 1251-3133
HP 8120-0022
(2) H. H. Smith,
331
Cable, 6 feet required
Alligator Clip,
1 green, 1 black
CONNECTED AS FOLLOWS
CONNECTED TO
GROUND
(GREEN COVER)
CONNECTED TO
COMMON
(BLACK COVER)
3-3
SECTION 111 - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
7867(1.1-/
1.2.7.
1
Functional Performance Testing
These tests are performed to assure that the Defibrillator is functioning reliably.
3.2.2.1
Energy Accuracy.
Connect the equipment as shown in Figure 3-1.
DEFIBRILLATOR
MODEL 429
DEMPSEY METER
Figure 3-1. Energy Accuracy Test Setup.
Set the
ENERGY SELECT
control to
each of
the positions
indicated in
the table
below; press the CHARGE button and allow the unit to charge. The CHARGE DONE lamp
will light at the end of each charge cycle. Firmly press the paddles to the energy
meter and press both DISCHARGE buttons simultaneously. Record the energy levels
measured. If the unit is equipped with an annotatinq recorder (78670A), refer to
the
printed
information
for
confirmation
of
the
delivered
information.
THE OUTPUT SHOULD CONFORM TO THE FOLLOWING:
Energy Select
Setting
5
10
20
30
5
+/-
4
200
10 +/- 4
20 +/4
30 +/- 4.5
50 +/7.5
70 +/- 10.5
100 +/- 15
150 +/- 22.5
200 +/- 30
300
360
300
360
50
70
100
150
3-4
Energy
(Joules)
Delive ^ed
+/- 45
+/- 54
energy
waveform
^
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
^s
3.2.2.2
Self Testing Accuracy
1. Make sure the paddles and the paddle contacts in the storage pockets are clean
and free of contaminants. This is to assure good electrical contact to prevent
paddle surface damage during discharge.
2.
Place the paddles firmly in their storage positions.
3.
Put the unit in the service mode.
To enter the service mode, proceed as follows:
a.
Turn the unit off.
b.
Pull up on the BEEPER VOLUME knob.
c. Turn the unit on and immediately push down on the BEEPER VOLUME knob. At
this point you should see the test waveform displayed on the CRT. If this display
does not appear, repeat the procedure.
4.
Put the ENERGY
SELECT switch in the 100 Joule
position.
Charge and discharge
the unit.
5.
^
The LCD display should flash the test
discharge energy of 90-110 Joules and if
the unit is equipped with an annotating recorder (78670A) it
should print out the
test energy.
6. Place the ENERGY SELECT switch in the 360 Joule energy
discharge the unit. The LCD should display 324-396 Joules.
7.
Charge and
Turn the unit off to get out of the service mode.
3.2.2.3
1.
position.
Defibrillator Capacitor Charge Time
Install a fully
charged
battery of known' good
defibrillator to a Model 78668A Power Base.
condition or connect the
The A-C line voltage to the Power Base
must be 110 to 120 VAC.
2. Use a stop watch or similar device to measure the time from pressing the CHARGE
button until the unit's CHARGE DONE light comes on.
3.
The following indicates the allowable charging times:
Charge Time (Seconds)
Energy
f*
3.2.2.4
1.
Setting
Battery
Power Base
360
8-10
6-8
Synchronizer
Put the ECG SOURCE SELECT switch in the LEADS I position.
3-5
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
/lS%\
2. Adjust the ECG SIZE control for 1.0 cm deflection on the CRT display when the
CAL button is pressed.
3.
Press the SYNC/DEFIB switch to the SYNC position and release.
A negative going
sync pulse should appear at the leading edge of every CAL pulse each time the CAL
switch is pressed.
4.
Place the paddles in their storage pockets.
5.
Set the ENERGY SELECT CONTROL to 20 Joules and press CHARGE.
6.
After the CHARGE
DONE indicator lights, press and hold
the DISCHARGE buttons.
The defibrillator should not fire until the CAL button is pressed generating a sync
signal.
7. Place the ECG SOURCE SELECT switch in the paddles position and repeat step 3.
No sync pulses should appear since the sync feature is locked out in the paddles
position.
3.2.2.5
ECG Amplifier Noise
Turn the ECG SOURCE switch to the LEADS II position. Turn the ECG SIZE control
clockwise (but not past the detent into AUTO) to full gain. Observe the trace for
excessive line width.
Compare the line width with that at minimum gain. Repeat
tests with the paddles in their storage pockets and the ECG SOURCE switch in the
PADDLES position.
3.2.2.6
1.
ECG Amplifier Gain
Turn ENERGY SELECT control to MONITOR ON.
2. Turn the ECG SIZE control fully counter-clockwise. Press the CAL button and
observe the CRT trace. The deflection should be equal to, or less than 0.250 cm.
3.
Turn the ECG SIZE control fully clockwise to maximum gain, but not past detent
into AUTO. Again press the CAL button.
The trace should deflect upwards to the
top of the screen. Rapidly press and release the CAL button repeatedly. The trace
baseline should gradually move downward until the full deflection of the CAL signal
is viewable.
The deflection should be at least 2.0 cm.
4. Place the instrument in the service mode (turn the instrument OFF, pull the
BEEPER VOLUME knob UP.
Turn the instrument ON and quickly push the BEEPER VOLUME
knob DOWN). Turn the ECG SIZE control clockwise past detent to AUTO. Observe the
ramp/step waveform.
Immediately following the largest
step, there is a two second
period of flat baseline preceding the triangular ramp.
During this baseline
period, quickly press the CAL button five times and observe five steps of
increasing amplitude on the CRT screen.
(Refer to Figure 3-2).
This represents
the five gain stages of AUTO and can also be observed
equipped. Turn unit off to get out of the service mode.
3-6
on the
Recorder if
so
SECTION III - CHECKSAND ADJUSTMENTS
Models 78670A /786 71A
78670A-1
'
,-
FIVE GAIN STAGES
00
llii
:".: :
h'R
i Tl
j
!
'•'•.':':
. .
f~
;::
ii1
;
I
:.
:
v
::
\
::;:
:
1|
\
,—
/
:
•:
HI
J
K
::::
m
!
II III;
.
: :::!
\
llii
Figure 3-2. Five Gain Stages of AUTO.
WARNING
BEFORE PERFORMING STEP 5, VERIFY THAT UNIT IS ON MONITOR AS
STEP 1.
INSTRUCTED IN
5. Switch the ECG SOURCE to PADDLES with the ECG SIZE to AUTO. Turn the paddles
over in their holders to expose the contact electrodes. Rest the heel of your
hands on the electrodes and relax.
Watch for the ECG waveform indicating the
paddle ECG is functional.
3.2.2.7
Heart Rate Accuracy and Alarm
1.
Connect the test equipment as shown in Figure 3-3.
2.
Turn the defibrillator ON; turn ECG SOURCE to LEADS I position.
3.
Turn the ECG Simulator ON and adjust the defibrillator ECG SIZE control display
for 1 cm R-wave deflection on the monitor.
4.
Check
the heart
switch positions
rate digital
display in the
of the ECG Simulator.
calibrated 60 BPM and
The heart rate accuracy
120 BPM
specification is
+/- 5% or 2 BPM (whichever is greater).
5.
Place the
ALARM switch in the ON
position with the ECG Simulator
at 120 BPM.
The alarm should not sound.
14489A
ECG
IN
(
TL
ECG GENERATOR/
CALIBRATOR
r
Figure 3-3. Heart Rate Accuracy and Alarm (78670A &78671A-deleted on 78671A with Option A02).
3-7
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-l
6. Press the CAL button rapidly enough to raise the heart rate to over 150 BPM. ^
Maintain the higher rate until, after about 4 seconds, the alarm sounds. The
recorder will run for 16 seconds; time and heart rate are annotated (78670A only).
7.
Turn the
ALARM OFF and set the ECG
Simulator to 60 BPM.
After the count has
stabilized, turn the alarm back on.
8.
Turn
the ECG Simulator OFF, and again the ALARM
should sound in
about four
seconds.
3.2.2.8
1.
Paddle Contact Indicator (PCI) Test
Turn
the instrument
pockets.
The first
ON to MONITOR and
remove the
paddles from
light bar (closest to the handle)
the storage
on the PADDLE CONTACT
indicator should light and blink on and off.
2.
Connect a61.1ohm resistor between paddle electrodes. All the light
bars should
light.
3.
Connect a 250.0 ohm resistor between paddle electrodes. Only twolight bars should
light.
3.2.3
Safety and Maintenance Checks
3.2.3.1
Preliminary Safety Checks
Make these initial checks before performing the safety tests.
1. Check that paddle electrodes are in good condition, clean and not pitted.
Check paddles for obvious cracks (small chips, gouges and scratches are acceptable
and will not affect instrument performance). Check cable strain reliefs for cracks
or other signs of deterioration at the paddles.
2. Check resistance of paddle cables (from paddle to paddle), WITH CABLE STRESSED
by stretching the cables out to their entire length while 'resistance is being
measured.
Resistance should be approximately 303 Ka, paddle to paddle,
includes a high voltage suppressor network in the paddle ECG input.
defibrillator case is
open, a direct resistance
measurement of each cable
which
If the
can be
made from the paddle electrode face to the H.V. connector which mates the paddle
cable to the unit.
This reading should be less than 1.0 ohm.
3.
CHARGE button will initiate charge when
Check that the
the cable is stretched
to its full length.
4.
Check that
both DISCHARGE buttons must be pressed to discharge the
defibrillator. This is done by attempting to discharge the defibrillator by only
pressing ONE
of the buttons
then the other, after
test with the cables stretched to their full length.
3-8
releasing the first.
Do this
SECTION III- CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.2.3.2
Power Cord to Chassis Ground Resistance Check.
This applies when the Defibrillator is used with a 78668A Power Base.
DEFIBRILLATOR
DEMPSEY 431F TESTER
POWER BASE
(REAR VIEW)
Figure 3-4. Power Cord to Chassis Ground Resistance Check.
1. Set the instrument up for the test as shown in Figure 3-4. Connect a short
heavy wire to the external ground jack on the rear panel of the defibrillator to
allow access of this point during the test.
If the Dempsey 431F is not available,
use a conventional ohmmeter capable of accuracy at 0.2 ohms.
2. Connect the dual banana plug of a Kelvin Kable between the LO meter terminal of
the Dempsey and the - (negative) terminal of the 1/2-AMP source on the Dempsey.
3.
Connect the
clip on the other end of
the Kable to the ground pin
of the male
power connector.
4.
Connect the dual banana plug of the second Kelvin Kable between the HI terminal
of the meter section and the + terminal of the 1/2-AMP source.
5.
Connect the clip on the other end to a banana/banana cable inserted
in the
external ground jack on the rear panel of the Power Base.
6. Press MILLIOHMS and read the resistance
is less-than-or-equal-to 0.20 ohms.
on the current ranges.
The test limit
7. Reconnect the clip on the Power Base external ground to the short wire attached
to the defibrillator external ground jack.
Take a resistance reading.
The test
limit maximum is 0.20 ohms. If the limit is slightly exceeded, make a resistance
measurement
of the
short access
wire and
subtract
the reading
from the
total
resistance to obtain actual ohmic resistance of the units.
3-9
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
PADDLES
(BOTTOM VIEW)
14445A ELECTRODES
APPLIED TO PADDLES
WITH ADDITIONAL
REDUX PASTE
ALLIGATOR-ALLIGATOR CLIP LEADS, LENGTH LESS THAN
6 INCHES, SHOULD BE USED TO CONNECT ELECTRODESTO
TEST EQUIPMENT AS SHOWN IN THE STEP DIAGRAMS.
Figure 3-5. Test Connections to Paddles.
ISOLATED
INSTRUMENT
UNDER TEST
TEST RECEPTACLE
FUNCTION
CURRENT
SELECTOR
TEST III
TEST V
USING THE DEMPSEY
REVERSE POLARITY
MODEL 431F
LIFT GROUND
NOTE: WHEN USING AN HP MULTIMETER, PERFORM BOTH AN AC AND A DC MEASUREMENT. THE DEMPSEY 431F
RESPONDS TO BOTH AC AND DC SIMULTANEOUSLY.
B
ISOLATED
CURRENT METERING
INSTRUMENT
NETWORK
UNDER TEST
1' I '
i
INSULATING PAD
USE TWO WIRE ADAPTER
WITH GROUND WIRE TO
ALLOW REVERSAL AND
UNGROUNDING
TEST MEASURES PADDLE
LEAKAGE TO GROUND
CONNECT TO GROUND
FOR GROUNDED TEST
CONDITION. LEAVE
DISCONNECTED FOR
UNGROUNDED TEST
BLACK (COMMON)
CONDITION.
USING RECOMMENDED
HP EQUIPMENT
GROUNDING TEST CABLE
(PLUG IN DURING TEST. CAUTION-DO NOT TOUCH
EXPOSED CONDUCTORS WHEN PLUG IS INSERTED)
Figure 3-6. Paddle Leakage Current to Ground.
3-10
**\
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
^
3.2.3.3 Paddle Leakage Current (Source Leakage) to Ground.
Perform the check as follows:
1. Connect the test equipment as shown in Figure 3-6.
If the Dempsey 431F is
used, follow instructions included in the figure. Use clip leads (see Figure 3-5)
to connect the Apex paddle to the RA output of the Dempsey and the Sternum paddle
to the LA output.
2. Set Dempsey FUNCTION switch to CURRENT.
(Set the SELECTOR switch to either RA
or LA to test either paddle. For paddle-to-paddle checks, ground either paddle and
test the other.)
3. Using the SELECTOR switch to connect the appropriate paddle,
source leakage to ground for each paddle individually.
than 20 uA paddle-to-ground.
4.
measure paddle
Current should
be no more
Perform the same test under each of the following conditions with the power ON
and with the power OFF.
WARNING
MAKE ALL PADDLE TEST CONNECTIONS BEFORE PERFORMING CHECK NUMBER
FIVE.
KEEP PADDLES SEPARATED AND ON INSULATED PAD DURING TEST.
(a) Chassis grounded, standard power polarity.
(b) Chassis grounded, reverse power polarity.
(c) Chassis ungrounded, standard power polarity.
(d) Chassis ungrounded, reverse power polarity.
(e) Defibrillator charged to highest energy setting.
(f) Defibrillator discharged (discharged by turning
control.
A
power OFF with
energy select
DO NOT PRESS DISCHARGE BUTTONS).
ISOLATED
INSTRUMENT
UNDER TEST
TEST RECEPTACLE
FUNCTION
CURRENT
SELECTOR
TEST III
TEST V
USING THE DEMPSEY
REVERSE POLARITY
MODEL 431F
LIFT GROUND
Figure 3-7A. Paddle Leakage Test with 115V Applied.
3-11
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-l
NOTE:
WHEN USING AN HP MULTIMETER, PERFORM
BOTH
AN
DEMPSEY
AC
431F
AND
A
DC
RESPONDS
MEASUREMENT.
TO
BOTH
AC
AND
THE
DC
SIMULTANEOUSLY.
I(/«A) =
METER READING IN mV
1000
ISOLATED
CURRENT METERING
INSTRUMENT
NETWORK
UNDER TEST
PLUG IN DURING TEST.
CAUTION-DO NOT TOUCH
EXPOSED CONDUCTORS
WHEN PLUGGED IN
GROUND
USING RECOMMENDED HP EQUIPMENT
READINGS OVER 80 MICROAMPERES
ARE NOT VALID SINCE ISOLATION
TEST PLUG LIMITS CURRENT
Figure 3-7B. Paddle Leakage Test with 115V Applied.
3.2.3.4
Paddle Leakage Current (Sink Current) with 115 Volts Applied.
Perform the check as follows:
1. Connect the test equipment as shown in Figure 3-7.
If the Dempsey 431F is
used, also follow the instructions included in the figure. Use clip leads as in
Figure 3-5, to connect the Apext paddle to the RA output of the Dempsey and the
Sternum paddle to the LA output.
2.
Set Dempsey FUNCTION switch to CURRENT.
3.
Turn the SELECTOR to Test V.
4.
Press
red 115V test button under each of the following conditions
power ON and the power OFF.
Current should be no more than 100 uA.
CONDITIONS:
(a) Chassis grounded, standard power polarity.
(b) Chassis grounded, reverse power supply.
3-12
with the
SECTION III - CHECKS AND ADJUSTMENTS
Models 78660A/78661A
78660-1
i^N
14489A
PATIENT CABLE
ISOLATED
INSTRUMENT
UNDER TEST
PLUG
THE
THE
INSTRUMENT
TEST
LOCATED
ON
SAFETY
TOP
OF
ANALYZER.
CONNECT
MENT'S
THE
ECG
(LA,
RL,
SET
FUNCTION
RA)
CURRENT.
THE
DUCTED
THE
OF
CONNECTORS.
SWITCH
THE
TEST
SWITCH.
GROUND
IS
ADVANCING
SWITCH
POLARITY
BEEN
CON
THE
THROUGH
POSITIONS
III PORTION OF
PRESS THE
AND/OR
LIFT
REVERSE
BUTTONS
OBTAIN
TO
THESE
HAVE
APPLICABLE
THE
THE
LABELED
TEST
BY
SELECTOR
TO
AFTER
CONNECTIONS
THE
THEN
INSTRU
LEADS
APPROPRIATELY
MADE,
INTO
RECEPTACLE
DESIRED
TO
TEST
CONDITIONS.
USING THE DEMPSEY MODEL 431F
Figure 3-8A. Patient Lead Leakage Current to Ground Test.
^\
NOTE: WHEN USING AN HP MULTIMETER, PERFORM
B
BOTH
AN
DEMPSEY
14489A
PATIENT CABLE
AC
431F
AND
A
DC
RESPONDS
MEASUREMENT.
TO
BOTH
AC
AND
THE
DC
SIMULTANEOUSLY.
USE TWO WIRE ADAPTER
WITH GROUND WIRE TO
ALLOW POLARITY REVERSAL
AND UNGROUNDING
TEST MEASURES PATIENT
CONNECT TO GROUND
LEAD LEAKAGE TO GROUND
FOR GROUNDED TEST
CONDITION. LEAVE
DISCONNECTED FOR
UNGROUNDED TEST
BLACK (COMMON)
CONDITION.
GROUNDING TEST CABLE
(PLUG IN DURING TEST. CAUTION-DO NOT TOUCH
EXPOSED CONDUCTORS WHILE PLUGGED IN)
USING RECOMMENDED HP EQUIPMENT
Figure 3-8B. Patient Lead Leakage current to Ground Test.
3-13
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-l
3.2.3.5
^\
Patient Lead Leakage Current (Source Leakage) to Ground.
Perform the check as follows:
1.
Connect the test equipment as shown in Figure 3-8.
If the Dempsey 431F is
used, follow instructions included in the figure.
2. Perform the tests of Step 3 under each of the following power polarity and
grounding conditions with the power ON and with the power OFF.
(a) Chassis grounded, standard power polarity.
(b) Chassis grounded, reverse power polarity.
(c) Chassis ungrounded, standard power polarity.
(d) Chassis ungrounded, reverse power polarity.
3. Using the patient cable in the test setup, measure each patient lead leakage
current to ground. When a voltmeter is used to derive leakage current, divide the
meter reading in millivolts by 1000.
Result is current in microamperes.
TEST LIMIT: NOT TO EXCEED 10 MICROAMPERES.
14489A
PATIENT CABLE
ISOLATED
INSTRUMENT
UNDER TEST
PLUG THE
THE
LOCATED
TOP
OF
ANALYZER.
CONNECT
MENT'S
INSTRU
LEADS
(LA,
RL,
SET
FUNCTION
RA)
CURRENT.
THE
DUCTED
SWITCH
HAVE
SWITCH
TEST
GROUND
Figure 3-9A. Leakage Current Between Patient Leads Test.
BEEN
CON
THROUGH
POSITIONS
IV PORTION OF
PRESS THE
LIFT
REVERSE
BUTTONS
DESIRED
CONDITIONS.
USING THE DEMPSEY MODEL 431F
IS
AND/OR
POLARITY
OBTAIN
TO
THESE
ADVANCING THE
THE SWITCH.
3-14
CONNECTORS.
APPLICABLE
•OF THE
THE
LABELED
TEST
BY
SELECTOR
THE
TO
AFTER
CONNECTIONS
THE
THEN
THE
ECG
APPROPRIATELY
MADE,
INTO
RECEPTACLE
ON
SAFETY
NSULATING PAD
INSTRUMENT
TEST
TO
TEST
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-1
NOTE: WHEN USING AN HP MULTIMETER, PERFORM
B
BOTH
AN
DEMPSEY
AC
AND
431F
A
DC
RESPONDS
MEASUREMENT.
TO
BOTH
AC
AND
THE
DC
SIMULTANEOUSLY .
14489A
PATIENT CABLE
CURRENT METERING
ISOLATED
INSTRUMENT
UNDER TEST
\U
V!IIII I 1 I I I 11 I I
INSULATING PAD
NETWORK
ECG OR PACEMAKER
CONNECTIONS
GREEN
USE TWO WIRE ADAPTER
WITH GROUND WIRE TO
ALLOW POLARITY REVERSAL
AND UNGROUNDING
TEST MEASURES LEAKAGE
CURRENT BETWEEN LEADS
CONNECT TO GROUND
FOR GROUNDED TEST
CONDITION. LEAVE
DISCONNECTED FOR
UNGROUNDED TEST
CONDITION.
USING RECOMMENDED
GROUNDING TEST CABLE
(PLUG IN DURING TEST. CAUTION-DO NOT TOUCH
HP EQUIPMENT
EXPOSED CONDUCTORS WHILE PLUGGED IN)
Figure 3-9B. Leakage Current Between Patient Leads Test.
3.2.3.6
Leakage Current Between Patient Leads Check
Perform the check as follows:
1.
Connect
the test equipment
as shown in
Figure 3-9.
If the Dempsey
431F is
used, also follow the instructions included in the figure.
2. Perform the tests of Step 3 under each of the following power polarity and
grounding conditions with the power ON and with the power OFF.
(a) Chassis grounded, standard power polarity.
(b) Chassis grounded, reverse power polarity.
(c) Chassis ungrounded, standard power polarity.
(d) Chassis ungrounded, reverse power polarity.
r
3. Using a patient cable, measure the leakage current between individual patient
input leads. When a voltmeter is used to derive leakage current, divide the meter
Result is current in microamperes.
Test limit:
reading in millivolts by 1000.
less than or equal to 10 microamperes.
3-15
SECTION HI - CHECKS AND ADJUSTMENTS
Models 78660A/78661A
78660-1
14489A
PATIENT CABLE
PLUG
THE
THE
ISOLATED
INSTRUMENT
TEST
INSTRUMENT
LOCATED
UNDER TEST
SAFETY
INTO
RECEPTACLE
ON
TOP
OF
ANALYZER.
CONNECT THE
APPLICABLE
THE
THEN
INPUTS OF THE
TEST
ADAPTER
TO THE LL, LA, RA. R L. AND C
INSULATING PAD
CONNECTORS ON
THE
SAFETY
ANY
ORDER.
SWITCH
THE
TO
V
LEADS
TEST
TO
115V
BY
TO
THE
COMBINED
115V
APPLIED,
CURRENT
MICROAMPERES.
PRESS
REVERSE POLARITY TO
DESIRED
TEST
USING THE DEMPSEY MODEL 431F
Patient Lead Leakage Current Test with 115V Applied.
NOTE: WHEN USING AN HP MULTIMETER, PERFORM
BOTH
AN
DEMPSEY
AC
431F
AND
A
DC
RESPONDS
MEASUREMENT.
TO
BOTH
AC
THE
AND
DC
SIMULTANEOUSLY.
I luA) =
14489A
METER READING IN mV
PATIENT CABLE
ISOLATED
INSTRUMENT
UNDER TEST
/
/
/
1000
H4^
CURRENT METERING
NETWORK
//r7<\
INSULATING PAD
PLUG IN DURING TEST.
CAUTION-DO NOT TOUCH
EXPOSED CONDUCTORS
WHEN PLUGGED IN.
READINGS OVER 80 MICROAMPERES
ARE NOT VALID SINCE ISOLATION
TEST PLUG LIMITS CURRENT
USING RECOMMEMDED HP EQUIPMENT
Figure 3-10B. Patient Lead Leakage Current Test with 115VApplied.
3-16
TEST
IS 9.58
CONDITION.
B
THE
APPLY
LIMIT
OBTAIN
Figure 3-1 OA.
TO
THE
PRESS
THE
FOR
LEAKAGE
THIS TEST
COMBINE
BUTTON
TO
LEADS.
TURN
SWITCH
PROVIDED
RED
IN
FUNCTION
CURRENT.
ADAPTER.
115V
GROUND DURING
SET
SELECTOR
TEST
DO NOT LIFT
THE TOP OF
ANALYZER
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
{*
3.2.3.7
Patient Lead Leakage Current (Sink Current) with 115 Volts Applied.
Perform the check as follows:
1. Connect the test equipment as shown in Figure 3-10. If the Dempsey 431F is
used, also follow the instructions included in the figure.
2.
Perform the tests of Step 3 under each of the following power polarity
conditions with the chassis GROUNDED and with the power ON and with the power OFF.
(a) Chassis grounded, standard polarity.
(b) Chassis grounded, reverse power polarity.
Using the exact test setup shown, measure the patient lead leakage current for
3.
all
leads tied together while driving the leads with
line voltage.
When a
voltmeter is used to derive the leakage current, divide the meter reading in
millivolts by 1000. Result is current in microamperes. Test limit: < 10
microamperes. In addition, perform both an AC and a DC measurement when using a
voltmeter for the measurements.
The Dempsey 431F
responds
to both AC and DC
simultaneously.
3.2.3.8
Battery Capacity Check.
This check tests the capacity of the defibrillator battery.
To
perform the test,
use an HP 78620-60860 Battery Test Load, and 78660-67800 Cable Adaptor.
TEST CABLE
In 1
/
CABLE
ADAPTER
78660-67800
BATTERY
+
/
HP 78620-60860
TEST LOAD
_/"\
VOLTMETER
Figure 3-11. Test Setup for Battery Capacity Check.
1. The battery should be fully charged at the start of this
least 16 hours if the battery has been discharged.
2.
Connect the DVM to the test load voltmeter terminals.
test.
Charge for at
Use the adapter cable to
connect the battery to test load.
3.
Connect
the battery
to the
test load
and time
the discharge.
The voltage
should not fall below 10 volts in 15 minutes.
4.
If the battery fails the test, recharge for 16 hours and repeat the test.
5.
6.
If the battery fails the second time, recharge and repeat.
If it fails the third time, replace the battery (P/N 78660-60401).
NOTE: Do not allow the battery voltage to fall below 9 volts.
cell reversal which will damage the battery.
Doing so can cause
WARNING
THE BATTERY TEST LOAD BECOMES HOT WHEN USED TO TEST BATTERY CAPACITY. DO NOT
TOUCH OR PLACE NEAR ANY PLASTIC OR COMBUSTIBLE MATERIALS.
SURFACE TEMPERATURES
OF THE TEST
LOAD ENCLOSURE WILL APPROACH
75 DEGREES C (167
DEGREES F) DURING
TESTING.
3-17
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-l
3.3
ADJUSTMENTS
3.3.1
Equipment Required
All test equipment necessary to make the adjustments is listed in each Adjustment
Procedure.
In addition to the test instruments, an
78304-60260) will be needed to make adjustments to the Real
Extender board (H-P
Time Clock/Heart Rate
Board (78660-60260).
Adjustments for both Models 78670A and 78671A are listed in Table 3-3.
3.3.2
Related Adjustments
Although most internal adjustments can be made individually, some controls interact
and some adjustments affect parameters on other circuit boards. Interactions will
be noted in the procedures.
3.3.3
Adjustment Location
To gain access to the adjustment controls, the instrument case must be opened and,
for certain adjustments, the metal circuit board shield removed. See Section IV of
this Service Manual for instructions. The individual adjustment location is shown
in the Adjustment Procedures.
TABLE 3-3
Adjustment
Paddle Contact
Procedure
Number
3.3.4
Reference
Designator
A3-R91
Indicator Adj.
+5 V Adj.
Location
ECG Analog Board
(78670-60155)
3.3.5
A12-R14
Low Voltage Power
Supply (78660-60110)
+12 V Adj.
3.3.5
A12-R28
Low Voltage Power
Supply (78660-60110)
ECG Cal Adj.
3.3.6
A3-R72
ECG Analog Board
(78670-60155)
ECG Baseline Offset
3.3.7
A3-R73
Adj.
Minimum Brightness
Adj.
3-18
ECG Analog Board
(78670-60155)
3.3.8
A6-R26
Deflection Board
(78660-60180)
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
Maximum Brightness
3.3.8
A6-R25
Adj.
Vertical Gain
(78660-60180)
3.3.8
A6-R1
(Y-Axis) Adj.
Horizontal Gain
Deflection Board
(78660-60180)
3.3.8
A6-R2
(X-Axis) Adj.
Beam Centering
Deflection Board
Deflection Board
(78660-60180)
3.3.8
CRT Deflection Board
—
(78660-60190)
Clock/Heat Rate Adj.
3.3.9
A7-R40
V Ref Adj
Real Time Clock/Heart
Rate Board
(78660-60260)
Real Time Clock
3.3.10
A7-C9
Rate Freq. Adj.
Real Time Clock/Heart
Rate Board
(78660-60260)
CMR Notch Filter
3.3.11
A4-S1-S8
Setting
(78660-60140)
V Ref, Defibrillator
Charger Board Adj.
3.3.12
Output Energy
3.3.13
A11-R132
Defibrillator Charger
(78670-60120)
A10-R72
Defibrillator Control
(78660-60195)
Calibration
H.V. Charge Time Adj.
ECG Digital Board
3.3.14
A11-R34
Board
Defibrillator Charger
(78660-60120)
Self Test Accuracy Adj.
(also determines
3.3.15
A11-R10
Defibrillator Charger
(78660-60120)
print out accuracy)
Recorder Pen Heat Adj.
3.3.16
—
Recorder
Recorder Stylus Pressure
3.3.17
—
Recorder
Recorder Pen Positioning
3.3.18
—
Recorder
Print Head Adjustment
3.3.19
—
Recorder Controls
Setting Real Time Clock
3.3.20
—
External Controls
#^
3-19
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.3.4
Paddle Contact Indicator Adjustment (A3-R91)
R91 is located on the ECG Analog Board (78670-60155-A3)
3.3.4.1
Equipment Required:
Reference Resistor 64.9 ohms, 1%
3.3.4.2
1.
Procedure:
Connect
the
resistor
between the
paddle
electrodes.
A
good
electrical
connection is essential.
2. Adjust R91 until all the light bars on the Sternum Paddle Contact Indicator are
just lit. Try to find the threshold at which the last two bars have equal
brightness.
1 u u—•
R91 '<
'
:
CRT
^"^
TOP SECTION
3-20
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A(78671A
78670A-l
#^
3.3.5
Low Voltage Power Supply Adjustments (A12-R14, A12-R28)
Adjust the 5V Supply Voltage to 5.1
± 0.05V (R14).
Adjust the 12V Supply Voltage to 12.0
3.3.5.1
± 0.1V (R28).
Equipment Required:
Digital Voltmeter (DVM): Accuracy 0.1%.
(Recommend HP 3466A).
NOTE: Other supply voltages are tightly coupled therefore indirectly regulated
by the 5V Supply. If after adjusting the 5V, the other voltages are incorrect,
consult the troubleshooting section.
3.3.5.2
Procedure:
1. Remove the five nuts that secure the power supply board to the lower case.
Lift and turn the board over to access the component side. Assure it will not
contact other conductive parts.
2.
Put the negative DVM probe on TP4.
3.
With the positive probe on P23 - pin 1, adjust R14 for 5.1
± 0.05V.
4. With the positive DVM probe on P23 - pin 7, adjust R28 for 12.0 ± 0.1V. If
it is necessary to adjust the 12V supply, the ECG baseline offset voltage should be
checked, (Section 3.3.7) since this will be affected.
5.
Allowable voltage deviation of the supplies is shown below:
P23
SUPPLY
PIN NO.
*Measure at CRT anode.
VOLTAGE RANGE
MAX.
HIN.
+5 adjustable
1
5.05
5.15
+12 adjustable
7
11.96
12.04
+12 fixed
10
11.5
12.5
-12 fixed
5
-11.5
-12.5
n
+15 fixed
3
14.5
15.5
-15 fixed
2
-14.5
-15.5
+200 fixed
9
+180
+210
+5 kV
*
4000
4400
Use 1000 Ma probe.
D
LOW VOLTAGE
POWER SUPPLY
78660-60110
(12V) R28
PIN 1
TP4 •
GND
(5V) R14
o
(A12)
P23
BOTTOM SECTION
78660-60110
3-21
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670Af78671A
78670A-1
3.3.6
ECG Cal Adjustment (A3-R72).
Adjusts the CAL reference
Board 78670-60155 (A3)
for 1 mV.
Adjustment located
on the
ECG Analog
3.3.6.1
Equipment Required:
Oscilloscope
Display:
Storage/Variable Persistance Desirable
Time Base:
1 sec./Div. Range included
Vert. Deflection:
Includes 0.5V/Div. range. Accuracy, 0.5%
Function Generator
5-10 Hz, 0.5V pp Capability
Recommend HP 3310A/B
NOTE: There is some interaction between the ECG CAL adjustment and the ECG baseline
offset adjustment. Adjust in conjunction.
1. Determine the exact gain of the highest auto gain stage.
This is done by
inputting a very small ECG signal and measuring the output.
(With small or no
signal present the auto gain is automatically set at maximum).
2.
Connect the equipment as shown in Figure 3-11.
3. Carefully set the function generator at 0.5 V p-p, 5 Hz, as measured on a
calibrated oscilloscope. This applies 0.5 mV p-p to the ECG input. Call this VI.
4. Measure the voltage at
approximately 1.25 V p-p.
the IV ECG
output jack.
Call
5.
The gain of the maximum auto gain stage is G=V2/V1.
6.
Now set the oscilloscope controls:
7.
(1)
Vertical sensitivity
(2)
Time Base
(3)
Positioning
(4)
Triggering
free run
(5)
Mode
storage
As the
trace moves across the CRT
this V2 which
will be
0.5 V/div
1 sec/div
On graticle line at bottom of screen
screen, press the CAL
leading edge of the deflection on the oscilloscope.
button.
This voltage is V3.
Measure the
Calculate
the calibration amplitude thus:
Cal Amplitude = V3/G
8.
The CAL step amplitude should be 0.95 to
necessary.
3-22
1.05 mV.
Adjust the CAL ADJ.
R72 if
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
f*^
Cali bration Si
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R72
CRT
-
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TOP SECTION
Alternate method for Adjusting R72 (Cal)
Note: Since the recorder is required, this method will not work for the 78671A
(delete recorder option).
Use the test equipment listed previously.
Connect as shown in Figure 3-12B on
page 3-40.
1. Connect the oscilloscope to the function generator output. Set the function
generator for 10 Hz sine wave, one volt p-p output as measured on the oscilloscope.
Do not change this setting. This will apply a 1 millivolt p-p signal to the ECG
input.
2.
Place
the ECG Size
control in the AUTO
position (fully clockwise).
Set the
recorder switch to RUN.
3. Allow the unit to run until the display stabilizes, then briefly press the CAL
switch. If the internal switches are in the delay position, it will be about 4
seconds until the CAL signal appears on the recorder chart.
4.
After the CAL
signal appears, it will be several
seconds until
the display
stabilizes.
5. Lay a straight edge along the top of the 10 Hz waveform on the chart. If the
CAL is correctly adjusted, the bottom of the area where the CAL switch was pressed
should just meet the top of the 10 Hz sine wave.
6.
If the CAL signal does not agree with the description in step 5, adjust R72 and
repeat steps 3, 4 and 5 until the correct results are obtained.
3-23
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-l
Explanation:
When the CAL switch is pressed, a 1 millivolt DC
signal is applied causing the
baseline to shift in the positive direction, The 10 Hz signal is superimposed on
the shifted baseline.
If the CAL switch is held for more than a few cycles, the
AUTO baseline circuit will shift the entire display downward to center it on the
CRT and recorder.
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3.3.7
ECG Amplifier Baseline Offset Adjustment (A3-R73)
Adjust the Baseline Offset for no trace movement between MIN and MAX settings of
the ECG
SIZE control.
The baseline
adjust is
located on the Analoq
ECG Board
78670-60155 (A3).
3.3.7.1
Equipment Required:
Oscilloscope helpful but not required.
NOTE 1: The +12V supply voltage affects the baseline offset.
Check and adjust
the 12V supply, if required, before adjusting the baseline offset (Section 3.3.5).
NOTE 2: There is some interaction between
adjustment. Adjust in conjunction.
1.
ECG baseline
offset and
ECG CAL
If an oscilloscope is used, connect to the IV ECG output jack.
2. Turn the ECG SIZE control through its full range from minimum to maximum gain,
noting any vertical movement of the trace. (If using an oscilloscope, free run the
sweep and adjust the vertical sensitivity for good definition of any offset
voltage.)
3. Adjust the zero offset, R73, until less than 40mV voltage change on the
oscilloscope or no discernible movement on the defibrillator monitor is observed,
while turning the ECG SIZE control from MIN to MAX gain.
'
'
•
1
R73
1
1
1
•
r
~CRT
TOP SECTION
3-24
SECTION III • CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-1
f^
3.3.8
CRT Display Adjustments
Includes the CRT beam positioning and
Circuit Board 78660-60180 (A6).
brightness adjustments
on the
Deflection
3.3.8.1
Equipment Required:
Digital Voltmeter:
Capable of 3% accuracy (on complex waveform) at 0.5 VAC
Recommend HP 3466A
3.3.8.2
1.
Procedure:
Brightness Adjustments (A6-R26, A6-R25)
A.
Connect the voltmeter to TPl and TP2 on the deflection board A6.
See
Figure 6-6.
B.
Turn the
located under
INTENSITY
the accessory
control fully
door on top
counter-clockwise.
of the
instrument.
This control
Adjust
is
the MINIMUM
BRIGHTNESS trimmer A6-R26 until the CRT trace is visible.
C.
Turn the INTENSITY CONTROL fully clockwise.
Adjust the MAXIMUM BRIGHTNESS
trimmer A6-R25 for a meter indication of 0.33 volts.
D.
Disconnect the meter.
Rotate the INTENSITY CONTROL from MINIMUM to
MAXIMUM BRIGHTNESS, noting that the trace does not completely extinguish and does
not get so bright that the trace shrinks from the sides of the CRT.
2. Vertical Gain Adjustment (A6-R1)
Place the instrument in the service mode.
(Pull the BEEPER switch up. Turn the
instrument off. Turn the instrument on and quickly push the BEEPER switch down).
A ramp-step waveform should appear on the CRT. Adjust the vertical potentiometer,
Rl, until the steps are each 1 cm in height. Note the graticule marks on either
side of the CRT are 1 cm apart.
3. Horizontal Gain Adjustment (A6-R2)
Turn the instrument on, switch to LEADS input without the leadset plugged in.
Allow the instrument to warm up for a minute or so. Adjust the horizontal gain
potentiometer, R2, until the beam on the CRT just extends to the edges of the
screen. Some adjustment of the beam centering may also be necessary.
4.
Beam Centering
Two ring magnets are placed around the rear of the deflection yoke to center the
beam vertically and horizontally.
Tabs are provided on the ring magnets to
facilitate rotation. Before moving them, make the horizontal gain adjustment.
Note that a great amount of interaction takes place but attempt to center the
vertical while making the horizontal edges of the beam just hit the sides of the
CRT. Readjustment of the horizontal gain and vertical gain may be necessary.
•
o
BEAM CENTERING
j/ADJUST RINGS
TOP SECTION
3-25
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
'^I
3.3.9
Real Time Clock/Heart Rate V Ref Adjustment (A7-R40)
Adjusts the reference voltage.
supply fluctuations.
This voltage effects the circuits
immunity to +5V
Adjustment location is on 78660-60260 (A7).
NOTE: This adjustment is set at the factory and normally should not require
attention.
However, if components associated with this circuit are replaced,
connect the test equipment as described and adjust if necessary.
3.3.9.1
Equipment Required:
Digital Voltmeter
Recommend Hp 3466A
Accuracy 0.05% at 2.49V
Extender Board (2) x 12 pin
HP 78304-60260 or other suitable board.
3.3.9.2
Procedure:
1.
Connect the Voltmeter between TP3 (low side) and TP2.
2.
Adjust R40 to attain 2.490 VDC.
/*^%
TP3
TP2
R40
78660-60260
TOP SECTION
3-26
^
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-1
f^ 3.3.10
Real Time Clock/Heart Rate Frequency Adjustments (A7-C9)
Check/adjust the basic clock frequency which controls the Real Time Clock.Adjustment
location is on the Clock/Heart Rate Board 78660-60260. (A7).
NOTE: This adjustment is set at the factory and normally should not require
attention. However, if components associated with this circuit are replaced,
connect the test equipment as described and adjust if necessary.
3.3.10.1
Equipment Required:
Counter
Accuracy: +0.005 Hz at 2048.00 Hz
(Recommend HP 5314A
with Option 001)
Extender Board (2) x 12 pin
HP 78304-60260 or other suitable board
3.3.10.2
Procedure:
1.
Connect the counter between TP3 (low side) and TPl.
2.
Leave the monitor ON, press the recorder PUSH TO MARK button once.
3.
Set the controls on the counter to read the divided down test frequency.
4.
Adjust C9 if necessary until the counter reads 2048.00 Hz.
TP3
78660-60260
TOP SECTION
3-27
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.3.11
s^k
Common Mode Rejection Notch Filter Switches (A4, Sl-8)
Selects the power line frequency to be rejected or switches the
completely. Located on the Digital ECG Board 78660-60140 (A4).
3.3.11.1
1.
Notch Filter out
Procedure:
Set the miniature switch cluster SI through S8 as shown below:
DESIRED
CONDITION
SI
S2
S3
S4
S5
S6
S7
S8
50
0
X
X
C
0
0
0
0
60
C
X
X
C
C
C
C
C
No Notch
C
X
X
0
C
C
C
C
No Notch
0
X
X
0
0
0
0
0
Code:
0 = Open
C = Closed
X = No Effect - Either Position
•
S1-S8
TOP SECTION
NOTE: This adjustment is set at the factory and normally should not require
attention. However, if components associated with this circuit are replaced,
connect the test equipment as described and adjust if necessary.
3-28
SECTION III-CHECKSAND ADJUSTMENTS
Models 78670A/78671A
f^
78670A-4
3.3.12
Voltage Reference, Defibrillator Charger Circuit Board (A11-R132)
Adjusts the voltage reference used for low battery shutdown of the high voltage
charging circuits.
Adjustment is located on 78670-60120 (All) defibrillator
charger board.
NOTE: This adjustment is set at the factory and normally should not require
attention. However, if components associated with this circuit are replaced,
connect the test equipment as described and adjust if necessary.
3.3.12.1
Digital Voltmeter
Capable of 0.1% accuracy at
Recommend HP 3466A
140 mV and 5.4 V
3.3.12.2
1.
Equipment Required:
Procedure:
Disconnect power from the defibrillator.
2. Remove the five nuts holding the Low Voltage Power Supply Circuit Board in
place; lift it up and in a position to avoid electrical contact with other parts.
3. Connect voltmeter between TP5 and ground. The voltage should be between 5.29 to 5.51V
(5.4 + 2%); adjust R132 as necessary.
TP5
R132
£_
BOTTOM SECTION
3-29
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.3.13
Defibrillator Output Energy Calibration (A10-R72)
Adjust the output energy delivered upon discharge.
Defibrillator Control Board 78670-60195 (A10).
3.3.13.1
Adjustment location
is on the
Equipment Required:
Energy Meter
Recommend Dempsey 429/428A,B
Capable of 5 to 400 Joule
measurements with critically
damped sinusoidal waveform.
± 2% of Full Scale Accuracy
Load Resistance 50ft
3.3.13.2
1.
±
0.5%
Procedure:
Set the ENERGY SELECT Control to 100 Joules.
2. Place the paddles in contact with the energy meter contacts, press the CHARGE
button and after CHARGE DONE indicator lights press both DISCHARGE switches.
3.
Adjust the V adjust, R72,
if necessary to obtain
4.
Set the ENERGY SELECT control to 360 Joules.
proper delivered
energy.
/^
5. Charge and discharge the defibrillator into the energy meter and again make
adjustments with the V adjust, R72 until the energy delivered matches the energy
select switch setting.
6.
Check the lower settings to confirm they are meeting specifications of +15% or
4 Joules (whichever is greater).
7.
If an adjustment is required, the H.V.
charge time adjust and self-test
accuracy tests should be performed.
R72
r-^
<-J1
3
=
oD
1
1
.
1
1
CRT
TOP SECTION
3-30
SECTION III- CHECKS ANDADJUSTMENTS
Models 78670A/78671A
78670A-1
(^ 3.3.14 High Voltage Charge Time Adjust (A11-R34)
Sets the charging rate of the high voltage defibrillator capacitor. Adjustment
located on the Defibrillator Charger Board 78670-60120 (All).
3.3.14.1
Equipment Required:
Fully charged battery
HP 78660-60401
(of known good condition)
OR
Power Base
Model
78668A
(A-C input must be 110 to 120V)
Stopwatch or other timer
NOTE: Energy Accuracy must be within specification before making this test.
Refer to Section 3.3.13, Defibrillator Output Energy Calibration.
3.3.14.2
Procedure:
1.
Set the ENERGY SELECT Control to 360 J.
2.
Time the interval
between pressing the CHARGE button and when the CHARGE DONE
indicator lights.
3.
This interval should be as shown below:
ENERGY
SETTING
360
ALLOWABLE CHARGE TIME
BATTERY
POWER BASE
8-10 sec
6-8 sec
R34
cC
BOTTOM SECTION
4.
Adjust R34 to change the charge time.
When adjusting, set
to a median of the
allowable range.
3-31
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-l
3.3.15
Self Test Accuracy Adjust (A11-R10)
Set the I PEAK adjustment for self test mode accuracy. This also determines the
accuracy of the delivered energy printout information on the recorder.
The
adjustment is located on the Defibrillator Charger C.B.
NOTE 1: The Energy
78670-60120 (All).
Accuracy Calibration Check must be made
before this check
and adjusted if necessary.
NOTE 2: To avoid overheating of the internal 50 ohm test resistors with
consequent inaccuracies of the derived information, do not exceed the equivalent of
three 360 Joule discharges/min.
NOTE 3: If the defibrillator has a strip chart recorder, the discharge energy
will be printed on the strip chart.
3.3.15.1
Procedure:
1. Place the instrument in the Service Mode (pull the BEEPER VOLUME switch up,
turn the instrument off. Turn the instrument on and quickly push the BEEPER VOLUME
switch down). The CRT will display a step/ramp deflection.
2.
Place the paddles in their storage pockets.
3.
Set the ENERGY SELECT to 100 Joules. Charge and discharge the defibrillator.
4.
Adjust the
I PEAK potentiometer R10 to obtain a reading of 100 Joules on the
LCD display with successive discharges.
5. Set the ENERGY SELECT to 360 Joules and with further charge/discharge cycles,
readjust R10 for a 360 Joule reading on the LCD display.
6. Return ENERGY SELECT to 100 Joule position and recheck the discharge reading.
It should read between 90 and 110 Joules.
R10
BOTTOM SECTION
3-32
SECTION III • CHECKS AND ADJUSTMENTS
Models 78670A178671'A
78670A-1
3.3.16
Recorder Pen Heat Adjust
Adjusts the darkness of the chart recording line.
3.3.16.1
Equipment Required:
Adjustment tool
HP 78660-27800
OR
screwdriver
3.3.16.2
Common type, 0.1 in. blade, blade
length 5 in. min.
Procedure:
1. Access to the adjustment is along the right (stylus side) of the enclosure near
the top. (See below)
2.
Adjust for desired writing qualities.
3. The pen heat time is specified for less than 1.5 seconds.
1 minute for the pen to cool, then check for pen heat time.
signal applied such as Service Mode.)
After adjusting give
(Best done with some
^
_PEI\!
HEAT
PEN
POSITION
3-33
SECTION HI - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
786 70A-1
3.3.17
Recorder Stylus Contact Pressure Adjustment
Adjusts the stylus/paper contact pressure.
3.3.17.1
Equipment Required:
Pressure Gauge
HP 8750-0345
5/64" Hex Driver
HP 8710-1196
Slide the pressure gauge under the stylus tip. Move the
the right; when there is a slight gap between the stylus
pressure gauge slowly to
and recorder paper, read
the pressure gauge indication.
MOUNTING SCREW
STYLUS PRESSURE
MOUNTING SCREW
,.1
100 .K
Correct stylus pressure is 6.0 +2 grans. If necessary, adjust the pressure screw
on the stylus plate so that the gauge reading is approximately 6.0 t 2 grains.
3-34
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
786 70A-1
3.3.18
Recorder Pen Positioning
Adjusts centering of trace with no signal applied.
3.3.18.1
Equipment Needed
Adjustment tool
HP 78660-27800
OR
Screwdriver
3.3.18.2
1.
Procedure:
Access to the adjustment is along the right (stylus side) of the enclosure near
the bottom.
2.
Common Type, 0.1 in. blade width
5 in. min blade length
See Figure below.
Switch the ECG
SOURCE to LEADS position.
Turn ECG
SIZE control fully counter
clockwise.
3.
Observe the stylus position while the Recorder is running.
4.
Adjust the
pen positioning to the
chart center while the
recorder is running
and the paddles are shorted.
PEN
HEAT
N
POSITION
3-35
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670 A178671A
78670A-1
3.3.19
Recorder Print Head Adjustment
The thermal printhead operates by heating resistive elements
ceramic head assembly.
It produces square dots.
The thermal dots
positioned approximately
forward
end of
are
the ceramic
substrate.
Make
.05 inches
an initial
contained within the
(1.25 mm) after the
adjustment visually
by
adjusting printhead to place the dots over the paper contact point.
This
adjustment is usually close enough to produce printing when the recorder is first
turned on and reduces the time required for full adjustment.
3.3.19.1
3.3.19.2
Equipment Required:
Hex driver 3/32"
HP 8710-0523
8-10 x magnifier
useful for examining dot clarity
Procedure:
1. Turn the instrument on and press the mark switch.
to print the time and date.
2.
This will cause the recorder
Examine the printout with an 8 to lOx magnifier, for uniformity of dots.
3. If the dots get lighter on the trailing edge, the printhead is too far back and
must be moved forward. If the dots are light on the leading edge and get darker at
the trailing edge, the printhead is too far forward and must be moved back.
4.
Turn the printhead
adjustment screw (shown in figure below)
the printhead back or counter-clockwise to move
one
half
to
one turn
for
coarse
it forward.
adjustments
or
clockwise to move
DO NOT turn more than
one quarter
turn
for
fine
adjustments at a time.
5.
Move the
printhead in
the required
direction and
obtain another
Continue the process until the dots are of uniform density.
MOUNTING SCREW
STYLUS PRESSURE
MOUNTING SCREW
3-36
printout.
SECTION III- CHECKSAND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.3.20
3.3.20.1
1.
Setting Real Time Clock
Procedure:
Turn BEEPER
VOLUME
up beyond minimum level.
(Knob in inside accessories
compartment on top of instrument).
2.
Pull BEEPER VOLUME switch up to "Service" position.
3.
Turn ENERGY SELECT switch to "OFF" position (power off).
4.
Press and hold PUSH TO MARK switch with left hand.
5. Using right hand, turn ENERGY SELECT
quickly push BEEPER VOLUME switch to the
switch to "monitor" (ON) position and
down position when the beeper tone is
heard.
6.
j0\
Don't release the PUSH TO MARK switch until after 5 seconds.
7. After the CRT is warmed up (within
appear on the display.
15 seconds)
a three digit
NOTE: If the unit is not displaying the three digits, turn
repeat steps 2 through 6.
number should
off the power and
8. The "1" indicates that the unit is in a time set routine and is ready to accept
a change of date. The date of the month currently set is displayed as the two
digits behind the "1".
NOTE: If the information displayed in this or the following steps (date, month
or etc.) is already correct and no change is desired, proceed to the following step
by pressing the PUSH TO MARK switch.
9. To change the date; press and hold the RECORDER switch until the date displayed
is correct. When it is correct, release the RECORDER switch and press the PUSH TO
MARK switch.
NOTE: The first digit will now increment to
a "2" indicating that the unit is
now ready to accept changes to the month.
10. To change the month, press and hold the RECORDER switch until the numerical
equivalent of the correct month is displayed (e.g. "9" will cause the month of
September to be set as the correct month, and printed out on the annotating
recorder during run cycles).
11.
^
When the correct month is displayed, release the RECORDER switch and press the
PUSH TO MARK switch.
NOTE: The first digit will now increment to
a "3" indicating that the unit is
now ready to accept changes to the hour of the day.
3-37
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
12. To change the hour of the day; press and hold the RECORDER switch until the
correct hour is displayed in "24 hour clock format" (e.g.
09 is the equivalent of
9 AM, and 21 is the equivalent of 9 PM).
13.
When the correct hour is displayed,
release the RECORDER switch and press the
PUSH TO MARK switch.
NOTE: The first digit will now increment to a "4" indicating that the unit is
now ready to accept changes to the minutes.
14.
To change
the minutes, press and
hold the RECORDER switch
until the correct
minutes are displayed.
15.
When the correct minutes are displayed,
release the RECORDER switch and press
the PUSH TO MARK switch.
If all changes have been made correctly, the new date/time values are now loaded
into the memory of the unit, and can be verified by pressing the PUSH TO MARK
switch which will run the recorder and print out the day, date, and time of day as
well as a marker
NOTE: If
I .
the entire
process is
not followed,
i.e., all
steps accomplished
through the minutes segment, the unit will assume that the date/time setting
sequence is aborted and revert to the day, date, time stored in memory prior to
entering the date/time setting routine.
16.
Turn unit OFF to get out of the time set mode.
/m%
r^^K
3-38
SECTIONIII - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
3.4
SPECIFICATION CHECKS
3.4.1
ECG Amplifier/Heart Rate Section
3.4.1.1
Test Equipment.
Required test equipment
for
performing ECG Amplifier/Heart
Rate specification
checks are listed in Table 3-4.
TABLE 3-4
TEST EQUIPMENT REQUIREMENTS
FOR ECG AMPLIFIER/HEART RATE SPECIFICATION CHECKS
REQUIREMENT
NECESSARY QUALIFICATIONS
FUNCTION GENERATOR
Recommend:* HP 3310A/B
OSCILLOSCOPE
Recommend:
HP 1741A or
HP 181A with 1801A
and 1820C plug-ins
Output level: 30 V pp Open Circuit
Frequency Range: 0.25 to 60 Hz.
Frequency Response: 1% (sine wave)
Output Waveforms: Sine, Square
Display:
Storage/Variable Persistence
Bandwidth:
d-c to 10 MHz.
Vert. Deflection Range: 20 mV to 10 V/div
Storage Write Speed: 5 cm//i sec minimum
Mode: 2 Channel, chopped
D-C POWER SUPPLY
Recommend:
HP 6214 or HP 6224B
Output:
ECG GENERATOR/CALIBRATOR
Output Level:
Recommend:
Range:
Parke-Davis
10 V, regulated; 15 MA.
1 mV
60 and 120 BPM calibrated outputs
3175
DIGITAL VOLTMETER
Recommend:
HP 3466A
Capable of 300 mV DC + 1%
measurements
TEST CABLES/COMPONENTS
Recommend:
(1) HP 11086A
BNC-BNC Cable
(2) HP 10501
BNC-Clipleads Cable (Alligator Clips must
be added—4 required).
(1)
(1)
(3)
(1)
(1)
HP 0757-0465
HP 0757-0401
HP 0698-3159
HP 0757-1094
HP 0160-3552
100 K ±1% Resistor.
100 a ±1% Resistor.
1
HP 0757-0438
(2) HP 0757-0442
(1)
(1)
(1)
(1)
(1)
(1)
(1)
1
HP 8120-3164
HP 1251-7127
HP 14489B
HP 14151A
HP 14445A
HP 0160-4511
Hp 0698-5552
(1) HP
0698-6366
26 K
1.5 K
Resistor.
Resistor.
1 uF Capacitor.
5 K Resistor.
10 K Resistor.
Signal Cable, ECG Output
Coaxial Adaptor, BNC to Phone Jack
Patient Cable
Electrode Lead Set
ECG Electrodes
220 pF Capacitor.
1 K Resistor.
800 ft Resistor.
3-39
SECTIONIII - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
786 70A-1
3.4.1.2
ECG Amplifier Gain - Manual Control.
This check verifies that the gain range of the ECG amplifier is adjustable from 250
to 3600.
Section V.
1.
If this
check fails, refer
to the
ECG troubleshooting
information in
Perform the check as follows:
Connect the test equipment as shown in Figure 3-12A.
SYNC 1000:1 CABLE
14482A
3310A/B
FUNCTION
GENERATOR
©
ADAPTER
1251-7127
11086A
1220
OSCILLOSCOPE
ADAPTER
1251-7127
o
ECG OUTPUT
CABLE 8120-3164
11086A
Figure 3-12A. ECG Amplifier Gain and Frequency Response Test Setup.
1
SYNC 1000:1 CABLE
14482A
3310A/B
FUNCTION
GENERATOR
ADAPTER
1251-7127
11086A
1220
OSCILLOSCOPE
11086A
Figure 3-12B. ECG Amplifier Gain and Frequency Response Test Setup.
2.
Set the defibrillator controls as follows:
(a) ECG SOURCE Control - LEADS I position.
(b) ECG SIZE Control - Fully clockwise, but not past the "AUTO" detent.
(c) INTENSITY Accessory Compartment - To obtain adequate viewing level.
3.
Adjust the test equipment as follows:
(a)
Function Generator
Frequency
- 5 Hz.
Function
3-40
- Sine Wave
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-l
Output Level
1 V p-p (measure with the oscilloscope
at the output of the function generator
while the function generator is con
nected to the 1000:1 divider circuit.
Then reconnect the oscilloscope as
shown in Figure 3-12A.
(b)
Oscilloscope Channel A
Vertical Sensitivity - 1 V/i
, cm
Time Base
- 50 ms/cm
m:
4. A setting of the ECG SIZE control to the full clockwise position should provide
an overall gain of at least 3600. The 1 mV sine wave signal at the input of the
defibrillator should produce greater than 3.6 V p-p when measured on the IV ECG
output connector of the defibrillator.
5.
Rotate the ECG SIZE control to the full counterclockwise position,
whether smooth change of amplitude occurs on the oscilloscope.
noting
6. Change the oscilloscope vertical sensitivity to 0.05 V/cm. Observe the sine
wave display on the oscilloscope.
The signal amplitude should be 250 mV p-p or
less.
3.4.1.3
ECG Amplifier Gain - Auto Mode
1.
Connect the test equipment as shown in Figure 3-12A.
2.
Set the defibrillator ECG SIZE control to the AUTO position, ECG SOURCE to LEADS
I position.
3.
Adjust the test equipment as follows:
(a) Function Generator
Frequency
- 5 Hz.
Function
- Sine Wave
Output Level - 0.5V p-p (measure with the oscilloscope at the
output of the function generator while the
function generator is connected to the
1000:1 divider circuit.
Then reconnect
the oscilloscope as shown in Figure 3-12.
(b) Oscilloscope
Vertical Sensitivity - 0.1 V/cm at start
Time Base
4.
- 50 ms/cm
Connect Channel B of the oscilloscope to the function generator (Determine that
the channel A and B deflections are equal).
5. Start with a function generator output of 0.5 V pp (0.5 mV ECG input). Confirm
that the CRT display or recorder shows between 0.8 and 1.6 cm amplitude sine wave.
6.
Increase the function generator amplitude slowly and watch the display go
through four discrete gain changes (5 stages including the starting stage). Keep
increasing amplitude until the display just goes over 3.2 cm pp. Input should now
be 5.1 V ±20% on the function generator (5.1 mV
±20% at ECG Input).
3-41
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
7.
Decrease amplitude slowly and watch the display go back through four discrete
gain changes.
NOTE: It takes 2 seconds for the AUTO
in signal level.
GAIN circuitry to respond to a decrease
8. Continue decreasing amplitude until the display is just below 1.6 cm p-p for 2
seconds. Function generator input should now be 0.64 V p-p ±20%.
3.4.1.4
Baseline Offset - ECG Lead Input
1.
Connect the test equipment as shown in Figure 3-13.
2.
Place the ECG source switch in LEADS I position.
SHORT
PATIENT CABLE
14489B
INPUTS
-a
DIGITAL
VOLTMETER
CD—,
OS01A
f
Figure 3-13. ECG Amplifier Baseline Offset (Leads).
3.
Turn the ECG SIZE control from MIN
to MAX position while observing the digital
voltmeter.
4.
The voltmeter
should not change more than 300 mV «A300mV)from MIN to MAX gain
with all three input leads shorted together.
3.4.1.5
Baseline Offset - Paddles Input
Perform the check as follows:
1.
Remove the cable from the ECG input connector and connect the test equipment as
shown in Figure 3-14.
DIGITAL
VOLTMETER
O
8120-3164
10501A
Figure 3-14. ECG Amplifier Baseline Offset (Paddles).
3-42
SECTION III -CHECKS AND ADJUSTMENTS
Models 78670A/78671A
2.
Switch the ECG source switch to the PADDLES position.
3.
With the paddles pressed firmly together, vary the ECG SIZE control from MIN to
MAX.
The reading on the DVM should not vary more than 300 millivolts.
3.4.1.6
ECG Amplifier Frequency Response, Leads Input
Perform the check as follows:
1.
Connect the test equipment as shown in Figure 3-12A.
2.
Adjust the test equipment as follows:
(a) Function Generator
Frequency
- 5 Hz.
Function
- Sine Wave
Output Level - IV p-p
(b) Oscilloscope
Vertical Sensitivity - 0.2 V/cm
Time Base
3.
- 50 ms/cm
Set the ECG SOURCE Switch to LEADS I position.
4. Set the ECG SIZE control to obtain a 5 cm deflection on the oscilloscope (1 V
p-p). The defibrillator CRT display should have 1 cm deflection, if not, refer to
r t h e Adjustment part of this section, and adjust accordingly.
Use a short length of
chart paper for measurement.
5.
Change the function generator to 0.5 Hz.
6. Observe the oscilloscope for a minimum deflection of 3.5 cm.
(3dB down).
The
CRT display should not be less than 0.7 cm.
7. Slowly increase the
peak-to-peak deflection
function generator frequency to 40 Hz while observing the
on the oscilloscope and the CRT display.
The deflection
should remain greater than 3.5 cm on the oscilloscope and 0.7 cm on the CRT
display.
NOTE: If the defibrillator
is equipped with a recorder, refer to 3.4.2.
recorder frequency response tests (since the test set-up is the same).
3.4.1.7
^
*
ECG Amplifier Frequency Response Check - Paddle Input
1.
Switch the ECG SOURCE to PADDLES.
2.
Connect the test equipment as shown in Figure 3-15.
3.
Adjust the test equipment as follows:
(a)
for
Function Generator
Frequency
- 5 Hz.
Function
- Sine Wave
Output Level - 1 V p-p
(b) Oscilloscope
Vertical Sensitivity - 0.2 V/cm
Time Base
- 50 ms/cm
3-43
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670Aj78671A
78670A-l
DEFIBRILLATOR
3310A/B
FUNCTION
GENERATOR
1000:1
DIVIDER
r--_—I
®
•y
10501A
OSCILLOSCOPE
ADAPTER
o
1251-7127
r
11086A
8120-3164
Figure 3-15. ECG Amplifier Frequency Response Setup (Paddles).
4.
Perform steps 3 through 6 of 3.4.1.6.
3.4.1.8
Input Offset Tolerance (DC) - ECG LEAD INPUT.
/*\
1.
Connect the test equipment as shown in Figure 3-16.
ECG
DEFIBRILLATOR
IN
14489B
PATIENT CABLE
POWER
SUPPLY
3310A/B
FUNCTION
GENERATOR
©
1
OSCILLOSCOPE
ADAPTER
1251-7127
8120-3164
o
11086A
Figure 3-16. Input Offset Tolerance (DC) Leads Test Setup.
3-44
JJ
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
786 70A-1
2.
Adjust the test equipment as follows:
(a)
Function Generator
Frequency
- 5 Hz.
Function
- Sine Wave
Output Level - 1 V p-p measured using oscilloscope
(b)
Power Supply
Output Level - 10.0 volts measured using an oscilloscope.
(c)
Oscilloscope
Time Base
- 50 ms/cm
Vertical Sensitivity - As necessary for set-up
0.2 V/cm for measurement
3.
With the
power supply connected but
turned off, adjust the
defibrillator ECG
SIZE control for a 1 cm p-p waveform on the defibrillator display.
4. Turn the power supply on. After approximately 10 seconds, the sine wave viewed
on the oscilloscope should show no evidence of clipping and the amplitude should
not be reduced by more than 20%.
5.
Reverse the polarity of power supply inputs to the test circuit (negative to
the 800 ft resistor, positive to bottom of the 100 ft resistor).
6.
The sine wave viewed on the oscilloscope should conform to step 4 above.
3.4.1.9
Input Offset Tolerance (DC) - Paddle input
1. Connect the test equipment as shown in Figure 3-16.
Instead of connecting to
the ECG INPUT, connect to the paddles as shown in Figure 3-15.
2.
Adjust the test equipment as follows:
(a)
Function Generator
Frequency
- 5 Hz.
Function
- Sine Wave
Output Level - 1 V p-p measured using oscilloscope
(b)
Power Supply
Output Level - 10.0 volts measured using an oscilloscope
3. With the positive terminal connected but turned off, adjust the defibrillator
ECG SIZE control for a 1 centimeter p-p waveform on the defibrillator display.
4. Turn the power supply on. The sine wave viewed on the oscilloscope should
conform to 3.4.1.8, step 4.
5. Reverse the polarity of the power supply inputs to the test circuit (negative
to the 800 ft resistor, positive to bottom of the 100 ft resistor.
6.
The sine wave viewed on the oscilloscope should conform to 3.4.1.8, step 4-5.
3-45
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670AJ78671A
78670A-1
3.4.1.10
ECG Amplifier Noise, Leads Input
This procedure checks the maximum allowable ECG Amplifier noise referred
input. First the ECG Amplifier Gain is set at 4000 as follows:
1.
Connect the test equipment as shown in Figure 3-12A.
2.
Adjust the test equipment as follows:
(a)
to the
Function Generator
Frequency
- 5 Hz.
Function
- Sine Wave
Output Level - 1 V p-p (measure with the oscilloscope at
the output of the function generator while
the function generator is connected to the
1000:1 divider circuit. Then reconnect the
oscilloscope as shown in Figure 3-12A.
(b)
Oscilloscope Channel A
Vertical Sensitivity - 1 V/cm
Time Base
- 50 ms/cm
,3A.«od^ust
the ?CG SIZE contro1 for 4 V on the oscilloscope (ECG Source switch
LEADS I position).
NOTE: For the remainder of the tests do not change the ECG SIZE control
setting. If unable to get 4000 gain at maximum setting, set to a known lower value
and reduce allowable noise levels proportionly.
4. Connect the equipment as shown in Figure 3-17.
14489B
PATIENT CABLE
1415A
LEAD SET
( TEST CIRCUIT
RA I V 2BK "j
J
L^f\ LA
AAA
-VW-i
26 K
26K
o o ol
|
£0/
| 26K
OSCILLOSCOPE
I
"
A
o
AW-'
I
10501A
I
SHIELDED CASE
ADAPTER
1251-7127
ECG OUTPUT CABLE '
8120-3164
ECG
OUT
' 10501A 1
GND
lOOHz EXTERNAL
LOW-PASS FILTER
Yft ?*
"—v
15K -±^1/jF >
^
Figure 3-17. ECG Amplifier Noise, Leads Input Test Setup.
3-46
*
^
SECTION III- CHECKS AND ADJUSTMENTS
Models 786 70A/786 71A
786 70A-1
5.
6.
Set the oscilloscope controls as follows:
(a)
Vertical Sensitivity
.05 V/div
(b)
Time Base
0.5 sec/div
(c)
Triggering
Free Run
(d)
Mode
Storage
Use
the store function
of the oscilloscope and
adjust the controls
to allow
reading peak to peak excursions without blooming of the trace.
7. The peak to peak noise on the oscilloscope should not exceed 113
corresponds to 10 Vrms referred to the input at the ECG gain of 4000.
NOTE:
The monitor
ECG
NOISE specification
calls
for a 12
dB per
mV which
octave
external filter to simulate the response of an external chart recorder connected to
the ECG output of the monitor. The filter used here is a 6 dB per octave filter
which will yield a slightly higher noise level because of the slower frequency
rolloff, and is hence a more conservative verification of the noise specification
as well as being easier to construct.
3.4.1.11
ECG Amplifier Noise, Paddles Input
This procedure checks the maximum allowable ECG
input using paddles connection as SOURCE.
1.
If not already done, set the ECG Amplifier
2.
Connect the equipment as shown in Figure 3-18.
amplifier noise referred
to the
Gain as in 3.4.1.10, steps 2 and 3.
Put ECG source to paddles.
DEFIBRILLATOR
OSCILLOSCOPE
CJ
<?
I
I v
SHIELDED CASE
ADAPTER
1251-7127
1.5K
8120-3154
VF
:£
r
Figure 3-18. ECG Amplifier Noise, Paddle Input Test Setup.
3-47
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
/-*^.
3.
Follow the same procedure as with LEADS source in steps 5,6 and 7.
The paddles
SOURCE and leads SOURCE noise specification are the same.
3.4.1.12
1.
ECG Calibration Check
Determine
the exact
gain of
the highest auto
gain stage.
This is
applying a very small known ECG signal input and measuring the output.
or no signal present the auto gain is automatically set at maximum).
2.
done by
(With small
Connect the equipment as shown in Figure 3-12A.
3.
Carefully set the function generator at 0.5 V pp, 5 Hz as measured on
calibrated oscilloscope. This puts 0.5 mV p-p to the ECG input. Call this VI.
4.
Measure the
IV ECG output.
Call this
V2, which will be
a
approximately 1.25 V
p-p.
5.
The auto gain will be G = V2/V1.
6.
Now set the oscilloscope controls:
(a)
Vertical sensitivity
0.5 V/div
(b)
Time Base
1 sec/div
(c)
Positioning
(d)
Triggering
(e) Mode
On graticle line at bottom of screen
Free run
Storage
7. As the trace moves across the CRT screen, press the CAL button.
Call the
leading edge deflection voltage V3. Calculate the calibration amplitude thus:
Cal Amplitude = V3/G
Figure 3-19. Calibration Step Waveform.
3-48
/^^%k
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
786 70A-1
8.
The CAL step amplitude should be 0.975 to 1.025 mV. Refer to Section 3.3.6 for
adjustment procedure.
3.4.1.13
This
Common Mode Rejection (CMR) Leads Source
procedure verifies
that the monitor will
rejection of unwanted interference signals with
and 100 dB with the NOTCH FILTER switched out.
provide 112 dB
of common mode
the internal 50/60 Hz NOTCH FILTER
This with up to 5 Kft of electrode
impedance imbalance and using the ECG LEADS source(LEADS I position).
1.
Connect the equipment as shown in Figure 3-12.
2.
Set the function generator controls as follows:
3.
(a)
Frequency
5 Hz
(b)
Output Level
1 V p-p
(c)
Function
Sine Wave
Set the oscilloscope controls as follows:
(a)
Vertical Sensitivity
lV/div
(b)
Time Base
50 ms/div
4. Adjust the defibrillator ECG SIZE control for 4 V p-p on the oscilloscope (4000
gain). Leave this ECG Gain setting for the remainder of the test.
5.
Connect
the equipment
as
shown
in
Figure
3-20, connecting
the
function
generator ground to the defibrillator ground jack (at rear).
14489B
PATIENT CABLE
DEFIBRILLATOR
3310A/B
TEST CIRCUIT
FUNCTION
GENERATOR
©
DIFiBHIlLAfOa UONIIOH
-}
ECG OUTPUT CABLE
8120-3164
OSCILLOSCOPE
ADAPTER
1251-7127
DEFIB GND
o
-y
SHIELDED BOX SHOULD BE
AT A DISTANCE FROM GROUND
TO MINIMIZE CAPACITY TO GROUND.
1 1086A
Figure 3-20. Common Mode Rejection Test Setup (Leads).
3-49
SECTION III • CHECKS AND ADJUSTMENTS
Models 78670A\78671A
78670A-l
6.
Set the function generator controls as follows:
7.
(1)
Frequency
60 Hz (50 Hz if this is the power line frequency
and the Notch Filter is set accordingly)
(2)
Output Level
30 V p-p
(3)
Function
Sine Wave
Set the oscilloscope controls as follows:
(a)
Vertical Sensitivity
0.1 V/div
(b)
Time Base
0.5 sec/div
(c)
Triggering
Line or Free Run
8. With the NOTCH FILTER switched IN, the oscilloscope reading should not exceed
0.30/V p-p (-112 dB).
With the NOTCH FILTER switched OUT, the reading should not
exceed 1.2 V p-p (-100 dB). Recheck with the RA and LA connections reversed. See
Section 3.3.11 for NOTCH FILTER switch location and selection instructions.
NOTE 1: Use the STORE function of the oscilloscope. Adjust controls to allow
reading of the peak to peak excursions without blooming of the trace.
NOTE 2: The NOTCH FILTER switched OUT position can be simulated by using 40 Hz
as a common mode frequency since the FILTER is ineffective at that frequency.
3.4.1.14
This
Common Mode Rejection (CMR), Paddles Source
procedure verifies
that the monitor will
rejection of unwanted interference signals with
and 84 dB with the NOTCH FILTER switched OUT.
provide 104 dB
of common mode
the internal 50/60 Hz NOTCH FILTER
This is with up to 1 Kft of imbalance
between paddle connections.
1.
Set the ECG Amplifier Gain to 4000 as covered in 3.4.1.13, steps 2-4 (ECG SOURCE
in Paddles Position).
2. Connect the equipment
3.4.1.13, steps 6 and 7,
as shown in Figure 3-21 and set the controls as in
except set the oscilloscope vertical sensitivity for
desired viewing amplitude.
3. With
(104dB).
the NOTCH FILTER switched IN the reading should not exceed 0.76 V p-p
With the NOTCH FILTER switched OUT the reading should not exceed 7.57 V
p-p (84dB).
3-50
Recheck the paddle connections reversed.
SECTION III - CHECKS AND ADJUSTMENTS
Models 7S670A/78671A
786 70A-1
DEFIBRILLATOR
3310A/B
TEST CIRCUIT
I
A
I
FUNCTION
1 220pF
1K
I
GENERATOR
Hh
©
1%. w
W .9 .?
f
10501A
ECG OUTPUT CABLE
8120-3164
ADAPTER
OSCILLOSCOPE
1251-7127
a
11086A
r
Figure 3-21. Common Mode Rejection Test Setup (Paddles).
3.4.1.15
1.
Heart Rate Accuracy
Connect the test equipment as shown in Figure 3-22.
14489A
ECG
DEFIBRILLATOR
IN
ECG GENERATOR/
CALIBRATOR
Figure 3-22. Heart Rate Accuracy Test Setup.
2.
Turn the defibrillator ON, ECG SOURCE to LEADS I position.
3.
Turn
the ECG
generator ON and
adjust the defibrillator
ECG SIZE
control to
display 1 cm R-wave deflection on the monitor.
4. Check the heart rate digital display in the calibrated 60 BPM and 120 BPM
switch positions of the ECG Generator.
The heart rate accuracy specification is
± 5% or 2 BPM (whichever is greater).
3.4.1.16
1.
Heart Rate Alarm Limits
Connect the test equipment as shown in Figure 3-12.
3-51
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670AJ78671A
78670A-1
2. Put the function generator on square wave.
Adjust for IV p-p output at 0.5
Hz. Adjust the ECG SIZE control for reliable counting. The circuit counts both
positive and negative going excursions of the square wave, therefore the heart rate
count will be:
Heart rate = frequency setting x 60 x 2 = 60 BPM
3. Turn the ALARM switch ON. Vary the frequency between 30 BPM (0.25 Hz) and 150
BPM (1.25 Hz) the alarm should not sound. Vary the frequency slightly below 0.25
Hz so that the heart rate digits drop below 30.
The alarm should sound and the
recorder should run. Likewise when the heart rate indication exceeds 150 BPM, the
alarm sounds and the recorder starts.
4. Check the alarm delay time from the time the heart rate changes until the alarm
sounds. This should be 3-8 seconds depending on the heart rate average.
3.4.2
Recorder Section
3.4.2.1
Test Equipment Requirements
Test equipment,
for performing recorder specification
checks, is listed
in Table
3-5.
TABLE 3-5
TEST EQUIPMENT REQUIREMENTS FOR RECORDER SPECIFICATION CHECKS
REQUIREMENT
NECESSARY QUALIFICATIONS
FUNCTION GENERATOR
Recommend HP 3310A/B
OSCILLOSCOPE
Recommend:
Output Level: 30 V pp Open Circuit
Frequency Range: 0.25 to 60 Hz
Frequency Response: 1% (sine wave)
Output Waveforms: Sine, Square
Display:
Storage/Variable Persistence
Bandwidth:
HP 1741A or
HP 181A with 1801A
dc to 10 MHz
Vert. Deflection Range: 20 mV to 10 V/div
Storage Write Speed: 5 cm/ju sec minimum
and 1820C plug-ins
ECG GENERATOR/CALIBRATOR
Output Level: 1 mV
Recommend:
Parke-Davis
Range:
60 and 120 BPM calibrated outputs
3175
TEST CABLES/COMPONENTS
Recommend:
(2) HP 11086A
(2) HP 10501
3-52
BNC-BNC Cable
BNC-Clipleads Cable (Alligator Clips must
be added
4 required).
(1) HP 14482A
Sync Cable (1000:1)
(1)
(2)
(2)
(1)
Signal Cable, ECG Output
Coaxial Adaptor, BNC to Phone Jack
HP
HP
HP
HP
8120-3164
1251-7127
14489B
14151A
ECG Cable
Electrode Lead Set
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A178671A
78670A-1
3.4.2.2
Recorder Frequency Response
Perform the check as follows:
1.
Connect the test equipment as shown in Figure 3-12A.
2.
Adjust the test equipment as follows:
(a)
Function Generator
Frequency
- 5 Hz
Function
- Sine Wave
Output Level - 1 V p-p
(b)
Oscilloscope
Vertical Sensitivity - 0.2 V/cm
Time Base
- 50 ms/cm
3. Set the ECG SIZE control to obtain a 5 cm. deflection on the oscilloscope (1 V
p-p). Turn the Recorder ON to RUN. Measure the peak to peak excursion of the sine
waves.
4.
This should be about 10 mm.
Change
the function generator to
If not, consult the Troubleshooting Secton.
0.5 Hz.
Again
run a short strip
of paper.
The minimum allowable deflection is 70.7% of the 5 Hz reference value.
5. Change the function generator to 1 Hz. Run the recorder. Slowly increase the
frequency to 20 Hz. The deflection amplitude should remain between 90 and 110% of
the 5 Hz reference value.
6. Run the recorder while increasing the frequency from 20 Hz to 40 Hz. The
deflection amplitude should remain between 70 and 110% of the 5 Hz reference value.
3.4.2.3
1.
Recorder Gain Accuracy, Linearity, and Overshoot
Place the unit in the Service Mode as follows:
(a) Turn the unit
OFF.
Pull up on the BEEPER
volume control under accessory
door.
(b) Turn the unit ON and quickly push down on the BEEPER volume control.
(c)
The unit
should then
display a test pattern
on the
CRT display,
the
Recorder, and the 1 V ECG V output as shown in Figure 3-23.
Figure 3-23. Service Mode Test Pattern, Recorder.
3-53
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
2. The test pattern includes a series of exact 1 V steps in the positive direction
then the negative direction followed by a positive 2 V step then a negative 2 V
/^%
step.
3. The Gain Accuracy is specified as
negative 1 V step should produce 10 mm
4.
Linearity specification is
40 mm, therefore 0.4
the test pattern.
5.
Carefully examine
±5% at 10 mm therefore the
±0.5 mm (at 25 degrees C).
±1% of full scale.
Full scale is considered to be
mm is the maximum deviation allowable on any
all of
the test
steps for
positive and
overshoot.
of the steps of
Maximum
overshoot
allowed is 10% on any step.
3.4.2.4
Recorder Chart Speed
Perform the check as follows:
1.
Connect the test equipment as shown in Figure 3-12,
except delete the
oscilloscope connections.
2.
Set the function generator exactly on 1 Hz square wave.
3.
Run the recorder and adjust the ECG SIZE control for a viewable trace.
4. There should be one square wave cycle per major division (25 mm) on the chart.
Allowable deviation is
3.4.3
±5% (23.75 to 26.25 mm).
^k
Defibrillator Section
3.4.3.1
Test Equipment.
Test equipment required for performing defibrillator specification checks is listed
in Table 3-6.
TABLE 3-6
TEST EQUIPMENT REQUIREMENTS FOR DEFIBRILLATOR SPECIFICATION CHECKS
REQUIREMENTS
OSCILLOSCOPE
Recommend:
HP 1741A or
HP 181A with 1801A
NECESSARY QUALIFICATIONS
Display:
Bandwidth:
Storage /Van* able Persistence
dc to 10 MHz
Vert. Deflection Range: 50 mV to 1 V/div
Storage Write Speed: 5 cm/jusec minimum
and 1820C plug-ins
ENERGY METER
Recommend:
Dempsey Model 429
STOPWATCH OR TIMER
Capable of 5 to 400 Joule damped sinusoidal
Waveform measurements with
±2% of full
scale accuracy. Load Resistance 50 ft
±1/2%
Capable of measuring 2 to 12 second events
with hand start/stop actuation to 1/4 sec.
accuracy
3-54
/^%
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-4
3.4.3.2
1.
Energy Accuracy.
Connect the equipment as shown in Figure 3-24,
DEFIBRILLATOR
OSCILLOSCOPE
CD
MODEL 429
DEMPSEY METER
Figure 3-24. Energy Accuracy Test Setup.
2.
Set the oscilloscope as follows:
Channel Selector
-
Sweep Mode to
- Single
Trigger to
Trigger Slope
Time/Division
Channel A
-
INT
-
+
- 1 ms/div
-0.5 volt/division or as
appropriate
- charging
Vertical Sensitivity
Press Trigger Reset While
3. Set the ENERGY SELECT control to each of the positions indicated in the table
below, press the CHARGE button and allow the unit to charge.
The CHARGE DONE LED
will light at the end of each charge cycle. Firmly press the paddles to the energy
meter and press both DISCHARGE buttons simultaneously.
Record the energy level
measured.
4. If the unit is equipped with an Annotating Recorder (78670A), refer to the
printed information for conformance to the delivered energy waveform information.
5. Record the peak voltage amplitudes of the damped sinusoidal waveform for later
calculation of Current Amplitudes (see section 3.4.3.3., step 3).
NOTE: The 78670A and 78671A should be operated on battery only when performing
this test.
If the power base is used, multiple ground paths through power line
cords can produce some misleading waveforms.
Energy Select
Setting
5
10
20
30
50
D 2li vere d
Joules
Energy
Meter
4
70
4
100
150
200
300
360
5
10
+
20
+
4
30
50
±
4.5
±
7.5
+
Energy Select
Setting
Del
ivered Energy
J oules Meter
70
100
150
200
±
±
±
±
300 +
360 ±
10.5
15
22.5
30
45
54
3-55
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.4.3.3
/*%
Delivered Energy Waveform Information (Recorder Printout)
1. If the recorder printout was not taken at the same time as steps 3.4.3.2,
Energy Accuracy, repeat steps 3.4.3.2, noting delivered energy on the energy meter
and the recorder printout information.
2.
Compare
the delivered
energy as read
on the
energy meter
against delivered
energy printed on the recorder chart. The printed data should be within 15% or 5
Joules (whichever is greater) of the actual energy displayed on the energy meter.
3. The energy meter acts as a 1000:1 voltage divider and outputs this signal to
the oscilloscope. Using this voltage and the 50 ft impedance of the energy meter,
the peak current can be calculated thus:
I peak = Energy meter output voltage X1000
50
Calculate these current values and compare with the printed current values. The
printed data should be within 8% or 2 amps (whichever is greater) of the calculated
values.
4.
If the printed current values are not within specifications, it will be
necessary to first perform the defibrillator output energy calibration (Section
3.3.13), setting the energy output as close to the set energy (5% or less) as
possible; then perform the self test accuracy adjustment (Section 3.3.15).
5. Compare the calculated current peak at 360 Joules with the specification value.
It should be 57 to 64 amps for 360 Joules.
3.4.3.4
1.
Self Testing Accuracy
Place the unit in the Service Mode as follows:
(a)
Turn the unit OFF.
Pull up on the BEEPER Volume
control knob
under
accessory door.
(b) Turn the unit ON and quickly push down on the BEEPER Volume control
(c) The unit should then display a test pattern on the CRT display.
2.
Make sure the paddles and the paddle contacts in the storage pockets are clean
and free of contaminants. This is to assure
paddle surface damage on discharge.
good electrical contact,
3.
Place the paddles firmly in their storage positions.
4.
Put the ENERGY SELECT switch in the 100 Joule position.
and avoid
Charge and discharge
the unit.
5. The LCD display should flash the test discharge energy of 90-110 Joules and if
the unit is equipped with an Annotating Recorder (78670A) it should print out the
test energy.
3-56
/m\
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-l
6. Place the ENERGY SELECT switch in the 360 Joule energy
discharge the unit. The LCD should display 324-396 Joules.
3.4.3.5
position.
Charge and
Defibrillator Capacitor Charge Time
1.
Install a fully charged battery of known good condition or connect the
defibrillator to a Model 78668A Power Base. The A-C line voltage to the Power Base
must be 110 to 120 volts.
2.
Use a stop watch or similar device to measure the time from pressing the CHARGE
button until the unit's CHARGE DONE light comes on.
3.
The table below notes the allowable charging times:
ALLOWABLE CHARGE TIME
BATTERY
POWER BASE
ENERGY
SETTING
360
4.
If the
allowable
charging time
8-10 sec
is
6-8 sec
exceeded, refer
to Section 3.3.14
for
adjustment procedure.
3.4.4
3.4.4.1
Synchronizer Section
Test Equipment.
Test equipment required to perform the
specification checks on the synchronizer is
listed in Table 3-7.
3-57
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
786 70A-1
TABLE 3-7
TEST EQUIPMENT REQUIREMENTS FOR SYNCHRONIZER SPECIFICATION CHECKS
NECESSARY QUALIFICATIONS
REQUIREMENT
Display:
OSCILLOSCOPE
Recommend:
HP 1741A or
HP 181A with 1801A
dc to 10 MHz
Vert. Deflection Range: 0.5V to 2 V/div
Storage Write Speed: 5 cm//a sec min.
Mode:
and 1820C plug-ins
2 channel, chopped
Output Level: 1 mV
Range: 60 and 120 BPM calibrated outputs
ECG GENERATOR/CALIBRATOR
Recommend:
Parke-Davis
Storage/Variable Persistence
Bandwidth:
3175
ENERGY METER
Capable of 5 to 400 Joule damped
Recommend:
sinuousoidal Waveform measurements with
Dempsey Model 429
± 2% of full scale accuracy.
Load Resistance 50 ohm
±1/2%
TEST CABLES/COMPONENTS
Recommend:
(2)
HP 11086A
BNC-BNC Cable
(1)
(1)
HP 8120-3164
HP 1251-7127
Signal Cable, ECG Output
Coaxial Adaptor, BNC to Phone Jack
(1
HP 14489B
ECG Cable
(1)
HP 14151A
Electrode Lead Set
3.4.4.2
1.
R-wave/Sync Pulse/Discharge Delay
Connect the test equipment as shown in Figure 3-25,
DEFIBRILLATOR
O
OSCILLOSCOPE
o
CHA
MODEL 429
DEMPSEY METER
11086A
14489B
PATIENT CABLE
_
14151A
ADAPTER
CD-
1251-7127
8120-3164
1 1086A
3175 ECG
GENERATOR/
CALIBRATOR
Figure 3-25. R Wave/Sync Pulse/Discharge Delay Test Setup.
3-58
CHB
J_JJ
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
2.
Provide power to the defibrillator and turn the ENERGY SELECT
control to the
monitor - ON position.
3. Turn the ECG generator simulator on (ECG SOURCE in LEADS I position).
4.
Set the oscilloscope controls as follows:
Vertical Sensitivity
Vertical Sensitivity
Chopped
Channel A
Channel B
5.
Display Mode
Sweep Mode
Sweep Trigger
Sweep Rate
Internal, Channel A
0.1 sec/div
Trigger Slope
+
Observe the
0.5 V/div
2 V/div
Normal
ECG output signal.
Adjust the
ECG Size Control for about
1 V on
the R-wave.
R
VERT.5V/DIV
T
P
11 11
TTlT 1MM
1 1 U -11 1 1
\
.Ljll-ll
1 M II
MM' JIM
MM.
Mil
JIM
Mil
1111
SWEEP .1SEC/DIV
!
Figure 3-26. ECG Output Waveform
6.
Reset the oscilloscope controls:
Channel A
Vertical Sensitivity
1 V/div
20 ms/div
Sweep Rate
7. Adjust the trigger sensitivity so that the sweep trigger does not trigger on
the P-wave but triggers on the positive slope of the R-wave as shown in Figure
3-27.
>
VERT=1V/DIV
/ii \.
I>V
11II
MM" J 1II
MM
III!
MM
MM
II11
IIII
SWEEP = 20mS/D IV
Figure 3-27. R Wave.
3-59
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670AJ78671A
78670A-l
8.
Press the SYNC/DEFIB switch to the
SYNC position and release.
The Sync/Marker
pulse should appear within 20 ms of where the peak of the R-wave had been
displayed. The Sync pulse obscures all but the first rise of the R-wave display as
shown in Figure 3-28.
RISE OF RWAVE-^
ill i i
TT-™ nu 11
•
111
1111
t H t "M 11
1111* "1111
II11
MM
Mil
MM
MM
MM
IIII
SYNC PULSE ^
Figure 3-28. Sync Pulse Superimposed on R Wave.
9. Push the SYNC/DEFIB switch over to the DEFIB position and release. Verify that
the Sync pulses are no longer present. Push the switch back to SYNC position.
10. Turn the ECG generator 0FF-0N-0FF quickly and verify that a single R-wave will
result in a Sync pulse. Set the ECG generator to VARIABLE BPM and slowly adjust
the rate control to both limits and verify that Sync pulses are available at all
beat rates.
11. Set the oscilloscope to SINGLE SWEEP. Slow the ECG generator to the slowest
rate. Set the defibrillator ENERGY SELECT to 360 Joules and press the CHARGE
button.
(a) After the CHARGE DONE indicator comes on, press the oscilloscope SWEEP
RESET button, press the paddles firmly against the energy meter contacts and press
the DISCHARGE buttons.
This will
short between Sync pulses.
probably require
assistance since the time is
Alternatively, leave the ECG generator OFF
until the
oscilloscope sweep is reset, the defibrilator paddles in contact with the energy
meter, and DISCHARGE buttons pressed; then turn ON the ECG generator.
(b) The
defibrillator discharge must
occur within 30
ms of the
pulse as shown in Figure 3-29.
DISCHARGE PULSE
FROM DEMPSEY
VERT = 2V/DIV
ft
4+H
-+H ff+4 ff++ m+ HH
-r
SYNC PULSE
VERT =1 V/DIV
SWEEP = 20mS/D IV
Figure 3-29. R Wave/Sync Pulse/Discharge Pulse Relationship.
3-60
Sync Marker
SECTION III CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
3.4.5
PADDLE CONTACT INDICATOR
3.4.5.1
Test
Test Equipment
equipment required to perform specification checks on the paddle contact
indicator is listed in Table 3-8.
TEST EQUIPMENT REQUIRED FOR PADDLE CONTACT INDICATOR
Requirement
Necessary Qualifications
61.1 ohm, 1%
250.0 ohm, 1%
Resistor
Resistor
3.4.5.2
1.
Turn
Paddle Contact Indicator Test
the instrument
ON to
MONITOR and
remove the
pockets. The first light bar (closest to the handle) on
light and blink on and off.
r2.
Connect
a 61.1 ohm resistor
between paddle
paddles from
the storage
the PCI indicator should
electrodes.
All
the light
bars
should be lit.
3.
Connect
a250.0ohm resistor between
paddle electrodes.
Only two
light bars
should be lit.
jf^v
3-61
SECTION III - CHECKS AND ADJUSTMENTS
Models 78670A/78671A
78670A-1
NOTES
3-62
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
PRELIMINARY INSTRUCTIONS
This
section
contains general
Defibrillator/Monitor.
procedures,
circuit
service
Included
information
in this
board removal
for
the 78670A and
section are mechanical
procedures
and
general service
78671A
disassembly
and
circuit
information.
Disassembly Precautions
For
your
own
safety,
observe the
following
precautions
before
starting
the
disassembly procedures.
WARNING - HIGH VOLTAGE
THIS INSTRUMENT STORES
HIGH VOLTAGE
HIGH VOLTAGE AND ENERGY.
AND/OR EXPLOSION HAZARDS.
DEFECTIVE
ALWAYS OBSERVE THE
COMPONENTS MAY PRESENT
FOLLOWING PRECAUTIONS
WHEN SERVICING THIS UNIT.
1.
Wear Safety glasses.
2. Ensure that energy storage capacitor is
zero and charged indicator is OFF.
3.
Remove the battery.
4.
Before servicing
discharged by observing that LCD reads
energy storage capacitor, see capacitor discharge procedure,
section 4.2.4.2
CAUTION
READ THE FOLLOWING PRECAUTIONS THOROUGHLY BEFORE PERFORMING ANY OF THE DISASSEMBLY
PROCEDURES. SERIOUS DAMAGE TO THE INSTRUMENT CAN RESULT IF THE PRECAUTIONS ARE NOT
STRICTLY FOLLOWED.
1. The CMOS logic family of integrated circuits can be damaged by an uncontrolled
static discharge. Before handling any of the circuit boards, firmly grasp the
instrument ground to eliminate any static charge difference between yourself and
the instrument.
2.
The analog ECG board (A3) has a floating ground section which is isolated from
the remainder of the
board.
Never handle this section of the
board - oils, dirt,
dust, etc., deposited on this section can cause leakage paths which can degrade ECG
circuit isolation and performance.
3. The plastic front panel
on these instruments scratches easily.
Avoid rough
handling of the panel.
4. Handle all circuit boards by the edges; CMOS circuits operate with currents in
the microampere range and leakage paths caused by skin oils, dirt, dust, etc., can
cause inaccurate circuit performance.
4-0
SECTION IV • MA INTENA NCE
Models 78670A/78671A
786 70A-1
SECTION IV
MAINTENANCE
4.1
MECHANICAL DISASSEMBLY
In order to gain
necessary to
access to the internal components, for service
open the instrument
case.
The case
or repairs, it is
consists of two
sections.
The
recorder, CRT and all circuit boards except the power supplies are located in the
upper section. The low voltage and defibrillator capacitor charging supplies, all
defibrillator high voltage circuits and components, and the battery are located in
the lower section.
4.1.1
Tools Required
- Medium posidrive screwdriver
- 1/4" nutdriver
4.1.2
r
Procedure
1.
Remove the battery.
2.
Lay the instrument on its top, preferrably on a protective pad.
3.
Refer to Figure 4-1.
4.
Remove
the two screws indicated
by Number 1
and the six screws
indicated by
Number 2.
5. The two screws indicated by Number 3 are accessed through holes in the case
bottom, but are located in the battery compartment. After the screws are loose,
reach through the battery opening and remove the screws.
6.
Hold the instrument case together and carefully turn it over.
II
Figure 4-1.
4-1
SECTION IV- MAINTENANCE
Models 78670A/7867IA
7 86 70A-1
7. Lift the top section off, turn it upside down, and place it on the bench to the
right of the lower section. The upper and lower sections are connected by wiring.
See Figure 4-2.
8. A metal shield covers the circuit boards in the upper
shield (see Figure 4-3):
(a) Remove the four screws indicated by Number 1.
(b) Remove the two hex standoffs indicated by Number 2.
DO NOT remove the hex standoffs at the rear of the shield.
(c) Lift the shield out of the case.
Figure 4-2. (78670A)
4.2
MECHANICAL REASSEMBLY
4.2.1 .A
Procedure
1.
Replace all previously removed components.
2.
Verify system operation.
4-2
section.
To remove the
SECTION IV • MA 1NTENA NCE
Models 78670Af78671A
786 70A-1
r
Figure 4-3. (78670A)
3.
Reinstall metal shield and mounting screws.
4.
Visually check that all wiring is properly placed and that none passes over any
mounting bosses.
5.
Close upper case over lower case - use caution that intercable lays properly -
especially at the left rear corner.
6.
Make
sure all
tabs that
project down
from the
upper case
engage correctly
around perimeter.
7.
Check engagement of cable housings at openings.
8.
Turn unit over onto its top while holding together and reinstall the screws.
9.
Reinstall battery.
4-3
SECTION IV - MAINTENANCE
Models 78670A/78671A
786 70A-1
4.2.1
4.2.1.1
Replacing the Low Voltage Power Supply Board
Procedure
1.
Remove the battery.
2.
Open the case as described in section 4.1.
3. Remove the five hex nuts
Figure 4-4.
(A) that secure
the L.V.
power supply
Figure 4-4. (78671A)
4.
Lift the board free and disconnect P23.
5.
Remove the H.V.
6.
Replace board and assemble in reverse order.
7.
Reassemble per section 4.2.
4-4
cable from the CRT.
See Figure 4-5.
See Figure 4-5.
board.
See
SECTION IV- MAINTENANCE
Models 78670A/786 71A
78670A-1
2.2.2
Paddle/Cable Assembly Replacement
(78671A and 78670A/A03) with non-interchangeable paddles.
These assemblies
may be
replaced individually.
The
procedure for
replacing the
cable within the housing is identical for both sides.
Both cable housings are
secured with double-sided adhesive foam tape, but the left side housing has an
additional mounting clamp. When the cable housings are removed from the case,
considerable pressure may have to be applied.
The foam tape may split, leaving an
adhesive surface stuck to the case and the cable housing. THIS MUST BE COMPLETELY
REMOVED BEFORE APPLYING NEW TAPE. The tape adhesive has very high tack and does
not come off easily by mechanical means. Certain solvents are useful but caution
must be exercised in selecting one that does not attack the base material. The
instrument case is polycarbonate, so acetone, MEK and similar solvents must NOT be
used. Isopropyl alcohol does not attack the plastic and will loosen the adhesive
if kept saturated for 2-3 minutes. If in doubt about the solvent, moisten a small
area inside the case with the solvent. Rub the area with your finger. If the spot
feels sticky, don't use it.
4.2.2.1
Tools/Parts Required
Medium size posidrive screwdriver
Long nose pliers
Solvent such as isopropyl alcohol
5/16" nut driver
Adhesive foam tape (PN 0460-1242)
4.2.2.2
1.
Procedure
Open the case as outlined in section 4.1.
NOTE: It
is possible to replace
cables without removing the
cable housings,
but it is not an easy job.
2. See Figure 4-4. At the rear of each cable housing is a 4 pin connector, P15
and P16, and part way along the side is a high voltage connector, P31 and P32.
Disconnect the cables for the side you wish
H.V.
to replace.
Unscrew the ring from the
connector body and pull apart.
3a. Apex side cable housing removal: See Figure 4-4.
Remove the five hex nuts
that secure the low voltage power supply board. Turn the board over and disconnect
the cable from the board (P23) (see Figure 4-5)
3b. Sternum side cable housing removal: Disconnect P16 near the rear of the cable
housing (see Figure 4-4). Remove the two screws (A) (see Figure 4-6), that secure
the cable housing clamp.
4.
Grasp the front end of the cable
housing and apply upward
pressure until the
housing comes free from the case.
4-5
SECTION IV - MAINTENANCE
Models 78670A/78671A
786 70A-1
5. See Figure 4-7. Unscrew the ring nut from the strain relief at the rear of the
housing and slide it over the connectors. The 4 pin connector is a tight fit but
it will clear.
Pull the cable from the housing.
Figure 4-5.
Figure 4-6.
4-6
SECTION IV- MAINTENANCE
Models 786 70A/786 71A
786 70A-1
^3
=0
PW\ i
CABLE
HOUSING
CLAMP
RING NUT
CABLE HOUSING
HIGH VOLTAGE
CONNECTOR
P32
Figure 4-7.
6.
When installing the new cable, be sure
to run the cable through the opening in
the top half of the case before inserting into the housing.
7. See Figure 4-8. Place the connector end of the cable into the large end of the
housing. The square flange on the strain relief will usually align itself, but a
second try may be necessary.
Figure 4-8.
4-7
SECTION IV • MAINTENANCE
Models 78670A\78671A
78670A-1
8. The cable is a snug fit so it must be pushed through the housing. Push the
cable until the H.V. connector contacts the rear of the housing. Use the long
nose pliers to get the connectors through the hole (see Figure 4-9).
Figure 4-9.
9.
Continue to push the cable until the threaded part on the strain relief extends
through the hole.
Tighten the ring nut on
the strain relief finger tight.
DO NOT
USE PLIERS.
10. Be certain the plastic surfaces are clean before applying the
tape. Place the tape on the bottom of the cable housing.
adhesive foam
11. The cable housing must be in the correct position before pressure is applied.
Place the housing against the side of the case with the open end contacting the
front of the case.
12.
Press
the cable
housing firmly
against the bottom of the
case to
set the
adhesive.
13.
Connect the cables, replace any other parts and test the paddle for proper
operation of the switches, indicator and delivered energy before closing case.
4.2.3
Replacing the Defibrillator H.V. Board
NOTE: A posidrive screw-holding screwdriver, or other screw holding device, is
helpful when replacing the screws that hold this circuit board.
In order to remove this circuit board, several other parts must be removed.
4.2.3.1
1.
4-8
Procedure
Remove the battery.
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
2.
Open the case as outlined in section 4.1.
3.
Unplug the paddle
and ECG output connectors (see Figure 4-4, Pll,
P15, and
P16).
4.
On the 78671A and 78670A, option A03, the sternum cable
in-line high voltage
connector, P32, must be disconnected and the sternum cable
Unscrew the collar and pull the connector apart (Figure 4-4).
5.
Remove
the two
Lift the housing
housing removal.
screws (A, Figure
out and set it aside.
housing
4-6) that secure the cable
See Section 4.2.2.2 for
removed.
housing clamp.
details on cable
6. Remove the five hex nuts that secure the low voltage power supply board. Lift
the board out and lay it aside. It is not necessary to disconnect the cables (see
Figure 4-4).
7.
Remove the battery relay (All-Kl).
8.
Remove the five hex posts (see Figure 4-5).
9. Disconnect the four push-on lugs near the relay and
battery compartment, near the center of the board.
^N
10. Disconnect P19, the P40 and P41, H.V. output leads
assembly (See Figure 4-5). Disconnect P21 and Pll.
11.
Remove the four screws (B) that secure the board.
4.2.4
4.2.4.1
the two wires
from the H.V.
from the
rectifier
Lift the board out.
Replacing H.V. Capacitor
Tools Required
— Medium posidrive screwdriver
— Long nose pliers with strong jaws
— Safety glasses
These capacitors are supplied with quick connect lugs.
4.2.4.2
Procedure
(Before removing the screws, stuff tissue paper in the hex shaped holes in the case
bottom. Place tape over the holes to hold the paper in place. This will keep the
hex nuts from falling out of the case.)
WARNING
JPN
Before performing service on this component, the capacitor terminals
should be shorted to prevent electrical shock. It is advisable to leave
a jumper cable on the terminals since this capacitor is capable of
recovering a charge.
4-9
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
1. Open the instrument case as outlined in section 4.1.
2.
See Figure 4-6.
/^
Remove the two capacitor clamp screws
(E).
Lift off H.V.
terminal cover.
3.
Before removing any
wires from the capacitor, draw a diagram to ensure proper
connection when the new capacitor is installed.
4.
After replacing the capacitor, test the unit before reassembling the case.
After reassembling the unit, remove the paper from the holes.
4.2.5
Safety Relay Replacement
NOTE:
There
are two
different
styles
of
relay
available, but
they
are
interchangeable and the procedure is the same for either type.
4.2.5.1
Tools Required
-Medium size posidrive screwdriver
- Soldering iron
-Safety glasses
4.2.5.2
1.
2.
Procedure: Before removing the screws, stuff tissue paper in the hex shaped holes in the case
bottom. Place tape over the holes to hold the paper in place. This will keep the hex nuts
from falling out of the case.
Open the case as outline in section 4.1.
Remove two
capacitor
clamp screws
(E)
,^%
(Figure
4-6) and
lift
it off
the
capacitor cover.
WARNING
Short out the capacitor leads and connect a JUMPER wire across
the capacitor
terminals to
prevent the
possibility of
electrical
shock.
3. Remove the two screws (A) and cable housing clamp. Remove the two inductor
cover screws (B), and lift off the cover. This exposes the safety resistor.
4.
At this point, draw a diagram to ensure everything gets connected properly when
the new part is installed.
Clip ty-wraps when necessary.
5. Unsolder the snubber wire from the safety resistor Al-Rl.
snubber wire from the H.V. capacitor.
Disconnect the other
6.
Unsolder the orange and yellow wire from the safety relay coil terminals.
7.
Remove the two screws (C) that secure the H.V.
snubber.
Remove the two safety
relay screws (D).
8.
Remove the safety relay wire from the lower H.V.
capacitor terminal.
Lift the
relay out.
9.
Put the new relay in place and route the wires from the H.V.
the screws in the snubber.
4-10
snubber.
Replace
SECTION IV - MAINTENANCE
Models 78670A / 78671A
786 70A-1
10.
Connect the wires.
11.
Test for proper operation before closing case.
12.
Install ty-wraps as required.
After reassembling the unit, remove the paper from the holes.
4.2.6
Patient Relay Replacement
4.2.6.1
Tools Required
— Posidrive screwdriver
Safety glasses
-Soldering iron
Diagonal pliers
—Small Ty-wraps
WARNING
Patient relay is a pressurized
unit and poses POSSIBLE
explosion hazard.
To prevent possible eye damage, safety
glasses should always be worn while performing this service.
4.2.6.2
Procedure: Before removing the screws, stuff tissue paper in the hex shaped holes in the case
bottom. Place tape over the holes to hold the paper in place. This will keep the hex nuts
from falling out of the case.
1.
Open the defibrillator case as outlined in section 4.1.
2.
Remove the metal
3.
Disconnect the paddle ECG leads from the ECG Analog Board (J28).
DEFIB
CONTROL
circuit board shield.
RECORDER C]_QCK/
A
'g*TAL ANAL0G
TARTRATE
Figure 4-10.
4-11
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
4.
Remove
the screws
78671A in which
housing clamp.
securing the inductor cover.
the two screws labelled
Figure
4-6 shows
(A) also fasten the
Remove these screws labelled (A)
the Model
sternum paddle cable
and (B) and lift off the inductor
cover.
5. Remove the capacitor clamp screws ((E) Figure 4-6) and
cover. Short the capacitor as described in Section 4.2.
lift off the capacitor
Draw a diagram of the
relay wires to aid reassembly.
6.
Refer
to 4-6.
Unsolder the
red and brown
wires from the patient
relay coil
terminals.
7. Cut the shrink tubing from the terminal on the inductor where the patient relay
high voltage lead is attached and unsolder the lead.
8. Disconnect the other
(quick disconnect lug).
patient relay high voltage lead from
the H.V.
capacitor
9a.
Units with non-interchangeable paddles (Model 78671A and 78670A/opt A03):
Disconnect the HV leads to the paddles at the connectors P31 and P32. (Figure
4-4).
9b. Units with interchangeable paddles: Use a pin extractor, HP P/N 8710-0614 (AMP
305-183) to remove the HV leads from the paddles connector PI, Pins 1 and 2.
(Figure 4-2).
Note: These wires are not interchangeable.
Be sure to install the replacement
relay with identical connections.
10.
Remove
the two screws
(F) that secure the
patient relay bracket.
Lift the
relay out.
11.
Install the new
relay.
Make sure no wires are wedged
between the relay body
and the lower case.
12.
Reconnect the wires.
terminal.
cables.
Use
Use shrink tubing
ty-wraps to
secure cable
of appropriate size on the inductor
bundles when
necessary.
13.
Test the defibrillator before closing case.
14.
After reassembling the unit, remove the paper from the holes.
4.2.7
Reconnect
all
Replace the shields.
Circuit Board Replacement
NOTE: All circuit boards are plug-in, except the two power supply boards which
are located in the bottom half of the case.
Only two boards in the top section of
the case need special attention, the others will present no problems.
4.2.8
1.
Recorder Board Assembly Replacement
Refer
to
Figure
defibrillator control
4-12
4-10.
board.
Unplug
the
flex
circuit
(P18)
and
remove
the
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
2.
A flat ribbon
cable, from
the recorder
printhead, plugs
into a small edge
connector on the recorder board (J30).
3.
Carefully remove
the recorder
board assembly
and
pull the
cable from the
connector, (J30).
4.
When replacing the hoard, connect the flat cable before plugging in the board.
The single, wide conductor in the ribbon cable goes toward the rear of the case.
4.2.9
1.
ECG Analog Board Replacement
There are
two cables
which attach
to this
board.
Unplug
the paddles
ECG
connector (P28).
2. Lift the FCG Analog Board up slightly to provide clearance and
contact cable connector (P42) coming from the switchboard and place
unplug the 15
it out of the
way.
3. Disconnect the flex
place it out of the way.
circuit (P18)
from the
Defibrillator Control
Board and
4.
Pull the ECG board up and out of the unit.
5.
When replacing the ECG board, ensure that the plastic cover halves are in place
over the metal shield section of the board.
i
4.2.10
1.
Switchboard Replacement
Remove the
ECG Analog Board as
described in 4.2.9.
Disconnect
the ECG input
connector, J26, from the switchboard.
2.
Remove the memory and deflection boards, Figure 4-10.
3.
Remove the ECG source knob (Refer to 4-2-16).
4. Use a 5/16 inch nutdriver to remove the nut from the switch mounting bushing.
Remove the screw from the right angle mounting bracket on the switchboard.
5. Pull the switchboard back into a position where the connector attached to the
LED's can be unplugged. This is a locking type connector and the locking side must
be pried out while exerting a pulling force.
6.
Install replacement in reverse order.
4.2.11
4.2.11.1
CRT Replacement
Tools Required
— Medium size posidrive screwdriver
—3/32" hex key
— Small flatblade screwdriver
NOTE: This procedure requires removal of the plastic overlay panel. This part
scratches easily, so care should be exercised during the following operations.
Remove the knobs as described in section 4.2.14.
4-13
SECTION IV • MAINTENANCE
Models 78670A/78671A
786 70A-1
It is
possible to
knobs.
remove the plastic
overlay panel without
removing all
of the
However, some manipulation of the panel is necessary.
WARNING
During the following procedure, HANDLE THE CRT WITH CAUTION. Wear protective safety
glasses. The cathode ray tube contains high vacuum and breakage can result in flying glass. Do not
strike or scratch the tube or subject it to more than moderate pressure during handling. Always
handle the tube by the main body, never by the neck alone.
4.2.12
Front Panel Removal
4.2.12.1
Tools Required
-
4.2.12.2
Small
flat blade screwdriver
Procedure
1. The front panel is secured by three plastic tabs spaced across the top of the
panel.
Insert the flat blade screwdriver between the tab and the panel, and
carefully pry the panel loose (see Figure 4-11 and 4-12).
Figure 4-12.
2.
Remove the battery.
3.
Open the case as outlined in section 4.1.
4.
Remove the metal circuit board shield.
5.
Disconnect the H.V.
the rear of the CRT.
4-14
lead from the side
of the CRT.
Unplug the connector from
~
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
6.
Loosen, but do not remove the yoke
clamp screw (see Figure 4-15).
Remove four
screws (two above and two below) from the face of the CRT (see Figure 4-13).
Figure 4-14.
Figure 4-13.
4
Figure 4-15.
7.
Hold the yoke with
the front panel.
one hand and slide the CRT out of
8.
Slide the new CRT in place.
9.
Slide the yoke as
clamp screw.
the yoke and out through
It is not necessary to remove the CRT shield.
Install the four screws at the face of the tube.
far toward the front of the CRT as
it will go.
Tighten the
DO NOT OVERTIGHTEN.
10.
Connect the high voltage lead and plug the connector to the rear of the CRT.
11.
Plug
in the
battery and turn
the monitor
on to be
sure the
tube operates
properly.
12.
Install the
front panel.
Place the edge
of the panel under
the bottom tabs
and press the top into place under each top tab.
13.
Set the minimum and maximum intensity adjustments as described in section 3.
4-15
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
14.
Check to see that the trace on the CRT lines up properly with the marks on the
panel.
If it does
not, loosen the yoke clamp screw and rotate the yoke until
proper alignment is achieved.
15.
Tighten the screw.
Center the trace by moving the trace centering levers on the yoke (see Figure
4-15).
Refer to section 3.
16.
Assemble the case per section 4.2.
17.
Install and align any knobs that were removed.
4.2.13
Replace the knob caps.
Fuse Replacement
There are
three fuses used
in this instrument.
One of
these is located
on the
defibrillator H.V. supply board (All) (see Figure 4-4). The two remaining fuses
are located on the interconnect circuit board (A2), which is located on the inside
top of the case (see Figure 4-15). It will be necessary to remove some circuit
boards to gain access to the fuses.
4.2.13.1
Procedure
1.
Open the case as described in section 4.1.
2.
Defibrillator
H.V.
supply fuse, All-Fl,
15A P/N 2110-0048 (see
Figure 4-4).
Remove relay Kl for easier access to fuse.
3.
Fuses on the interconnecting board A2-F1 and A2-F2, 3 amp P/N 2110-0003.
Remove the shield as outlined in section 4.1.2 (see Figure 4-3 and 4-10).
Fl: Remove the deflection board and the memory board.
F2: Remove the ECG digital and heart rate boards.
4.2.14
Knob Removal
4.2.14.1
Tools Required
- 3/32" hex key
4.2.15
ECG Size, Recorder, Alarm and ECG Source Knobs
4.2.15.1
1.
Insert
Procedure
your thumbnail
or a small
screwdriver into the
recessed area
at the
front of the knob and pry off the cap.
2. The knobs are secured to the control shafts by collets. Insert the hex key
through the front of the knob. Hold the knob to prevent rotation, and use the hex
key to loosen the collet by turning one full turn counterclockwise (see Fiqure
4-16).
4-16
SECTION IV - MA INTENA NCE
Models 78670A/78671A
786 70A-1
•
( I) ON
(Oi o n ♦
ENERGY SELECT
o
;ync
~1
Figure 4-16.
Figure 4-17.
tSt AI 100 JOIJlf 9
>
1
(I) ON
(Oi oi f
•
ENERGY SELECT
o
SVNC
'
1
Figure 4-18.
3. Pull the knob from the shaft.
If the knob hangs up on the shaft, it may be
necessary to insert the hex key back into the end of the knob and tap it very
gently to force the collet to release.
4.2.16
4.2.16.1
Knob Replacement
Procedure
1. There are no flats on the switch shafts; so when replacing the knob, it must be
properly aligned as the collet is tightened.
2.
Tighten the ECG Size, Recorder and Alarm knobs to 4 in/lb (this may be
approximated by tightening the collet until snug and then turning it an extra
turn). Be sure to hold the knob to avoid breaking the stops in the switch.
4.2.17
Energy Selection Knob
1. The pointer is an insert and is removed by prying up at the tail-end with your
thumbnail or a small screwdriver (see Figure 4-17).
2.
The knob is removed and reinstalled
as described in section 4.2.14 and 4.2.15,
except to tighten to 10 in/lb or 1/2 extra turn after snug (see Figure 4-18).
Test
to be sure the knob does not slip on the shaft.
4-17
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-2
4.2.18
Recorder Replacement
4.2.18.1
Tools Required:
-Medium posidrive screwdriver
- 3/32" hex key
-5/16" nut driver
4.2.18.2
Procedure
1. It is necessary
Pry off the caps on
collets. To loosen
the collet nut one
2.
3.
to loosen the two controls located directly below the recorder.
the front of the knobs. The knobs are secured to the shafts by
the collets insert hex key through the front of the knob. Turn
full turn counterclockwise, then pull the knob from the shaft
Open the instrument case as outlined in section 4.1.
See Figure
4-10.
defibrillator control
4.
Unplug
the flex
circuit
connector, P18,
and remove
the
board.
Carefully lift out the recorder board assembly and unplug the recorder
5.
Remove the recorder control board assembly.
6.
Remove the memory board, the ECG digital board and the heart rate board.
7. Unplug
4.2.9).
8.
10.
from ECG
analog board
and remove
the board
(see section
Use the 5/16" nutdriver to loosen the two controls directly below the recorder
housing.
9.
the cables
/^
j
printhead cable from J30.
It is not necessary to remove the nuts from the controls.
Unplug the recorder cable from J10 (see Figure 4-15).
See Figure 4-19.
Remove the five screws (A), that secure the recorder housing
(two in back and 3 in front). DO NOT
HOUSING. Lift the recorder assembly
REMOVE THE TWO SCREWS NEAR THE CENTER OF THE
from the instrument. Figure 4-19 is shown
without wiring for clarity.
11. The recorder is secured to the housing by four screws (see Figure 4-20). Lay
the recorder housing on a flat surface with the screws up.
Be careful not to
damage the QRS Beeper speaker which is on the opposite side of the housing.
12.
Remove the four screws
and carefully pull the recorder out of the housing.
The
speaker wires
allow
attached.
will not
Unplug the
point, the stylus
it to
and printhead are accessible.
the recorder mounted in the instrument.
4-18
be
cable from the recorder
completely removed
mounted circuit
with the
board.
The stylus can be
At
cable
this
replaced with
The procedure is described in section 7 of
ffS%
SECTION IV - MA INTENA NCE
Models 78670A/78671A
786 70A-1
Figure 4-19. (Shown without wiring for clarity).
Figure 4-20.
the Operator's Guide, so it will not be repeated here.
However, stylus replacement
is very easy with the recorder out of its housing (see Figure 4-21).
Instructions for
replacing the
recorder in the
instrument follows
the printhead
replacement procedure.
4-19
SECTION IV - MAINTENANCE
Models 78670A/7867IA
78670A-1
BALL END
HEX DRIVER
APPROX. .030"
A-STYLUS SCREWS
B - STYLUS PRESSURE ADJUST
C -
PRINTHEAD SCREWS
D -
PRINTHEAD ADJUST
Figure 4-21.
4.2.19
4.2.19.1
Printhead Replacement
Tools Required
Small phillips screwdriver, No. 0 point
4.2.19.2
1.
Procedure
Remove the
recorder
as
described in
section
4.2.17.
Place the
recorder
mechanism on a flat surface, stylus side up (see Figure 4-21).
2. Loosen the two printhead clamp screws and slide the printhead bar assembly out
from under the clamp. Pull the printhead and flat cable out of the housing.
3.
When
installing the
new printhead,
be sure to
.040") between the printhead bar and the edge
leave a
small gap
of the paper carrier.
(.030" to
Align the bar
so it is parallel to the edge of the recorder and tighten the clamp screws. There
is a groove in the printhead adjustment screw. A small projection from the
printhead bar assembly fits in this groove. Be sure the protection is engaged in
the groove when replacing the printhead.
4. The printhead may be adjusted before reassembly (See procedure below). Connect
the recorder and install the circuit boards. Load a roll of paper into the
recorder.
4-20
^
SECTION IV - MAINTENANCE
Models 78670A/78671A
786 70A-1
4.2.20
Printhead Adjustment
DOTS
DIRECTION OF
PAPER TRAVEL
CERAMIC PRINTHEAD
ROLLER
Figure 4-22. Detail of Print Head.
Only one adjustment is required to position the printhead.
The printhead
adjustment screw is accessed through the front of the recorder. After a printhead
is replaced, it is likely that no annotation will be printed. It may require
several turns of the adjustment screw to bring the printhead into the correct
position. Check to be sure the ribbon cable is properly inserted into connector
J30 on the recorder control board before attempting printhead adjustment.
4.2.20.1
1.
Procedure
The printhead
is a ceramic block which
is attached to the
stainless bar (see
Figure 4-22).
2. The printhead dots are in a row running across the printhead.
located approximately .060 from the front edge of the ceramic block.
The row is
The row of
dots must be centered above the roller for proper operation. The adjustment screw
moves the printhead to place the dots over the roller (see Figure 4-21).
3.
Turn the monitor on and press the 8 second run switch to obtain a printout.
4. Examine the printout with a 10 x magnifier. The density of the dots should be
uniform over the entire area of the dot. (Note: The dots are square). If the dots
are darker at the leading edge and lighter at the trailing edge, the printhead is
behind the roller.
printhead forward.
Turn
the adjustment
screw
counterclockwise
5. If the dots are lighter at the leading edge and darker at
the printhead is in front of the roller. Turn the adjustment
move the printhead back.
to
move
the
the trailing edge,
screw clockwise to
NOTE: When making adjustments, turn the screw no more than 1/2 turn at a time.
After each adjustment, run the recorder and examine the dots with a magnifier.
6. When you are satisfied that the
recorder in its housing.
printhead is correctly positioned, install the
4-27
SECTION IV - MAINTENANCE
Models 786 70A/786 71A
78670A-1
4.2.21
4.2.21.1
Recorder Assembly Installation
Procedure
1. Place the recorder in the 78670A or 78671A upper case and position the recorder
cables where they will be out of the way.
2.
Lift the
two recorder controls and
slide the recorder housing
into position.
Replace the five screws that secure the housing.
3.
Tighten the control nuts and replace the knobs (see section 4.2.16).
4.
Plug in the ECG Analog board (A3) and plug in the cables.
5.
Plug in the recorder control/cable to A2-J10.
6. Plug in the digital ECG board and the Clock/Heart Rate board. Carefully plug
the printhead cable into J30 on the recorder board. (The wide conductor goes
toward the rear of the instrument case). Install the circuit board.
7.
Install the defibrillator control board and connect the flex circuit P18.
Plug
in the deflection and memory boards, if they were removed.
8.
Test the recorder before installing the circuit board shield.
4.2.22
QRS Beeper Speaker Replacement
(Order speaker P/N 9164-0133 and ring gasket 0905-0889)
1.
The speaker is mounted to the top of the recorder housing.
removed in order to gain access to the speaker.
BEEPER SPEAKER
9164-0133
RING GASKET
UNDER SPEAKER
09050889
PLASTIC RIVET
1400-1038
SPEAKER RETAINER
BRACKET
78660-07114
Figure 4-23. Top View of Recorder Housing.
4-22
The housing must be
Refer to section 4.2.18.
SECTION IV- MAINTENANCE
Models 78670A/78671A
78670A-1
2. Remove the recorder mechanism from the housing. Refer to Section 4.2.18.2,
paragraph 11 and 12.
Press out the two plastic rivets that secure the speaker
bracket.
These rivets must be pressed out from inside the recorder housing.
3.
The speaker is secured to the recorder housing by a ring of double-side
adhesive foam tape. When the old speaker is removed, the tape may separate leaving
a layer
4.
stuck to the
recorder housing.
The mounting surfaces must be free of
all tape residue and grease.
Wipe these
surfaces with isopropyl alcohol and allow to dry for a few minutes.
5. Peel the protective paper from one side of the adhesive foam ring.
DO NOT
TOUCH THE ADHESIVE SURFACE. Position it on the recorder housing. When the ring is
correctly positioned, apply gentle but firm pressure all the way around to set the
adhesive.
6.
Peel the
speaker.
protective backing from the other
side of the ring
and position the
Apply pressure to the speaker magnet and hold for about one minute to set
the adhesive.
Not too
much pressure or you may damage
the speaker
(see Figure
4-23).
7.
Solder the speaker wires.
rivets.
r
Install
Position the speaker bracket and install the plastic
the recorder in
the housing.
Proceed with the
installation as
outlined in section 4.2.21.
f
Figure 4-24.
4.2.23
"Paddles in Place" Reed Switch Replacement
(Reed switch 0490-0194, cover 78660-40034, adhesive gasket 78660-40035)
4-23
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
1. This switch is mounted under the apex paddle pocket. The switch is mounted
under a plastic cover which is secured
adhesive foam gasket (see Figure 4-24).
2.
Use a pocket
to the
paddle pocket
knife to pry the plastic cover from
by a
/j
double-side
the paddle pocket.
Unsolder
the wires from the reed switch.
3.
Solder the wires to the new switch.
4. In order to mount the replacement cover, the paddle pocket must be free of all
residue from the old adhesive foam gasket.
Remove with a pocket knife or
screwdriver and wash the surface with isopropyl alcohol.
5. Wash the mounting surface of the cover with alcohol. Peel the protective cover
from one side of the adhesive foam gasket. DO NOT TOUCH THE ADHESIVE SURFACE.
6. Place the reed switch in the cavity in the cover and place the adhesive surface
of the gasket on the plastic cover. Apply firm but gentle pressure to set the
adhesive. Be careful not to damage the reed switch.
7. Peel the protective cover from the other side of the gasket and place the cover
in position over the paddle pocket terminal. Press around the edges to set the
adhesive.
4.2.24
1.
ENERGY SELECTOR Switch Replacement
Remove the ENERGY SELECTOR Knob (see section 4.2.17).
2. This switch is mounted to the lower front panel
but is electrically connected
to the flex circuit (see Figure 4-24). Exercise caution when removing the switch
from the flex
step 4).
3.
Unsolder
circuit.
Unsolder the flex
the 2 heavy wires
circuit with the switch
from the power switch
^^
/^
in place (see
mounted on the rear
of the
ENERGY SELECTOR.
4.
The following procedure requires a small soldering iron with a fine point.
solder wick
or a solder sucker to loosen the
circuit.
DO NOT OVERHEAT THE FLEX CIRCUIT.
six solder terminals from
Use
the flex
5. After the solder has been removed from all six terminals, insert a scribe or a
fine blade screwdriver between the flex circuit and the switch body. Work across
the switch body so that the flex circuit is removed evenly all the way across.
6.
After the flex
circuit is removed from the switch, lay
on its side. Use a nut driver to loosen the switch.
IS INSTALLED ON THE SWITCH.
7.
Place the
hardware on the new
switch in the same
NOTE
4.2.25
1.
solder
THE ORDER THE HARDWARE
order as it was
switch. It will be necessary to move the switch around
engages in the hole in the housing. Tighten the nut.
8.
Place the flex circuit over the
Reconnect the wires to the power switch.
the upper case housing
until the
terminals and
solder
on the old
locating lug
in
place.
Other Components Mounted on the Flex Circuit
These include the SYNC and CHARGE DONE LED's, the SYNC/DEFIB switch and the LCD
(see Figure 4-25).
4-24
/^\
SECTION IV- MAINTENANCE
Models 78670A/78671A
786 70A-1
r
REED SWITCH
CONNECTOR
TERMINALS
MONITOR SWITCH
(POWER) S1B
Figure 4-25. Flex Circuit Assembly(A-16).
2.
Refer
to section 4.2.24 concerning
procedure for unsoldering
components from
the flex circuit.
3.
When replacing LED's, note polarity.
The longest LED wire is positive.
Always
install any panel mounted part before soldering to the flex circuit.
4.2.26
SYNC/DEFIB Switch Replacement
-Switch 3101-2398
- Energy switch decal
4.2.26.1
Tools Required
Soldering iron and solder sucker
5/16" nut driver
4.2.26.2
Procedure
1. The SNYC/DEFIB switch bezel is secured by the ENERGY SELECT switch decal. It
is possible to remove the switch bezel by lifting the lower end of the decal.
However, a spare decal is good insurance.
r
2.
After the bezel is removed, pull the plastic knob off the switch lever.
3.
Open the unit as outlined in section 4-1.
4-25
SECTION IV- MAINTENANCE
Models 78670A/78671A
78670A-1
4. See Figure 4-24. Use a solder sucker or solder wick to unsolder the switch.
Be careful not to
overheat the flex circuit.
The flex circuit
^
must be loose from
all three switch terminals before attempting to remove it from the switch.
5.
Turn the
top half of the
case on its side.
Remove the nut that
secures the
switch. Note the order in which the hardware is assembled on the switch.
be installed in the same order on the replacement switch.
It must
6. Install the new switch. After it is tightened, solder the flex circuit to the
switch. Do this quickly to prevent overheating of the flex circuit.
7.
8.
Test the switch for proper operation before reassembling the case.
Install the
switch
knob and
bezel.
If
the ENERGY
SELECT
decal must
be
replaced, exercise care in alignment around the ENERGY SELECTOR switch.
4.2.27
Flex Circuit Replacement (Refer to Figure 4-25)
1. The flex circuit assembly is supplied with all parts soldered in place. The
installation can be made easier if the SYNC/DEFIB switch is unsoldered from the
flex circuit and the old switch left in place.
2.
Refer to section
4.2.24 for removal of the ENERGY
SELECTOR switch and Section
4.2.28 on LCD removal, since both of the parts are soldered to the flex circuit.
/*%>
3.
The CHARGE DONE and SYNC LED's are each secured by one screw.
Unplug the reed
switch cable from the flex circuit.
4.2.28
Liquid Crystal Display Replacement
The LCD holder is soldered to the flex circuit. Figure 4-24 shows the flex circuit
as it appears when installed. Figure 4-25 is the flex circuit assembly.
No soldering is necessary to change the LCD but caution should be exercised when
working with the flex circuit since it can be damaged by careless handling.
4.2.28.1
Tools Required
-Medium size posidrive screwdriver
READ THIS ENTIRE SECTION BEFORE PROCEEDING
4.2.28.2
Procedure
1. Open the instrument as outlined in section 4-1 and remove the circuit board
shield. Unplug the flex circuit from the Defib Control board (P18).
Unplug the
two wire connector from the mother board that contains the power switch wires.
2.
Remove the two
screws that secure the internal test load
necessary to remove the wires.
opening (see Figure 4-26).
Lift the resistor and position
resistor.
It is not
it over the handle
3. Remove the two screws from the LCD clamp (Figure 4-26) and the single LCD
holder screw, located directly behind the ENERGY SELECTOR switch (Figure 4-27).
4-26
SECTION IV - MAINTENANCE
Models 78670AJ78671A
78670A-1
r
Figure 4-26.
LCD HOLDER
SCREW
LED CLAMP
SCREW UNDER
FLEX CIRCUIT
j*
Figure 4-27.
Figure 4-28.
4.
Just to the
left of the ENERGY SELECTOR switch is the
CHARGE DONE LED.
There
is a screw in front of the LED that must be removed. It will be necessary to bend
the flex circuit to allow passage of a screwdriver. Start at the forward edge and
bend the flex
circuit down.
00 NOT ATTEMPT
carefully pull the LED from the Front panel.
TO BEND IT UP.
Remove
the screw and
DO NOT pull the flex circuit.
4-27
SECTION IV - MAINTENANCE
Models 78670A/78671A
78670A-1
5. The LCD holder has a projection at the top edge which slides under a tab on the
back of the front panel. Without attempting to lift the flex circuit, slide the
LCD holder toward the
ENERGY SELECTOR switch, until the LCD holder
is off the tab
on the panel.
6.
Carefully fold the flex circuit back over the ENERGY SELECTOR switch to expose
the LCD holder (see Figure 4-28).
7. If trouble was experienced with the display and it has been determined that the
problem lies in the LCD, examine the LCD holder to be sure the contacts are
centered on the LCD. Gently push the LCD from side to side but not so far that the
end of the LCD goes beyond the end contact and allows the contact to drop.
8. When reinstalling the LCD holder, be certain the projection on
LCD holder is engaged with the tab on the panel.
4.2.29
LCD Replacement
4.2.29.1
1.
the top of the
Procedure
The LCD is mounted in a glass sandwich
sides.
These
with the contacts along the top on both
contacts are a thin film, and nearly
under the proper lighting conditions.
transparent, but can
be seen
Avoid touching the contact surface with the
fingers.
2.
Since the
glass sandwich
has an abrupt edge,
employed when installing an LCD in the holder.
a special
technique must
be
IF THIS IS NOT DONE, THE LCD HOLDER
CONTACTS WILL BE DAMAGED.
3. When replacing an LCD, one method is to use the new LCD to push the old one out
of the holder. As long as a gap is not allowed to form between the two LCD's, no
problem should be encountered.
4.
When installing an LCD in the holder when there is no display in place, use the
following procedure:
(a) Obtain two strips of hard plastic such as mylar.
about .005 inches thick, no wider than the
longer than the LCD.
These strips should be
LCD contact surface and an inch or more
(b) Slide a strip under each set of LCD holder spring contacts.
(c) Slide the LCD in under the plastic strips.
the LCD contacts and
the holder contacts.
The
strips should be between
When the LCD has
been inserted all the
way into the holder and centered between the contacts, pull the plastic strips out.
5. Before the new LCD is installed, it must be correctly oriented.
are toward the right side of the display when installed in the unit.
The three 8's
When the unit
is open and the flex circuit folded back over the ENERGY SELECTOR switch, the 8's
go toward your left.
6. Peel the protective plastic cover from the LCD if this has not been done.
Check the surface of the display for dirt or fingerprints before assembling the
unit.
4-28
Check the display for proper operation before closing the case.
/*%
'
SECTIONIV - MAINTENANCE
Models 78670A/78671A
78670A-l
4.2.30
LED Replacement, Front Panel
4.2.30.1
The
Procedure
ECG
Source
and
low
battery
indicator
LED's
can
be
replaced
without
disassembling the case.
1.
Remove the front panel as described in Section 4.2.12.
2.
Carefully
pull out
the LED assembly
far enough to
covering the soldered connection.
LED assembly.
Cut and
3.
replacement LED.
Observe
the polarity
of the
access the
remove the shrink tubing.
The wiring
shrink tubing
Unsolder the
color code
is as
follows:
INDICATOR
4.
Install the
POSITIVE (LONG) LEAD CONNECTION
ECG Paddles
Orange
ECG Leads
Yellow
Low Battery
Wht/Blu
new LED being
sure to
replace the
shrink
tubing (1/16
inch
0890-0732 is recommended).
4.3
RECHARGEABLE NICKEL CADMIUM BATTERY - Bl
Many nickel cadmium batteries are needlessly replaced each year because service
personnel did not understand their characteristics. Most storage batteries require
a certain amount of maintenance, and the nickel cadmium battery is no exception.
However, their maintenance requirements are quite different from an automobile
battery, for example.
4.3.1
General Description
The battery (Bl) used in the portable defibrillator is a 10-cell, 2.0 AH sealed
nickel cadmium type.
It is charged with a constant current source of 200 mA and
can sustain overcharging indefinitely at this rate. The internal construction and
chemistry of the battery is such that oxygen generated during overcharging rapidly
diffuses through the cell and recombines at the negative plate.
Consequently,
there is no excessive pressure build-up in the cells and the excess energy is
converted to heat; a fully-charged battery will be warm to the touch when kept on
overcharge. Since no detrimental effects occur because of overcharging, the unit
should be kept charging whenever practical.
4.3.2
Charge Retention
The nickel cadmium battery has a relatively high self discharge rate, when compared
to other types of batteries. Charge retention depends on the storage temperature
4-29
SECTION IV - MAINTENANCE
Models 78670A/7867IA
78670A-1
and
the age
and condition
of
the battery.
The
self discharge
rates for
new
batteries are listed below:
Self Discharge/Month
Temperature
4.3.3
0°C (32°F)
10%
20°C (68°F)
30%
40°C (104°F)
70%
Charging
The heat generated during normal overcharge however, necessitates that the battery
not be charged when the ambient temperature exceeds 45°C. The battery should not
be charged when the ambient temperature is below 5°C. Charging below this
temperature may cause build-up of excessive pressure, with a resultant venting of
the cells.
Venting will cause loss of electrolyte and gradual loss of battery
capacity.
4.3.4
Voltage Depression (Memory)
Nickel cadmium batteries that are left on continuous charge, for long periods of
time, suffer from a voltage depression pheomenon. The terminal voltage, under
load, will be about 1 volt less than that of a battery in good operating condition.
The apparent effect is reduced battery capacity, sometimes referred to as memory.
Under conditions of long continuous charge, the crystals of active material within
the plates of the cells, begin to increase in size. As the crystals grow larger,
the surface area of active material in contact with the electrolyte decreases. The
effect is an increase in internal resistance of the battery. This will be
exhibited as premature flashing of the low battery warning light.
4.3.5
What To Do About It
The effects of voltage depression can be eliminated by exercising the battery every
3 months. This can be accomplished by turning on the monitor for about 3 hours,
and allowing the battery to discharge.
An alternate method is to connect the
battery to a test load (HP 78620-60860). Connect a voltmeter to the test load and
monitor the discharge. Discharge the battery until the voltage falls below 10
volts. DO NOT ALLOW THE VOLTAGE TO FALL BELOW 9.0 VOLTS, or cell reversal may
occur. Use Model 78660-67300 adapter to connect the battery to the test load. The
test load will become quite warm during this procedure.
4.3.6
Cell Reversal
Cell reversal, due to deep discharge, can occur whenever the battery voltage drops
low enough (i.e., below 9 volts) to cause one of the cells to reach zero volts.
The current flowing through the battery pack will then tend to reverse-charge this
(weakest) cell. Reverse ch arging generates hydrogen and oxygen which will cause a
rise in internal pressure and possible subsequent venting if the pressure increases
sufficiently.
The cells have resealable vents, and only a small amount of
electrolyte escapes during venting. However, after 10 or more venting incidents,
the affected cell will begi n to lose capacity and reach reversal earlier.
To
minimize
manufacturing.
4-30
this
This
possibility,
cells are
ensures that the
closely
loss of the
matched
in
capacity
weakest cell will
during
be followed
/^k
SECTION IV-MA INTENA NCE
Models 78670A/78671A
786 70A-1
shortly by the collapse of the remaining cells. Therefore, when the weakest cell
is fully discharged, the remaining cells have so little capacity that current flow
is not enough to seriously reverse-charge the weakest cell. This matching of cell
capacity makes it imperative that individual cells never be replaced. In the event
of a weak battery, the entire battery pack must be replaced.
As a further
precaution, turn the unit off, or plug in whenever the trace starts to dim or has
disappeared.
4.3.7
Battery Replacement
As a battery ages, its capacity will be reduced. If the LOW BATTERY warning starts
flashing after only 2 hours of monitoring, and the voltage is not depressed due to
long term continuous overcharging, the battery is showing signs of weakening. A
fully charged battery should be capable of sustaining at least two hours of
monitoring before the trace dims. If the battery is incapable of meeting this
minimum, it should
be replaced.
However, test the battery
before replacing.
See
section 3.2.3.7.
4.3.8
Storage of Nickel Cadmium Batteries
Batteries that are stored for several months without recharging will occasionally
develoD a short circuit in one or two cells, which renders the battery useless.
If the batteries must be stored, they should be charqed about once a month if
stored at normal room temperature. The recharge interval may be extended to about
three months if the batteries are stored in a refrigerator. In this case, allow
the battery to warm up for several hours before charging.
After removal from storage, the battery should
once or twice to restore its capacity.
4.4
be deep discharged
and recharged
RECORDER STYLUS REPLACEMENT (1530-0359)
4.4.1
Tools Required
5/16" hex driver (8710-1196)
Stylus force gauge (8750-0345)
4.4.2
1.
Procedure
Remove the battery and place the instrument with the front panel facing up.
2. Refer to section 3.3.17.1 and the right hand illustration.
pressure adjust screw. Remove the two stylus mounting screws.
Loosen the stylus
Grasp the stylus
assembly and pull it from the recorder.
3.
Reverse the procedure to install the new stylus.
4.
Perform stylus pressure adjustment as outlined in Section 3.3.17.
4-31
SECTION IV- MAINTENANCE
Models 78670A/78671A
78670A-l
4-32
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
SECTION V
TROUBLESHOOTING
5.1
INTRODUCTION
This portion is divided into two sections.
major component level.
The first section is
board level and
The second section is component level troubleshooting by board or circuit.
5.2
BOARD LEVEL
SYMPTOM
REFER TO
SECTION
PAGE
System Dead
5.2.1
5-2
Defibrillator Problems
5.2.2
5-2
LCD Readout Problems
5.2.3
5-4
Error Messages on LCD
5.2.4
5-5
CRT Display Problems
5.2.5
5-5
Recorder Problems
5.2.6
5-7
LED Indicator Malfunction
5.2.7
5-9
ECG Signal Problems
5.2.8
5-10
Real Time Clock Problems
5.2.9
5-10
Control Problems
5.2.10
5-11
Service Mode Problems
5.2.11
5-11
Battery/Power Base Problems
5.2.12
5-12
Component Level Troubleshooting
5.3
5-13
5-1
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
/^k
5.2.1
System Problems
SYMPTOM
System Dead.
Battery voltage
normal or power base
operation.
SUSPECT AREA
Fuse A2-F1 and F2
CHECKS
Check fuses on
mother board (A2)
Battery relay, All-Kl
V Ref on defib H.V.
board (A-ll)
TP-5 to ground 5.4
volts +/-2% (see
section 3 for
calibration procedure)
Power switch/wiring
Power base
See section 7
Low voltage power
Troubleshoot low
supply (A12)
voltage power
supply board (A12)
Defibrillator charge
time may vary at same
energy setting.
Strange LCD and
Noise caused by HV arc
HV charger board, All.
Rectifier assembly A13.
Be sure contacts
recorder readout. Not
All-Tl
Look for H.V. arcing
during charge.
repeatable.
5.2.2
are seated.
/"^
Defibrillator H.V. Problems
SYMPTOM
Will not charge;
SUSPECT AREA
SW. BAT No. 2 fuse
LCD shows zeros
CHECKS
Check fuse A2-F2
mother board (A2)
Defib supply fuse
All-Fl on defib
charger board (All)
Defib control board (AlO)
Will not charge.
LCD blank
Defib charger board (All)
If +12 volts not
present on P17 Pin 11
when CHARGE switch
pressed.
ENERGY SELECTOR switch
binary coding
Place ENERGY SELECTOR
in MONITOR position.
CHARGE DONE LED should
flash when CHARGE
switch pressed and
released.
5-2
/*%
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-2
Will not discharge in
Patient relay drive
Voltage across patient
relay coil should go
from zero to approx
Defib control board
+12 volts at
(A-10)
discharge.
DEFIB mode.
Will not discharge in
Defib control board (A-10)
SYNC mode or will not
go into SYNC.
ECG digital board (A4)
SYNC switch or flex
circuit (A16)
Will not discharge
in
SYNC mode but SYNC
LED flashes
LCD shows approx 5-10
Defib control board (A-10)
Flex circuit (A-16)
Check through to
SYNC LED
LED
Defib control board (A-10)
Pull fuse All-Fl.
Check on P28 Pin 4.
Joules but unit
continues to charge
Safety relay drive
when set to 10J
Should rise to approx
+12 volts when
CHARGE switch is
pressed.
Safety relay, A1-K2
Pull fuse All-Fl.
REMOVE COVER FROM HV
DEFIB CAP (Al-Cl).
CAUTION:
(1) SHORT HV CAP TERMINALS BEFORE
CONTACT, TO BLEED CHARGE.
DISCONNECT OHMMETER
ACROSS HV CAP LEADS
(2) RECONNECT LEADS TO Tl BEFORE
NORMAL READING, lOKfl.
CHARGING DEFIBRILLATOR.
WHEN CHARGE SWITCH
CLOSED, SHOULD SHOW
CAPACITOR CHARGE THRU
OHMMETER FOR 5 SEC
P5 ERROR SIGNAL, THEN
10KHA5 SAFETY RELAY
RECONNECTS SAFETY LOAD,
Defib continues to
charge.
LCD shows
zero or low value.
Shorted H.V. capacitor
Al-Cl. (A loud bang
during charge usually
indicates a shorted cap).
Ohmmeter check as
above.
Shorted cap
indicates less than
lOKn.
Defib H.V. board (All)
or H.V. rectifier
Safety relay
Unit charges to safety
cutoff.
Test as noted above.
Defib control board (AlO)
LCD indication
may be zero or exceed
highest energy setting.
Defib H.V. board (All)
If P17 Pin F is
zero volts.
Charge time excessive.
Low battery
Substitute
5-3
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-2
/^I
Audible chirp when
charging.
Power base
Check V raw under
defib charger load.
Should be greater
than 10 volts.
section 7
Oscilloscope discharge
waveform from energy
meter is RC decay
instead of damped
See
Charge time calibration
(A11-R34)
See section 3 for
Shorted defib inductor
Replace
calibration procedure.
(Al-Ll)
sine wave.
Inaccurate, inconsistant
defib
Patient relay Al-Kl
output
Inspect for internal
discoloration or
very bright flash on
discharge.
WARNING:
WEAR EYE
PROTECTION. EXPLOSION
HAZARD.
Defib H.V. Board (All)
Very high peak current.
High delivered energy.
5.2.3
Shorted inductor A1,L1.
LCD Readout Problems
SYMPTOM
No 8's at turn-on on
SUSPECT AREA
CHECKS
Defib control board (AlO)
LCD
No LCD or recorder
Defib control board (AlO)
digits
Missing digit or
segment in LCD
Defib control board (AlO)
LCD holder
Attempt to adjust.
See section 4 on
LCD replacement.
LCD
Check for cracks
or improper position
in LCD holder.
LCD blurry
5-4
Defib control board (AlO)
/•^
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
£^\
Memory board (A5)
Flex circuit
Missing LCD digit but
Defib control board (AlO)
recorder message O.K.
5.2.4
ERROR Messages on LCD
(When there's an error mesage, the LCD's will flash the error number and energy
alternately).
SYMPTOM
SUSPECT AREA
PO error
Defib control board (AlO)
NOTE:
CHECKS
UIO bus (Port 0)
This error may not show up as PO error on
the LCD's because the bus has been effected.
PO error
Defib control board (AlO)
UIO pin 14 or 25
PI error
Defib control board (AlO)
U14
Power supply board (A12)
+5V
Defib H. V. board (All)
+5.4V ref
P2 error
Defib control board (AlO)
Ull A/D converter
P3 error. Cap
overcharged
Defib H.V. board (All)
P4 error
H.V. defib section
Leakage to ground
H.V. cap
Shorted H.V. cap
Patient relay
Arcing in relay
P5 error.
Can't
Vcap monitoring
circuit
Safety relay or drivers
charge
0*^
2.5V ref
Safety relay doesn't
open
Defib H.V. board (All)
PWM charging circuit
H.V. cap
Cap leaking charge
P6 error
Patient relay
Arcing in relay
P7 error. Unexpected
energy detected on cap
Safety relay
Stuck open
Defib control board (AlO)
Safety relay driver
Defib H.V. board (All)
Safety relay driver
5-5
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
??< error. Can't charge
Low battery
PO error
Defib control board (AlO)
R72 adjusted out of
range.
H.V. cap
5.2.5
Out of tolerance
CRT Display Problems
CHECKS
SUSPECT AREA
SYMPTOMS
Heart rate digits
missing or bad digits
Clock/Heart Rate boards (A7)
Deflection board (A6)
Memory board (A5)
Recorder board (A8)
Heart rate digits
flash.
Recorder board (A8)
Characters
printed on recorder
wider than normal.
Wrong heart rate
displayed and printed
ECG digital board (A4)
Recorder board (A8)
Vertical jitter on CRT
digits. Distortion on
L.V. power supply board
(A12)
Check -12 volt supply
L.V. power supply board
(A12)
Check + and -15 volt
Trace shrinks and moves
L.V. power supply board
to center of CRT. Edges
(A-12)
Check +5 volt supply.
(5.0 to 5.1 volts with
all boards in place).
recorder trace.
Modulation on trace
edge, trace shrinks,
CRT digits deformed
of trace fold inward.
Fuzzy, out-of-focus,
jittery trace. Modulation
up and down
NOTE:
If out, adjust A12-R14
See section 3.
If the 5 volt supply is out of regulation,
all other supplies may be out as well.
5-6
supplies
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
No vertical deflection
Deflection board (A6)
on ECG trace
Deflection yoke
Measure resistance.
See interconnect
schematic, Figure 6-2.
Asymetrical vertical
Deflection board (A6)
deflection.
Vertical crossover
distortion
ii
ii
No horizontal deflection
ii
ii
Asymetrical horizontal
ii
ii
ii
ii
ii
H
deflection
Beam does not turn off
(no retrace blanking)
Cannot control intensity
No brightness
CRT filament
Turn power OFF. If
dot appears on CRT,
CRT and anode H.V.
are O.K.
+200 volt supply
Measure at P3 Pin A
Anode high voltage
Remove CRT anode
connector and arc
to CRT shield.
WARNING: 5000 VOLTS
No CRT trace or digits
Brightness and trace
length varies. Spikes
on trace
No ECG signal on CRT
Memory board (A5)
(CRT digits and
recorder ECG O.K.)
ECG trace breaks up
5.2.6
Memory board (A5)
Recorder Problems
SYMPTOM
Recorder will not run
or will not shut off
SUSPECT AREA
CHECKS
Recorder control board (A8)
5-7
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-l
/^k
CHECKS
SUSPECT AREA
SYMPTOM
Recorder will not run
or will not shut off
Recorder control board (A8)
Recorder run switch/cable
recorder
Recorder will
not run,
Slight movement when
MARK switch pressed.
Recorder fully closed.
Recorder
Recorder board (A8)
No movement when 8
second run switch
pressed
Automatic recorder
Recorder control
run on defib charge,
does not operate.
(A8)
Defib control
board
board
(AlO)
No recorder ECG trace
heart rate and CRT
Pen heat adjust
digits normal
Recorder control board
See Section III
(A8)
Stylus
Replace.
See Section
IV of this manual
Stylus moves with
Recorder control board
recorder off
(A8)
Stylus does not move
Recorder control board
with recorder on
(A8)
Memory board (A5)
Stylus pinned or large
Recorder control board
stylus offset
(A8)
Memory board (A5)
Stylus vibrates at
approx 60 Hz
Recorder board (A8)
Poor recorder
Recorder
performance (frequency
Replace if CRT trace
is good.
response - overshoot)
No ECG signal on
Memory board (A5)
recorder or EXT ECG
output.
O.K.
5-8
CRT trace
/m
Recorder control board
(A8)
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
No annotation, poor
quality printing,
missing dots. LCD
Recorder
Recorder fully closed.
Printhead adjustment
See section 4 for
normal.
alignment procedure.
Unplug P30.
Printhead
Check
between common and
each printhead
element. Aprox. 80 ft.
No annotation.
LCD
Defib control board (AlO)
does not operate.
Printhead dots printed
Recorder control board (A8)
on power up or power
down.
Wrong "SET TO" energy
Recorder control
message printed
(A8)
Strange messages or
missing dots
Recorder control board
board
(A8)
Printhead cable connector
Check connector
(J30)
Wrong language or
relative time printed
Check position of switches
See section 2.4.1
on clock/heart rate board
instead of real time
or no delivered energy
or peak current
information printed.
Clock/heart rate board
Recorder prints TEST
ENERGY with paddles
out of pockets.
Defib control board (AlO)
(A7)
Reed switch or wiring
short.
Recorder prints
delivered energy with
Reed switch or wiring
open circuit.
paddles in pockets, at
any energy setting.
Unplug P18.
Continuity check reed
switch with paddles
out of pockets.
Same as above but
with paddles in
pockets.
Printhead alignment
recorder not properly
Light or no printing
closed.
5.2.7
Indicator Malfunction
SYMPTOM
LOW BATTERY LED
function does not work
SUSPECT AREA
Defib control
CHECKS
board
(AlO)
5-9
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-I
Battery LED on all the
time without power base
/^k
defib control board(A 10)
LOW BATTERY function.
LED does not flash but
1ights when unit is on
power base.
Defib will not discharge
in SYNC mode or will
Defib control board (AlO)
not
ECG digital board (A4)
go into SYNC.
Sync switch or flex circuit
Defib will not discharge
Defib control board (AlO)
in SYNC mode but SYNC
LED flashes
Sync LED does not flash
but defib discharges in
Defib control board (AlO)
SYNC mode
Flex circuit, SYNC LED
Leads and Paddles LED's
does not operate.
CAL signal.
Check through to LED
ECG analog board (A3)
No
As above except CAL
ECG analog board (A3)
O.K.
Malfunctions or
Defib control board (AlO)
deli vered energy or
peak current annotation
problems.
No CAL signal.
Leads and paddles LED
do not operate.
Analog ECG board (A3)
No CAL signal.
Leads and paddles LED's
Cal switch and wiring
O.K.
No QRS beep or alarm
signal.
5.2.8
Memory board (A5)
ECG Signal Problems
SYMPTOM
No Leads ECG signal
CAL and paddles ECG
SUSPECT AREA
ECG leads and connector
wiring
O.K.
Leads/Paddles switch
5-10
CHECKS
SECTION V- TROUBLESHOOTING
Models 78670A /786 71A
78670A-1
No ECG signal from
leads or paddles. CAL
signal O.K. Leads and
ECG analog board (A3)
paddles LED's operate.
No ECG signal from
paddles. Leads ECG
and CAL signal O.K.
No external ECG output.
Patient relay Al-Kl
Leads/paddles switch,
wiring
Memory board (A5)
Recorder ECG O.K.
No external ECG output
or recorder ECG.
ECG O.K.
5.2.9
Memory board (A5)
CRT
Real Time Clock Problems
SYMPTOM
SUSPECT AREA
CHECKS
Clock inaccurate or
Clock/heart rate board
does not operate
(A7)
Cannot enter time set
mode.
Clock/heart rate board
Read instructions for
(A7)
time set mode very
carefully. See
section 3.
Time/date cannot be
set correctly.
5.2.10
Clock/heart rate board
(A7)
Control Problems
SUSPECT AREA
SYMPTOM
Alarms switch or
Clock/heart rate board
alarms problems
(A7)
CHECKS
Memory board (A5)
Alarm switch and wiring
Speaker, wiring
If tone does not
sound at turn-on
or in service mode.
f^
Recorder controls
Recorder board (A8)
Mark Switch
Clock/heart rate board
(A7)
8-second run switch
Switch
and wiring
5-11
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
/^i\
5.2.11
Service Mode
SUSPECT AREA
SYMPTOM
Will not enter service
CHECKS
Defib control board (AlO)
mode
Service switch and wiring
Unplug Pll from
mother board, A2,
Check for switch
operation.
See
interconnect
schematic in
Figure 6-2.
No service ramp-step
waveform on CRT or
recorder
Ramp waveform is
Memory board (A5)
ECG Digital board (A4)
Memory board (A5)
nonlinear
Deflection board (A6)
/^
5.2.12
Battery and/or Power Base Problems
SYMPTOM
SUSPECT AREA
Reduced monitoring time
Battery
until BATTERY LED
flashes.
CHECKS
Replace or deep
discharge battery.
See section 3 on
Battery Capacity
Check.
V Ref shutdown on
defib H.V. board (All)
Measure TP-5 to
ground.
5.29 to
5.51 volts.
See
section 3 for
calibration procedure
(A11-R100)
Battery does not
charge with unit
power base.
Battery
on
13.5 volts.
Power base
Defib control board (AlO)
LED
5-12
Fully charged battery
should measure approx
See section 7
/"•*S|.
SECTION V- TROUBLESHOOTING
Models 78670A /786 71A
78670A-1
5.3
COMPONENT LEVEL
PROBLEM AREA
^
REFER TO
SECTION
PAGE
ECG Monitor
5.3.1
5-14
ECG Analog Board (A3)
5.3.2
5-14
ECG Section
5.3.2.1
5-15
ECG Differential Amplifier Test Proc.
5.3.2.2
5-16
Bias Voltage Check Procedure
on Differential Amplifier
5.3.2.3
5-16
Paddle Contact Indicator Section
5.3.2.4
5-17
Digital ECG Board (A4)
5.3.3
5-17
Memory Board (A5)
5.3.4
5-22
Deflection Board (A6)
5.3.5
5-25
Clock/Heart Rate Board (A7)
5.3.6
5-26
Recorder Board (A8)
5.3.7
5-30
Annotation (78670A only)
5.3.7.1
5-31
CRT Digits
5.3.7.2
5-34
Switch Functions
5.3.7.3
5-36
Recorder
5.3.7.4
5-37
Defibrillator Control Board (AlO)
5.3.8
5-39
Error Message
5.3.8.1
5-39
LCD Display
5.3.8.2
5-40
Paddle Contact Indicator
5.3.8.3
5-41
Defibrillator Charger Board (All)
5.3.9
5-41
Low Voltage Power Supply (A12)
6.3.10
5-52
Pulse Width Modulator (A12-U1)
5.3.10.1
5-55
5-13
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
5.3.1
ECG Monitor
SOURCE
OBSERVED CONDITION
CRT ECG signal
YYYNNNN--NNN
Recorder ECG
NNY--YYYYNNN
signal
Ext ECG signal
YNN
NNN
Beeper (when
CAL is pushed)
---------nyN
CRT Service
---YYNN--NNN
Ramp-step signal
Operation of CAL
---YN
--
in service (and
in AUTO GAIN)
CRT Horiz sweep
NNNYY
CRT Digits
_
_
-
-
-
y
N
Y
N
-
-
-
Go to Line
1
2
3
4
5
6
7
8
9
10
11
12
1.
RECORDER PCA - A8 or Recorder
2.
MEMORY PCA - S/H opamp U18D or S/H switch U14B
3.
MEMORY PCA - opamp U18A; cabling from mother board to ECG output
jack A1-J34
4.
5.
ECG ANALOG PCA - A3
ECG DIGITAL PCA - A4
6.
MEMORY PCA - S/H opamp U17A; S/H switch U14C
7.
DEFLECTION PCA - A6
8.
MEMORY PCA - Ramp generator U17B,C; Ramp sync U3A
9.
DEFLECTION PCA - A6
10. MEMORY PCA - 1MHz osc; divider chain U5,6,7
11. MEMORY PCA - A5
12. ECG DIGITAL PCA-A4
5.3.2
5-14
ECG Analog Board (A3)
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
^
5.3.2.1
ECG Section
SOURCE
CAL signal
OBSERVED CONDITION
No
Yes
No
Yes
Yes
Yes
ECG from Leads
Yes
Yes
No
No
ECG from paddles
Yes
No
Yes
No
Leads/Paddles
LED's operate
No
No
Yes
Yes
Go to Line
SYMPTOM
1.
No CAL signal.
Leads/paddles LED's
SUSPECT AREA
Power supplies
do not operate
CHECKS
+12 and -12 R. (J8
Pins 10 and L). 5 Volt
regulators A3-U53 and
U54.
2.
CAL signal O.K.
Leads/paddles LED's
do not operate
Isolation transformer
A3-T1 and T2, U51B,
U52A, U52B, Q51, Q52
Check for broken
transformer leads.
62.5 KHz clock
signal J8 Pin 2.
Drive signals to T2.
+5D J8 Pin 9.
3.
No CAL signal.
ECG signals and
CAL switch/wiring
leads/paddles LED's
O.K.
4.
No ECG signal from
paddles. Leads ECG
and CAL signals O.K.
5.
No Leads ECG signal
CAL and paddles ECG
Patient relay, leads/
paddles switch, A1-S2
Paddle connectors
Leads/paddles switch
Lead connectors
and cables
A1-S2
O.K.
6.
No ECG signal from
leads or paddles.
CAL signal O.K.
T2 defective or broken
connection to T2.
Follow the ECG
test procedure
outlined below.
Leads/paddles LED's
operate.
ECG amplifier
5-15
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
5.3.2.2
1.
ECG Differential Amplifier Test Procedure
NORMAL OBSERVATION
Measure isolated
Isolated Vcc + 4.2 V
isolated Vee - 4.2 V
Chopper power supply
Select "LEADS" for
ECG SOURCE.
Short
Voltage at junction of
R12, R13 and R23 approx
If voltage O.K., go
"LEADS" inputs
zero to +/-20 mV.
together.
Voltage at junction of
R31, R32 and R29 approx
power supply
voltage.
2.
POSSIBLE CAUSE FOR
ABNORMAL OBSERVATION
INSTRUCTION
zero to +/-20 mV.
and driver circuits.
to 3.
If voltage not O.K.
go to 4.
U2
Pin 6 approx +0.8 V.
3.
Disconnect shorts.
Floating side of T2 should
If observation normal,
Short junction of
R12, R13 and R23
be square wave approx/less
U55.
than +/-4.2 V P-P 32 usee
abnormal, U3.
to +Vcc.
period.
Short
If observation
junction R31, R32
^%
and R24 to -Vee.
4.
U2 pin 6 = 0 volt +/-15 mV
Short C13.
If voltage abnormal,
U2. If voltage normal
check differential
amplifier transistors
01 thru Q6. Check
bias voltages.
5.3.2.3
Bias Voltage Check Procedure on Differential Amplifier
1.
Disconnect J27 ribbon cable.
2.
Short across R18.
3.
Apply power and wait at least one minute to allow the amplifier to stabilize.
4.
If
all transistors
(Al thru
Connect J27 pins 11 and 13 to float ground.
Q6) are operating properly, the bias voltages
should be as noted below:
Ql base and Q6 base
-10 mV
Ql emitter and Q6 emitter
-0.5 V
Q2 base and Q5 base
Junction of R12, R13 and R23
5-16
Vcc-0.55 V
-0.8 V
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
Junction of R31, R32 and R24
-0.8 V
Q3 emitter and Q4 emitter
-0.2 V
Q2 collector and Q5 collector
-0.4 V
If all bias voltages ^re correct, probable cause is LEADS/PADDLES
switch A1-S2.
5.3.2.4
Paddle Contact Indicator Section
1.
Put instrument in service mode.
2.
Lock paddles in storage pockets.
3.
Check for the following waveforms
5pS Sweep
(Refer to paragraph 3.4.2.3).
5pS Sweep
64.9 ohms across paddles
Figure 5-1B
Figure 5-1A
r>-3.3
64.9 ohms across paddles
Digital ECG Board (A-4)
CONDITION
1.
+5
Volts on +5D.
2.
Is +5A normal.
INSTRUCT!!
NO
Check L.V. power supply board (A-12).
NO
Check U53 and U54 on analog board (A3
With no ECG input, J9 Pin N should be biased at zero +/-50 mV.
should drop to approx -250 mV when the CAL switch is pressed.
3.
This
Check CAL switch A1-S5, cabling and
CAL signal on J9
Pin N when CAL
ECG analog board (A3).
switch pressed.
4.
Was service wave
form visible.
YES
Switch to service mode.
YES
Go to
NO
Check U6 Pin 6
line 7
5-17
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
5.
Check memory board as for 4 mS
clock signal.
4 mS clock signal
U6 Pin 6.
6.
Reset pulses at
YES
Go to
line 6
NO
Go to
line 7
YES
Go to line 15
U6 Pin 4.
A/D = 128
2V/Dii
U6-30
5 V/Div.
TP2
IV/Div.
U1-2
2 V/Div.
U5-1
U5-1
WnS/Div.
50[iS/Div.
Figure 5-2B
Figure 5-2A
Ground TPl
7.
Reset pulses at
YE-S
Diconnect ground from TP-1
NO
Go to line
U6 Pin 4.
9.
4 uS clock at
Ul Pin 11.
16
Check memory board (A5) for
NO
clock signal
(See
Figure 5-3).
YES
Continue
a/d = 128
A/D- 255
2 V/Div.
U1-11
2 V/Div.
U1-11
2 V/Div.
TP2
2 V/Div.
TP2
WfjS/Div.
WpS/Div.
Figure 5-3B
Figure 5-3A
TP4 should be biased at zero volts +/-40 mV
approx -210 mV.
10.
5-75
CAL pulse at TP4.
NO
Replace U4.
YES
Continue
CAL pulse is
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-l
Put instrument in SERVICE mode
11.
and MANUAL GAIN.
(Less than 160 mV at MIN GAIN.
Greater than 3.18 V at MAX GAIN).
12. Is there a CAL
signal at TP-5
of the correct
magnitude.
NO
Go to line 18
YES
Continue
Switch to AUTO GAIN.
13.
14.
Range is 0.5 to 2.0 V +/-20%
Is there a CAL
pulse of correct
magnitude on TP5
YES
Go to line 27
5 gain stages.
NO
Go to line 23
15. Are there "tickle"
NO
Replace U6
YES
Continue
for each of the
pulses at TPl.
(4 mS spacing.
After reset greater
than 10 ms spacing),
Connect U3 Pin 12 to ground or
+5D and note output on U3 Pin 10.
16. Check U3C and U3D
17. Output follows input.
NO
Replace U3
YES
Q3 or CI defective
Check logic level on U6 Pins 27,
28 and 29 (should be 101).
13.
19. Logic levels correct.
20. Is U6 Pin 36 high.
YES
Go to line 25
NO
Continue
NO
Defective AUTO/MANUAL switch or
cabling.
YES
Continue
21. Does operation of
CAL switch pull U6
Pin 37 high and low.
YES
Replace U6
NO
Continue
22. Is operation of CAL
YES
Replace Q2
NO
Defective CAL switch or cabling.
switch seen at J9
Pin 12.
23. Is ACG (U6 Pins 29,
28 and 27) stepping
thru this sequence.
100, Oil, 010, 001, 000 then repeat.
YES
Go to line 25
NO
Continue
5-19
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
24. Is U6 pin 36 low.
NO
Defective AUTO MANUAL switch or
cabling.
YES
Go to line 21
Short TP5 to junction of R20, R21
25.
and R22.
26. TP5 zero +/-15 mV.
YES
U2 defective
NO
U5 defective
Short U5 Pins 6 and 7 together.
27.
28. U5 Pin 7 at approx
NO
Replace U5
YES
Continue
NO
Go to line 35
YES
Continue
2.5 Volts.
29. Is there V/F con
version from TP5
to U6 Pin 39.
(Period should be
32 uS +/-4 uS at
U6 Pin 39).
Connect U5 Pin 5 to TP6 (analog ground)
30.
31.
32.
33.
34.
35.
Is TP3 high.
NO
U6 defective
YES
Continue
NO
U3 defective
YES
Disconnect U5 Pin
U5 Pin 5 to Pin 4.
NO
U6 defective
YES
Continue
NO
U3 defective
YES
Board is operating
Does the waveform
NO
U6 defective
at U6 Pin 30 appear
correct. (See
YES
Continue
Is U3 low.
Is TP-3 low.
Is U3 Pin 3 high.
Figure 5-4 and
schematic 6-4).
5-20
SECTION V- TROUBLESHOOTING
Models 78670A/7867IA
786 70A-1
U6-30
U6-24
WpS/Div.
Figure 5-4
36. U5 Pin 1 = 0 +/-15
YES
Continue
NOS
Ground U6 Pin 24 and go to line 38
NO
U6 defective
YES
Q5 defective
YES
Go to line 40
NO
Short U5 Pin 1 to Pin 2. Continue
YES
U5 defective
mV.
37. Does the waveform at
at U6 Pin 24 appear
correct. (See
Figure 5-4 and
schematic Figure 6-4)
38.
Is U5
Pin 1 at zero
+/-15 mV.
39. Is U5 pin 1 at zero
+/-15 mV.
Replace Q5, remove short from U5
NO
Pin 1 to Pin 2.
Ground U6 Pin 24
and go to line 38.
40. U5 Pin 14 high.
NO
U5 defective
YES
Short U5 Pin 13 to Pin 14.
(greater than 3.5 V)
U3-10
Continue.
TP5
i
+
;? ••"1
t "l
*
V
TP3
Q3-C
I ijj | i | j i
TP5
TP3
10mS/Div.
| 100pS/Div.
Figure 5-5
WmS/Div.
Figure 5-6
Figure 5-6 demonstrates the operation of the auto baseline circuit.
upper pair, a sine wave signal is applied to the ECG input.
In the
In the lower
pair, no external signal is applied.
5-27
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
41.
Is U5 Pin 14 low.
U5 defective
1
(less than -3.5 V)
YES
42. Does Ul oscillate
Connect oscilloscope to Ul Pin 13
Ul defective
with period of 16 uS
YES
5.3.4
Q4 defective
Memory Board (A5
SYMPTOM
SUSPECT AREA
Mo ECG signal on CRT
A5-U14 s/h switch
(Recorder ECG O.K.)
(CRT HR digits O.K.
CHECKS
Place in service mode for
ramp-step waveform
Check for ramp-step waveform at
U14C pin 10.
Refer to Figure 5-7A
A5-U17 s/h opamp
Check for same waveform at
U17A pin 1.
TP4, 1 msec, 2 Volts/Div.
Figure 5-7A
U9, Pin 18, lusec, 2 Volts /Div.
Figure 5-7B
No service ramp-step
A5-U9 RAM
Check waveforms at U9
waveform on CRT or
recorder
A5-U4
If waveforms on U9 pins 18,20
bad, check U4 pins 11,12,14,15.
A5-U13 D/A, U17
Check waveforms at 1J13 pins 5-1
and voltages on pins 3,13,14.
If bad replace both U13 and U17
U9, Pin 18, 1 usee, 2 Volts/Div.
Figure 5-7C
5-22
U9, Pin 20, 1 usee, 2 Volts/Div.
Figure 5-7D
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
r
A5-U14,15 strobe
Ramp waveform
not
linear
Connect 2Hz triangle waveform
to leads input (or check with
service ramp step waveform
making observation during ramp).
Check that all data lines toggle
at
A5-U9 RAM
different rates.
If recorder output is good
in REAL TIME mode but bad
in
DELAY mode, RAM is bad or
signals to RAM are incorrect.
A5-U13 D/A, A5-U17
No horizontal sweep
A5-U2 Oscillator
Check waveform at U2 pin 4,5
for lmHz 5V p-p.
A5-U1 Johnson
Counter
Check waveform at Ul pins 1,2,
for 1 usee active high 5 volt
pulses every 4 usee.
A5-U8 or FIXED/
Switch to FIXED trace mode.
(CRT digits ok)
MOVING trace
switch
Address counters
A5-U5B, U6B, U7B
r
1025 counter
If trouble clears, suspect U8.
Check waveforms on U8 in MOVING
trace mode.
Check waveform at U5,6,7
pins 11,12,13. Note-binary
dividers starting with period
of Susec at U5 pin 11.
Check waveform at U5,6,7
pins 3,4,5,6. Note-binary
dividers producing 5 volt
square waves starting with
period of 3 usee at U5 pin 3.
A5-U17
Check waveform at U17 pin 7
for 16 ms square wave 24V p-p.
A5-R28,CR6
Check for same waveform at
junction CR5,CR6 6.5 V p-p
Horizontal ramp
A5-R20,C11,12
Check waveform at U17 pin 10'
for 6.5 V ramp.
A2-U17
Check waveform at TP6 for
6.5 V ramp.
nonlinear
TP6, 2msec, 2 Volts/Div.
TP7, 2 sec, 2 Volts/Div.
Figure 5-7E
Figure 5-7F
5-23
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
No EXT ECG output
A5-U18
(Recorder output
Check waveform at U18 pin 1
(TP7) Figure 5-7F
O.K.)
No R wave beep or
alarm signal
cabling
Unplug Pll from EXT ECG jack to
HV Charger PCA. Check for ramp
step waveform at LI on HV
CHARGER PCA (near EXT ECG jack).
A5-U3
Check waveform at U3 pin 5 for
128 usee active high 5 volt
500 Hz pulses.
U3A, 200usoc, 5 Volts, Upper, Pin 2;
TP1, 1 usee, 2 Volts/Div.
Middle, Pin 5; Lower Pin 7.
Figure 5-7H
Figure 5-7G
A5-U2
Check waveform at U2 pin 2 for
same waveform inverted.
No signal on recorder
or EXT ECG output
A5-U10
(CRT O.K.)
Place in service mode for ramp
step waveform. Check waveforms
at UIO pins 11, 12, 13(TP1 &TP2)
^^„A^^
TP2, 1 msec, 2 Volts/Div.
TP2, 1 usee, 2 Volts/Div.
Figure 5-7J
Figure 5-7K
A5-U14
Check waveform at TP4 for
ramp step (0.5 usec/div 3.5 V
p-p).(See Figure 5-7A).
A5-U18
Check for same waveform at TP5
(1 sec/div 5 V p-p). (Fig. 5-7L)
5-24
-%
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
r
TP5, 2 sec, 2 Volts/Div.
Deflection Board U1A, Pin 1,2 msec, 10 Volts(upper)
R-32, 2 msec, 2 Volts (lower)
Figure 5-7L
5.3.5
Figure 5-7M
Deflection Board (A6)
Many of these tests require the
through an extender board.
SYMPTOM
No vertical gain
DEFLECTI'
PCA, A6,
SUSPECT AREA
Opamp A6-U1D
to be
inserted in
the unit
CHECKS
Check for waveform at Ul
pin 14.
Asymetrical vertical
gain
YOKE
Measure resistance of yoke.
See schematic Figure 6-2.
A6-R13
Check for waveform on R13.
Transistor A6-Q2, Q3
Q4, Q5
Check for positive only or
negative only excursions at
collector Q4, Q5 to ground.
With no signal input-measure
Vertical crossover
distortion
Transistor A6-Q1
No horizontal gain
Opamp A6-U1A (Fig. 5-7M)
Check waveform at Ul pin 1
Asymetrical horizontal
deflection
Transistor A6-Q7,
Q8
Check for positive only or
negative only excursions
voltage from base Q2 to base
Q3-should be 1.0 volts.
on R19.
Horizontal crossover
Transistor A6-Q6
distortion
With no signal input-measure
voltage from base Q7 to
base 08 should be 1.2 volts.
No brightness
r
CRT filament
Turn power off. If dot appears
briefly on CRT, the anode HV
and CRT are O.K.
+200 V supply
Measure voltage at P3 Pin A
(+180 to +210 volts).
5-25
SECTION V- TROUBLESHOOTING
Models 78670A/7867IA
78670A-1
R13 or R19 burned
Check power supply
out
voltages.
Replace resistor and Ul.
Measure cathode and grid
Intensity pots
volts
Remove anode connector and
arc to CRT shield.
Anode high voltage
WARNING:
+5000 VOLTS
Beam doesn't turn off
Opamp A6-UlC(Fig. 5-7N)
Check waveform at Ul pin 8
Can't lower intensity
Opamp A6-U1B
Check waveform at Ul pin 7
Deflection Board U1C, Pin 8, 2 msec, 20 Volts/Div.
Figure 5-7N
5.3.6
Clock/Heart Rate Board (A7)
SYMPTOM
SUSPECT AREA
1.Clock inaccurate or
does not operate.
Clock battery
A7-BT1
CHECKS
Battery voltage should be
greater than 2.5 volts.
2. New battery
voltage pulled
CIO, C16, C26, C27,
C28, C29, shorted
below 2.9 volts.
and SCR latched IC's
Remove jumper wire, Wl.
Connect microampmeter
between TP4 and TP5. Typical
U7, U8.
current
less than 10 uA at
room temperature (may be as
high as 60 uA).
U6, U7, A8-U1 con
TPl for 2048.00 Hz +/-0.005 Hz
nection to mother
at 25 degree C.
board, A2.
3. Clock not
or cannot be
running
Yl, C8, C9, U7
Externally trigger oscillo
scope on power switch.
adjusted.
U6 Pin 6 should go low for
120 or 600 msec.
after power on.
Figure 5-8).
A8-U1, A8-Y1, A7-U6,
A7-U5, A15-U1, A15-U2
5-26
One second
(See
Connection between A8-U1
Pins 35 and U6 Pin 6.
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
For the following checks have oscilloscope set as previously described).
If level
does not
change, go to step 4.
U8 Pin 6 should to high
(2.9 V) for 20 or 600 mS.
(See Figure 5-8).
Q6, R53, R54, U6
Q6 collector should be low
when U8 Pin 6 is high.
high (2.9 V) or low
U6, if U8 Pin 6 does
not charge and IJ6
(0 V).
does not go low at
U6
U6
20
U6
4. U8 Pin 6 is stuck
all.
Pin 22. If U8 is high,
Pin 22 should go low for
mS.
If U8 Pin 6 is low,
Pin 22 should go low for
600 mS.
5.
U8 Pin 6 is not
Q3, R47, R31
Look
at IJ6 Pin 22
high or low, or
U6 Pin 22 goes low
following: (a) base of Q3
for a time different
from 20 or 600 mS.
Pin 22 is high and near zero
simultaneously with the
should be +0.6 V when 116
when U6
is low.
(b) Collector Q3 should be
as shown in Figure 5-9.
C3, C18, R28, R27
U6-6
2 V/Div.
-:
.
•
J
T
r
2 V/Div.
T
[
U8-8
:c
T
Delayed Sweep 20mS/Div. *
"Approximately one second has elapsed before start of sweep
Figure 5-8
5-27
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
PWM
2 V/Div.
176-22
;|:-;:;
jlft-
-!•
-.-•-- j , .-,-;-
^
2 V/Div.
-:-:-:-:--:-:-:-:-
-H+tj
Q3-C
-:-:-:-:-£:-:-:-:- -;-:-:-:J.
Delayed Sweep 20mS/Div.'
*Approximately one second has elapsed before start of sweep
Figure 5-9
6. "Sleep" line P12
Pin H stuck low.
Connections Al to A2
and A2 to A7.
Q4 and Q5 have parallel
connected collectors so that
one could fail without being
able to tell
Q4, Q5, R25, R26,
R27, R28, R50, R51
which one.
Q4, Q5 collectors should be
+5 volts when instrument is
idle and 0 volts when Q3
collector is above 4.5 volts.
Place shorting jumper across
base and emitter of Q2.
Collector should be 2.6 volts
If close but not
With jumper in place, measure
correct, replace any
of R18, R20, R21 and
across R21.
It should be
0.5263 times the measured
Q2.
voltage of 5 volt supply.
Q2, R18, U8
Remove jumper.
collector.
Check Q2
Should be 2.6
volts when Q3 collector is
about 4.5 volts.
(See Figure
5-10).
CR13, R24, C12, R23
U9, CR2, CR8, R23,
R22, R19, U8.
5-28
Voltage across C12.
Should
be at system battery voltage.
DC voltage between TP2 and
TP3 should be 2.490 volts
^
SECTION V- TROUBLESHOOTING
Models 78670A/7867IA
786 70A-1
r
'
2 V/Div.
U2-C
:
••••[•
1
j.'
-!—!-,-.-
.-.-.-.
1
2 V/Div.
-•-•-
, i .-;-»- -!-;-}-!-
-[-
--I
;...
|
k. i
f
U3-C
£i_ ... ?L_J
Delayed Sweep 20mS/Div. '
Figure 5-10
+/- 0.0005 volts (use 5-1/2
digit DVM). Adjust R40.
If not, replace R22.
Turn off power.
TP2 should
be about 0.6 volts.
Replace jumper base to emitter
Q2. U8 Pin 6 should be high
U8
(2.9 V).
Remove jumper.
U8
Pin 6 should be low.
Cll, R53
On power up, 100 mS after U6
Pin 22 goes low, U8 pin 6
should go high for about
20 mS. (See Figure 5-11).
R48, CR15, C19, R43
If after replacing
these components, U7
U7 Pin 5 (chip select) should
Pin 5 sti11
follow 20 mS pulse at U8
Pin 6.
does not
follow, replace U7.
Trigger on
ue-22
2 V/Div. •
U6 Pin 22.
edge of pulse on
Look at U7 Pins
1-4, 5, 8, 9 and their
corresponding lines !J6 Pins
1-5, 20, 23. Compare the
waveforms with those in Figure
2-31 and 2-32 of the Theory
of Operation. If the waveforms
at U6 are bad, replace U6,
possibly A8-U1. If the
waveforms are good at U6, and
bad at U7, replace any of R39,
U8-6
R52 and the capacitor and
Schottky diode on the affected
1ine (any of CR9-14, C20-25).
If waveforms are good at U7,
Delayed Sweep 20mS/Div.
Figure 5-11
1-29
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
replace U7. If clock stilT
does not work, replace any of
U6, A8-U1, A15-U1.
,/^
Check connections on mother
board A2.
5.3.7
Recorder Board (A8)
NOTE: Recorder control board (A8) and Heart Rate board (A7) have some
interaction with circuit boards A4, A5, A6, AlO, A15.
Interconnection is through
mother board (A2).
CHECKS
SUSPECT AREA
SYMPTOM
A8U1 microcomputer
Recorder won't run
+5 volts at Ul Pins 5, 26,
40.
or won't shut off,
no digits on CRT,
Zero volts at Ul Pin 7.
+5 volts at Ul interrupt
line, Pin 6. 400 kHz pulses
alarms don't work
or won't enter
Time/Date set mode.
at Ul Pins 11 and 9 if
oscillator running.
If not,
replace Yl, C12, C13, Ul.
A8 tickle circuit
Check A8U1 or A15U1 Pin 4 for
A8U5, Q6, Q7, Q8
negative going pulses as in
Figure 5-12. If pulses are
seen, any of U4, Q7, CR6, C9,
R24, R25, CR4 could be bad.
Check U4 pins 11, 12 as
U4 Pin 11
^%
described below in "No
annotating or missing dots."
If U4 good, check base of
Q7 for pulses synced with U4
Pin 11 as in Figure 5-13.
--
+44
4+ +44+ +H4
If no pulses at base of Q7,
replace C9, R24, R25, CR6,
/
4+
444-
44-
Q7.
4+ +44+
APP1ROX
ImS
OV
fe^HTTTS
5mS/Div.
Figure 5-12
If pulses seen at Ul Pin 4
are wrong duty cycle and/or
frequency, replace CIO, R20,
R22, R23. Short base to
emitter of Q7.
Ul Pin 4
should now appear as in
Figure 5-12.
If not, check U5B Pin 2.
Should be 2.5 volts.
If
not, replace R18, R19, CR14
Cll.
If it oscillates as in
Figure 5-14 or oscillates with
a 50% duty cycle at approx
25 Hz, replace CRll.
5-30
/^%
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
If it does not oscillate at
all, with base and emitter
Q7 shorted together, short
U5 Pin 3 to ground. Pin 1
should be at -12 volts.
I1
H++
+H
44H
4+ 44-
::
72V
+444
/PPROX
Short Pin 3 to +5. Pin 1
should be at +5 volts. If
not replace U5.
TTT
^
When U5 Pin 1 is at +5, Q6
collector (Ul Pin 4) should
be low (0 volts), when U5
::l-2nS
1mS/Div.
Pin 1 is at -12 volts, Q6
Figure 5-13
collector should be at +15.
If not, replace Q6, R20,
R21, CR10.
A8Q8, AlO, A8 or
Check level of "sleep" line
A15 Ul Pin 4 held
from AlO. If held low,
repair AlO or A2.
low.
If "sleep" high, check voltage
across R26.
If not close to
zero, replace Q8, R27
^\
Short "sleep" line to ground
1111
1 1 1 1
11II
T
ill
11 11 11 U
1 'nl
I I I11
!
1
mm"
JIM
MM. 'Mil
1 M 1
ii
Illy 11
till
mi
•
collector of Q6 should also be
at ground. If not, replace
R26, Q6.
11 •
1111
OV
After oscillations are
obtained (see Figure 5-12),
remove short from Q7 baseemitter. Trigger oscilloscope
on power switch. Look at Ul
500liS/Div.
Figure 5-14
Pin 4 (Q6 collector) on
power up.
Should be low for approx 100
mS after power up. If not,
replace Cll, C18, R19, CR14.
5.3.7.1
Annotation (78670Aonly)
SYMPTOM
SUSPECT AREA
Dots printed on
Printhead protection
network A8Q9, QIO
power up.
CHECKS
+15 volts at emitter QIO.
Trigger scope on power switch.
Look at collector Q9. See
Figure 5-15.
If collector Q9 stays at +15,
5-31
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
replace any of Q9, C21, R47.
If collector stays at -12,
replace any of Q9, QIO, R48,
1
IIII
fill
If 111
111
R47, C21.
1111
MM
1111
MM
MM' "mm
Ull,
.Mil
1MM
1 11
1II 1
MM
1 M 1
IIII
lilt
MM
OV
If collector Q9 stays high,
much less than 100 mS, replace
CR14, R46, R47, C21, C20.
I
P( )WEF
ON
If Q9 collector waveform is
50mS/Div.
Figure 5-15
Dots printed on
power down.
Same as above
good, and +15 does not appear
at the collector of QIO, with
the printhead connected,
replace QIO.
Same as above. See Figure 5-16
for power down waveform at
collector Q9. If waveform
is good, replace QIO. If
not, replace CR15, C20.
If collector Q9 stays low
for much longer than 50 mS,
replace C20, CR15.
No annotation
Sane as above
Same as above.
Recorder
Be sure recorder door is
/^s%
fully closed.
Missing dots
Printhead adjustment
Check alignment. See
section 4.2.20 for procedure.
(Note: One full turn of the
adjustment screw can move the
printhead out of the print
area.
4+44
POV\
E4444 4444 +44+ +44+ 4445- OV
+H4
CiFF
0-3C mS
"H P
10mS/Div
Figure 5-16
5-32
/^%
SECTION V - TROUBLESHOOTING
Models 78670A/7867IA
78670A-I
Reinsert cable. Replace
Flex cable
connector A8-J30
connector.
A8U2
When trying to print, inputs
to U2 Pins 1-6 should be
j
Tl
inverted at outputs (Pins
16-10). If not, replace
U2.
5V/Div.
-:-:-:--:- -:-:-:-:•-
-:-:-:•
;-
....1
T
i
"i"
"i"
T
5 V/Div.
-:-:-•-•-
—'-'-'-
^-'-'-,-
Figure 5-17
- ' - ' - • - • - -•-'-:-:-
1"
i
-'-
5 V/Div.
. . . .
-
-:-:-:-:-
i •:-;-:-;-
-:-:-;-:-
1
.
5mS/Div.
Enable circuits
A8C1, Rl, R2, R3,
CR1, A8U4
Look at junction of Rl, R2
R3, CR1 with 10 Mfl scope
probe.
See Figure 5-17,
upper trace for waveform.
If waveform at U4 Pin 11
(Figure 5-17, center trace)
good, replace CI, Rl, R2,
R3, CR1.
If U4 Pin 12 good, Pin 11
bad, replace U4.
A8U3, U4
When common lines of U3 and
U4 are low (see Figure 5-17,
lower trace) outputs of U3 and
U4 (U3 pins 10, 4, 11, 3 and
U4 pins 4, 10, 3) should be
inverted from the inputs,
(Ul Pins 12-18).
If not,
replace U3 or U4.
Printhead failure
Measure resistance at flex
cable end between common
(wide conductor) and printhead elements (narrow
conductors). Should be
78-97 a on all 7 resistors.
5-33
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Check for intermittent failure
of flex cable at overlay
termination due to bending
while inserting cable into
connector.
Check continuity of LCD
Wrong "SET TO
ENERGY" printed.
No discharge
information printed,
A8, AlO
Strange messages
A8U1 Pins 6, 27-30
Check for intermittent
shorts.
Printhead cable
Check connection, reinsert
connector A8-J30
or replace.
A7S1 and R5-8, A7U1
Check operation of switches.
lines (A8 Pins 27-30)
from A8 to AlO.
Check for
shorts.
printed or missing
dots.
Wrong language, or
relative time printed
SI should short A7U1 Pins 2,
4,17, and 23 to ground when
closed. Logic high when open.
instead of real time,
or no delivered energy
or peak current
information printed.
If good, replace A7U1.
(See
section 2.3.12 for switch
operation).
Poor quality printing
Printhead adjustment
Check printhead resistance
as above. Adjust printhead
as in Checks and Adjustments,
Section 3.
5.3.7.2
CRT Digits
SYMPTOM
SUSPECT AREA
No CRT digits.
Possibly bright
A8,A7
dot in center of
CRT.
Baseline
trace visible.
A7U5d
Or bad digits
A7U1, U2, U3, U4
CHECKS
Check chip selector line for
high level, A8U1 Pin 35,
A7U5d, A7U1, Pin 6.
Check for pulses at Ul Pins
13-16, 18-22, 1. If none,
replace Ul.
Check that waveform at U4
pins 5 and 7 are identical.
Pins 3 and 1 are identical.
If not, replace U4.
Check for signal at U2 and
U3 Pin 4. If none, replace
U2 or U3. See Figures 5-18
and 5-19.
5-34
SECTION V - TROUBLESHOOTING
Models 786 70A/78671A
786 70A-1
0.5 V/Div.
fa
Figure 5-18
1
2m S/Div.
Figure 5-19
r
500pS/Div.
Check intensity line A7U1
Pin 21. When low, CRT beam is
blanked. Line should go high
Bean blanked
during signal. (Figure 5-18
and 5-19).
A7U1.
If not, replace
Check A5 memory
board.
A5-memory board
Digits flash,
characters printed
A-6 deflection
If no baseline trace. Also
Check A8U1 to A7U1, U6
A-8/A-7/A-2
connection A8U1 Pins 21-25
A8, A5
Check 16 mS line A8U1
Pin 39,from memory board
PCA A5.
Should be square
wave with 16.4 mS period.
wider than normal.
Wrong heart rate
displayed and
r
A4-ECG digital
board
A4 not detecting R-waves
correctly.
printed.
5-35
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
A8, A4
Check R-wave line A8U1
Pin 1 from A4 for negative
going pulses. When using
ECG simulator, pulses should
coincide with QRS complex.
A15
If pulses good, replace A8U1.
5.3.7.3
Switch Functions
SYMPTOM
Alarm switch, alarms
SUSPECT AREA
CHECKS
Alarm switch, cable
Check A7U1 Pin 5 for
A7 clock board
transitions when actuating
switch. If none, replace
RIO, R13 switch, cabling.
A7U1
Check if Ul Pin 3 is low
during alarm condition.
If not, replace R9, Ul.
A5 memory board
Check for approx 500 Hz
pulses at A8 edge pin D
("Beep").
A7U5A, A7U5B, A7U5C,
A7Q1, Rll, R12, C7
Check if outputs U5 (Pins
4,10,11) are inverted from
"Beep" signal during alarm
CR1
condition.
If not, replace U5.
If output U5A, B and C are
good, then check collector
Ql for sync'd translations,
If none, replace Rll, RIO,
Ql.
If collector Ql is good,
replace C7, CR1.
Speaker
Replace speaker, check for
system interconnect short
to ground on A8 edge Pin E
("SPKR").
5-36
Recorder/Speaker
Check connections to
cable
speaker.
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Recorder run switch
Switch, cable, A8,
Check A8U1, Pin 31 for
doesn't work or
recorder won't run
or won't shut off
recorder board
transitions when switch
Mark switch same
actuated. If good, replace
Ul. If not, replace R29,
C19 switch, cable.
Recorder
Check recorder as
described below.
Same as above
Check Ul Pin 32 for
transitions as above.
R29, C18 switch, cable.
If good, replace Ul.
8-SEC RUN switch
Same as above
Same as above
Check Ul Pin 33 for
transitions as above.
C29, C17 switch cable.
If good, replace Ul.
Service switch
Same as above
(won't enter Time/
Date set mode)
Check Ul Pin 37 for
transitions as above.
R29, C16, switch, cable
If good replace Ul.
0^
5.3.7.4
Recorder
SYMPTOM
CHECKS
SUSPECT AREA
Recorder won't run
or won't shut off.
A8Q3, Q4, R13-17,
R41, A8 or A15 Ul
Check Ul Pin 19 for
transitions when MARK
Digits on CRT good,
printing good when
Pin 19
button pressed (to run
recorder). If none,
replace R13, R41, Ul.
recorder runs.
Check collector and base of
Q3 for transitions (4 BAT, to
0 volts on collector). If
none, replace Q3, CR5, R14,
R17.
Check collector and base Q4
for transitions (+ BAT,
-5 volts on collector). If
none, replace Q4, R15.
Check A8 edge Pin 1 for
transitions (0 volts to
approx +6 volts when
recorder is connected). If
none, replace C3, CR8, R16.
Recorder
Replace
5-37
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Stylus moves with
A8Q5, Q3, Q4
Check gate Q5 for 0 volts.
If positive, replace CR7,
R41. If negative, check
Q3, Q4, Ul as above. Replace
Q5.
A5-memory board
Check for signal at A8 edge
recorder off
Stylus won't move
with recorder on
Pin U
A8Q5, Q3, Q4
Check if gate Q5 is at -5
volts. If at -12 volts,
replace R42. If more
positive than -4 volts,
check Q3, Q4 Ul as above.
Replace Q5, replace RIO,
Rll.
Stylus pinned
or large stylus
Ql, Q2, U5a
offset
Check collector Ql at +5
volts. Collector Q2 at -12
volts, no signal. If not,
replace Ql or Q2, R4-9.
Replace U5, RIO, Rll
CR12, R43, R44
Check anode CR12 for -5.6
volts. If not, replace
CR12, R43, R44.
A5 memory board
Check signal from A5-memory.
Board has approx 2.56 volt
DC offset.
Stylus vibrates
approx 60 Hz
A8CR13
Recorder won't run
Recorder cable
Replace
Slight movement on
pressing MARK switch.
Mo movement on
pressing 8-SEC RUN
switch.
Automatic run on
A8, AlO
operate.
Automatic run, on
charge, does not
operate.
Check LCD lines A8U1 Pins
27-30 for continuity, shorts
to ground, etc.
charge does not
A8, AlO
Check LCD lines A8U1 Pins
27-30 for continuity, shorts
to ground, etc.
Check A8Q3, Q4, Ul as
described above.
Poor performance
frequency response
and overshoot.
5-38
Recorder
If CRT trace is good, replace
recorder
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
5.3.8
Defibrillator Control Board (AlO)
5.3.8.1
Error Messages
Error messages on LCD (when there's an
error number and energy alternately).
SYMPTOM
error message, the
SUSPECT AREA
Note:
flash the
CHECKS
UIO bus (Port 0)
UIO or U4
PO error
LCD's will
This error may not show up as PO error on the LCD's
because the bus has been effected.
PO error
.Defib control
board
1110 pin 14 or 25
(AlO)
PI error
r
U14
2.5 V ref
Power supply board
(A12)
+5
Defib H.V. board (All
+5.4 V ref
U12 or U13B
Compare waveform with
V
Figure 5-20
5 msec No Charge on H. V. Cap.
Figure 5-20
Ull, A/D converter
P2 error
200 usee
Figure 5-21
Ull, pin 19 300 KHz
Compare waveform with
Figure 5-21
P3 error.
Cap
Defib HV board (All)
Vcap monitoring circuit
overcharged.
5-39
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
P4 error.
Imbal
ance detected
HV defib section
Leakage to ground
between Vcap 1
and Vcap 2
HV cap
Shorted HV cap
Patient relay
Arcing in relay
Safety relay can't open.
Ul pin 13 <0.5 V
Defib HV board (All)
PWM charging circuit
HV cap
Cap is leaking or shorted
P6 error
Patient relay
Arcing in relay
P7 error.
Safety relay stuck
Unexpected energy
open
Ul pin 3 near SW BATT 2
voltage
P5 error.
Can't
charge
detected on cap
Ul pin 13 <1.5 V
Defib HV board (All)
Safety relay driver
PWM charging circuit
Low battery
Can't
P8 error,
charge
P9 error
Defib control
board
R72 adjusted out of range
(AlO)
HV cap
5.3.8.2
LCD Display
SYMPTOM
SUSPECT AREA
No "HP", "888" or "P"
Microprocessor (UIO)
or "Tickle Ckt" (U6)
errors at turn-on.
1 msec
Figure 5-22
5-40
Out of tolerance
CHECKS
Compare waveforms with
Figure 5-22
0.5 msec 64.9 ohms across paddles.
Figure 5-23
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
5.3.8.3
Paddle Contact Indicator
SYMPTOM
SUSPECT AREA
With 64.9 ohms
U2 or UIB
across paddles,
bar display has
CHECKS
Compare waveforms with
Figure 5-23
less than 9 LED's
lit
ECG Analog board (A3)
5.4 Vdc at J17, pin B
Patient relay
Short C25 on ECG analog
board (A3). Should measure
less than 3 ohms across
paddles
5.3.9
Defibrillator Charger Board (A-11)
SYMPTOM
P4 error.
SUSPECT AREA
No defib
Mother PCB
CHECKS
Check fuse, SW BAT 2
charge (no sound, no
LCD count at any
energy setting).
All-Fl greater than 10
volts both ends of ground
is normal.
P5 error after
Defib charger (All)
If fuse blown, check Q5,
Q2 and Ql output transistors
for shorts.
Relay All-Kl
If less than 10 volts with
battery, check Kl circuit
If less than 10 volts with
Power Base, check J47. If
greater than 10 volts, check
Power Base V-Reg circuit
(See Section VII of this
manual).
J19, pin 8 should drop to
less than 1.0 volt during
CHARGE if normal.
If greater than 1.5 volts,
check defib control
board
(AlO) CHARGE circuits and
cables.
TP8 should be at low voltage.
If not, Low Battery Shutdown
is keeping Q9 on.
5-41
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Check for low V-Bat or V-REG.
If normal, check J19, pin 11
for 5.4 V +/-2% (5.29 to
5.51 volts).
If normal, check UIB circuit.
U3, pin 9 climbs from approx
0.5 volts to greater than
2.0 volts normally during
CHARGE.
If less than 1.0 volts,
check Q9 and C105 for shorts.
A11-U3
Normal TP9 from 4.6 to 5.4
volts.
If less than 4.6, check
for no Vc on pin 15 or
short circuit load on this
+5 V reference.
Check U3, pin 7 for 8 kHz
sawtooth waveform, replace
U3 if missing.
Before
should
volts,
During
/5^!k
charging, U3, pin 2
be approximately 2.5
pin 1 at 0 volts.
charge, pin 1 should
rise to less than 2.5 volts
or safety shutdown will occur.
Check R35 for open circuit
or cold solder at pads, which
cause immediate current
shutdown, pin 4.
Normal:
U3 pin 9 climbs to
greater than 2.0 volts and
TP3 output approximately 10
volts p-p during charge.
If no output, measure
resistance, TP3 to ground.
If short, check Ql. If
500-600 ohms, replace U3
(open circuit output).
If 10 volts p-p and duty cycle
approximately 90%, check Q2
for open base.
Or Q2 and Q5
collectors for V-raw. Possible
open circuit to Fl.
5-42
Normal
/•^k
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
waveforms Fig. 5-25A through
D, Fig. 5-26A and B.
Or check Q5 for open base.
No sound, no
Apex paddle circuit
Check J15, paddle switch
operation.
Defib HV components
If LCD count-up, possible
open circuit to HV defib
error code.
No defib charge.
Very faint sound,
cap.
WARNING:
DANGER:
HIGH VOLTAGE
Tl OUTPUT HV LEADS
CONNECT TO POTEN
TIALLY LETHAL HV
DEFIB CAPACITOR.
SHORT HV CAPACITOR.
TERMINALS BEFORE
TESTS.
FOR FIGURES 5-24 THROUGH 5-30 REFER TO
PAGES 5-45/5-46 (FOLD-OUT)
Normal:
Resistance at HV cap
terminals approximately 10
kilohms (safety load resistor)
CAUTION:
RECONNECT HV Tl
LEADS TO HV CAPAC
ITOR BEFORE CHARGING
DEFIBRILLATOR.
If no LCD count-up, possible
HV transformer or rectifier
short.
Note Figures 5-24,,
A to D vs E. Also, HV leads
to each other and ground over
20M ohms with DMM if VDMM
less than 5 volts.
Defib charges to low
energy settings only,
with frequent re
charge after reaching
preset. May time out
with P5 error if
unable to reach higher
settings after 10 sec.
HV safety relay
Charges to 5 joules with
frequent refresh but unable
to reach 10 joules:
probable
failure of safety relay to
open J21, pin 4 normally
greater than 9 volts during
charge. If not: check Q4
operation, drive to relay
coil.
Check J19 pin 16 normally less
than 2.5 volts during charge.
If not, check defib control
board (AlO).
5-43
SECTION V- TROUBLESHOOTING
Models 78670A/78671 A
78670A-l
If higher values of energy,
but still limiting, check
for possible safety relay
/«^m
arcing during charge (may
give P5 or P3 error). A long
attempt to charge should
produce noticeable heat on
safety resistor plastic
cover.
HV circuit
Possible HV transformer arc.
Note R35 normal vs shorted
transformer or HV rectifier
waveforms. See Fig. 5-24,,
A to D vs E. Also, HV leads
to each other and ground
should be over 20 M ohms with
DMM if VDMM less than 5 volts
(may get P5 or P3 error if
layer arcing, P4 error if
arcing to ground).
HV monitor circuits
Check with energy meter at
lower energy settings. If
out of calibration, adjust
A10-R72, recheck at high
energy level. Refer to
Section III for procedure.
U3 pin 2 voltage greater than
pin 1 voltage (approximately
2.5 volts normal). If voltage
at pin 2 equals pin 1 at less
than 360 joules, check error
amp circuit, R141 and R142.
No defib charge.
4.
HV circuit
Check
for HV shorts: HV defib
capacitor (usually follows
loud bang when capacitor
shorts during charge).
Near normal sound
but little or no
LCD count-up.
Charger shut off
after about 10
seconds with P5
Flyback waveform slope normal.
See Fig. 5-24, A to D normal,
error.
E if short.
HV defib cap Al-Cl
WARNING:
HIGH VOLTAGE
Uncover defib capacitor
SHORT HV CAPACITOR TERMINALS
WITH SCREWDRIVER BEFORE
MEASUREMENTS OR DISCONNECT
TO DISCHARGE HV.
5-44
/^\
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-4
r
Figure 5-25
Flyback charging waveform,
TP1, 20V/Div., 20 usec/Div.
A: Battery only
Approx. 100 J on LCD
Battery only
Approx 300 J on LCD
C: Power Base
A Approx. 100 Jon LCD
D: Power Base
Approx. 300 J on LCD
r
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Check resistance between HV
capacitor terminals. 10 K
ohms is normal.
If short,
remove leads to isolate short
and replace defective part.
HV transformer All-Tl
If not HV capacitor, measure
HV leads to HV transformerrectifier.
Should measure
over 20 M ohms wire-to-wire
and either wire-to-ground if
DMM ohms test voltage less
than 5 volts.
Inaccurate/ineon-
HV circuit
si stant output,
especially at high
energy settings.
Maybe P4 errors.
Perform calibration procedure
with defib energy meter (refer
to Section III). If output
still non-linear or erratic,
may be due to shunt leakage
to ground, in either HV lead.
Patient relay Al-Kl
WARNING:
EYE PROTECTION
REQUIRED.
Inspect HV patient relay,
replace if badly discolored
internally or if very bright
discharge flash.
Above high energy
Patient relay Al-Kl
Same check as above.
problems and/or some
P6 errors (10% drop
Safety relay A1-K2
in VHV).
Best check is to look at both
HV metering amplifier output
on dual channel storage scope
during charge to 360 joules.
Normal are smooth lines to
360 on LCD, than horizontal
traces until discharge by
operator or timeout.
Sudden changes indicate
probable arcs in HV relay.
HV transformer
Same as above checks.
Monitor circuits
Check monitor circuit for
intermittents, including AlO
(defib control board)
components, including A10-R72
for poor wiper contact.
5-47
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
//*^K
Inaccurate/ineon-
I-Pk circuit
Standby saturation of output
to defib control board (AlO).
si stant output only
at low energy setting.
May show P3 error.
Test defib at 100 J while
measuring voltage J18 pin 9 to
pin 10. Should read schematic
values after defib, slowly
drift down.
If there is drift
up to over 6 volts, check U4a,
Q21 for excess leakage.
Incorrect charge
time to 360 joules.
May show P5 or P8
U3 shutdown circuit
Check U3 pin 9 charge start
waveform. If voltage rise
much faster than 1/3 second,
check Q9, C105 circuit.
Defib inverter
Normal charge time: 7 sec on
Power Base, 9 seconds with
fully charged battery.
error.
Perform calibration,
to Section III.
Refer
Check either battery or
Power Base if one is OK, other
is not.
S^lh
If audible on/off, check low
battery/V-reg circuits.
If normal times at lower
energy, very long at 360,
check waveform at TPl for
possible HV transformer
short — see Figure 5-24E.
If wery little decrease in
charge time from 1/2 to 1/4
turn position of R34, 1/2 of
U3 output may be inoperative.
Waveform TP3 should go from
approximately 50% to 90% duty
cycle if fuse All-Fl is
pulled. If 50% max, replace
U3. Figure 5-27.
No I-Pk or delivered
energy reading.
I-Pk circuit
Operate in internal test mode,
100 J. Measure voltage at
J19, pin 9 to pin 10 after 50
ohm discharge. Compare with
voltage on schematic, Section
VI (All).
S^%\
If normal, check defib control
board (AlO) operation.
5-48
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
If absent, check waveform back
through circuit to determine
loss and faulty parts (UlA,
Q21, U4A, Q6, I-Pk XFMR).
(Figure 5-28 through 5-30).
I-Pk and delivered
I-Pk circuit
energy inconsistant.
Perform voltage and waveform
checks listed above.
If normal, check defib control
board (AlO) operation.
If irregular output, check
for proper A11-Q6 reset.
Observe HV patient relay.
Replace if badly discolored
or yery bright discharge
flash at 360 joules - possible
EMI source.
I-Pk always high
Do above voltage and waveform
checks.
If normal, check defib control
board (AlO) operation.
If J19 pin 9 to pin 10 voltage
is greater than 5 volts, check
back through circuit for point
of voltage clamp, faulty part.
HV patient relay
will not discharge
Patient relay circuit
Charge reaches preset energy
level, but discharge paddle
switches will not discharge
system.
SYNC/DEFIB switch
System is in SYNC mode, with
no ECG leads input waveform.
Relay drive circuit Q3, CR8,
J21, etc. defect. Check wave
forms, Figure 5-28.
Check discharge switch
voltages, J15, J16, J19.
Defib control PCB (AlO).
input pulse, Jl pin 13.
No
Charge stops before preset
level
is reached.
Check for low battery voltage.
5-49
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Check inputs to U3 error
amplifier.
Dempsey discharge
Defib inductor
waveform is RC
Measure DC resistance of
defib inductor.
Should be
greater than 9 ohns.
decay instead of
damped sine wave.
WARNING:
Entire unit dead,
V-ref, shutdown
ECG and defib
HIGH VOLTAGE.
Battery voltage normal.
(12 volts nominal).
Check A2-F1 and F2 on mother
board (A2).
Check power switch on ENERGY
SELECTOR.
Check TP5 for 5.4 volts
+/-2%.
If high, adjust R132 for
5.4 V, TP4 to J19 pin 10.
If high over whole R132
range, check U5 circuit.
Short monitor time
and/or reduced defib
V-ref, shutdown
Check battery, See Section III
count before LOW
Low battery
Perform voltage ref check
BATTERY indication
**%
noted above.
and/or shutdown.
Check LOW BATT LED drive
circuit, defib control board
(AlO).
Monitor OK.
No
Check UIB circuit.
defib charge.
Battery does not
charge (cold after
overnight, on charge,
V-Bat circuit
Approx 0.6 volt across CR9
normal. Check battery for
cell reversal. Fully charged
battery open circuit voltage
should be appproximately
may also be noted if
no current to battery.
13.5 volts.
A11-CR9
If greater than 1.0 volts
across CR9, then CR9 open.
If less than 0.5 volts across
CR9, no Power Base output
(pull P48 and test) See
Section VII.
5-50
/^%
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
p
Open circuit to battery.
Short circuit, line to ground
(isolate by connector discon
nects).
No CHARGING BATTERY
LED.
V-BATT circuit
Power Base on.
J48 greater than 10 volts
normal, then open circuit
to LED.
Defective LED.
If J48 is less than 10 volts,
check for dead or shorted
battery (unplug battery).
No Power Base output (pull
P48 and test). See Section
VII.
Q22 circuit.
Monitor and defib
Battery or V-reg
dead.
Power Base circuits
J44, 10 to 13 volts normal
range with battery.
11.5 to 13.5 volts normal
range with Power Base.
Check J19 pin 3 for about the
same voltage. Power switch
on. If not, check fuse A2-F2.
Also check A2-F1 on mother
board (A2).
If voltage normal, check
Low battery shutdown/V-ref
circuit A11-U5, UIB.
If J44 less than 10 volts.
If
battery only, check battery
and P43, P44 jumper con
nections, PCB wiring.
If Power Base only, check it.
See Section VII for Power Base
information.
5-51
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-l
If the single turn loop of
After replacing a
component in the
defibrillator high
voltage circuit that
wire was removed from the
also involves the
transformer, it was wound
in the wrong direction when
it was replaced.
discharge current
transformer, T2. No
discharge energy is
The transformer output pulse
must be positive. This can
be checked with an oscillo
displayed or printed.
(The patient relay
scope on J21 pin 7.
would be a good
example.
Very high peak
current and high
delivered energy.
5.3.10
Shorted inductor,
Al-Ll.
Low Voltage Power Supply (A12)
SYMPTOM
SUSPECT AREA
Unit is dead on
Battery
battery power.
Battery dead or not
on turn-on.
in unit.
LCD, self test does
not work, or unit
Blown fuses
will operate but
will not charge.
A2-F1
All-Fl
Vertical jitter,
Replace battery pack
or use Power Base.
Unit does not beep
LED's
CHECKS
-12 volt supply
offset motion of
Check fuse A2-F1.
All-Fl
Remove loads.
Remove
the recorder board,
recorder cable, the
deflection board;
heart rate digits,
distortion of
recorder trace.
troubleshoot the -12 and
-15 volt supplies.
Modulation of the
+/-15 volts
trace edges. Heart
rate digits are
deformed, trace
Remove loads; as above.
Check +/-15 volt supplies.
shrinks.
Trace shrinks and
moves to the center,
Edges of trace fold
inward. Fuzzy, out-
of-focus, jittery
trace.
Modulation
up and down.
5-52
+5 volts
Check the 5 volt output.
If unregulated, remove all
PC boards.
Check the drive
and power switch, Q3.
/^l
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Note: If the 5 volt supply is not regulated, the
rest of the supplies will not be in regulation.
The 5 volt supply must be within the range of 5.0
to 5.2 volts, with the PC boards in place. The
5 volt supply can be as high as 5.35 volts when no
other boards are in place.
The following symptoms assume that the 5 volt supply
is operating normally.
No CRT trace
5 kV supply
R12
Brightness varies,
5 kV clamp
CR4, 8, 15, VR2 thru VR6.
Spikes on CRT trace.
5 kV supply
Tl H.V. secondary. H.V.
multiplier failure.
System dead
L.V. supplies
Fuse A2-F1 on mother board
trace width varies.
Trace length varies.
(A2).
Verify +12 volts
at TP2.
^
Note: The following symptoms assume all power
supply outputs are very low but are not all zero.
System dead
A12-
Connect oscilloscope to
Ul Pin 11 with power on.
If scope indicates DC
offset +12 volts or zero
volts or 30% duty cycle.
Replace Ul.
Q3
Remove Q3 and test Ul, as
above. If 60% duty cycle,
Ul is O.K., test Q3.
Figure 5-31).
(See
Connect voltmeter to Ul
Pin 16.
If not 4.85 to
5.05 volts, replace Ul.
Ql, Q2
Check TPl.
If 60% duty
cycle, Ql and Q2 O.K.
(See Figure 5-31).
Ul Pin 2
Must read approx 2.5 volts
(See Figure 5-32).
Ul Pin 3
50 mS spikes
5-53
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
786 70A-1
Ul Pin 7
3 volts, 60 uS
sawtooth. (See Figure 5-33)
5 V/Div.
A12-U1 Pin 14
Figure 5-31
20pS/Div.
Ul
Pin 10
Ul Pin 16
Less than 0.6 volts
4.85 to 5.05 volts
If not, replace Ul.
Examine the board for
overheated parts. If any
of the inductors, L2, L3
or L4 exhibit signs of
overheating, the problem
lies somewhere else in the
unit.
If the 5 volt supply is out
of tolerance, the 15 volt and
H.V. supplies will be out of
tolerance in the same
direction. However, if one
of the other supplies is
overloaded, it does not
necessarily mean the remaining
supplies will be out of
tolerance.
Turn the adjustment pots
counterclockwise to increase
the voltage.
Out of focus trace
+200V
Rectifiers CR8, CR4, zeners
VR2, VR3, VR6.
Check for long component
leads on bottom of board
shorting to circuit board
shield.
5-54
SECTION V- TROUBLESHOOTING
Models 78670A/78671A
78670A-1
Power Suppy Output Voltage
+5V
+15
-15
+12R
Min.
Max.
5.05
14.50
-14.50
11.50
5.15
15.50
-15.50
12.50
+12 (adjust)
-12V
+200
11.96
12.04
-11.50
+180
-12.50
+210
+5 kV (use 1000 megohm probe.
read 4.2 kV +/-200 V).
Should
Pulse Width Modulator (A12-U1)
5.3.10.1
NORMAL OPERATING VOLTAGE
PIN
Approximately 2.5 volts DC
1
4
Less than 200 mV average
7
Sawtooth 3 volt p-p approx 60 uS
period
9
TP3 (see Figure 5-16)
11-14
Duty cycle controlled rectangular wave (see Figure 5-31)
12-13
Supply voltage
15
Supply voltage
16
+5 volts ref. 4.85 to 5.05
If supply voltage is normal and pin 16 is zero, replace
Ul.
If DC out of supply is very low, check to see if both PWM
output transistors are producing an output.
Pins 11 and 14.
Check low battery detector
PIN
NORMAL OPERATING VOLTAGES
2
+4.46 Volts
3
Greater than 4.46 volts
6
Greater than 4.46 volts
7
Supply voltage
Base Q4
0.6 volts
Collector Q4 Vee sat. less than 0.5 volts.
5-55
SECTION V- TROUBLESHOOTING
Models 78670A/7867IA
786 70A-1
Figure 5-32
5 V/Div.
MA12-TP-1
20uS/Div.
. X.
Figure 5-33
;•'"•
I
2 V/Div.
i
-
f-
I
A12-U1 Pin 7
H
•• -'
,;„\
.M.,.|,M..
,Hr"
•
.-
• +1
<
20pS Dh
.
; .
.
i
1 V/Div.
Figure 5-34
... } j
1
A12-TP-3
-r
"
""j
i
h ••
+
-•
-;-
+
MM
•
• + -| - ^
|
1 I I ;_
20pS, Div.
Figure 5-35
20V/Div.
A12-TP-5
20pS/Div.
Figure 5-36
A 12-T1 Pin 4 Flyback Transformer Secondary
200V/Div.
WidS/Div.
5-56
SECTION VI - REPLACEABLE PARTS
Models 78670A/7867IA
78670-1
REFERENCE DESIGNATORS
A
« assembly
B
BT
=
motor
= battery
= capacitor
F
FL
= fuse
= filter
Q
-
transistor
R
=
resistor
HR
= heater
RT
= thermistor
w
= cable
= jack
= relay
S
= switch
X
= 60cket,
T
= transformer
=
inductor
= terminal board
XF
= fuseholder
meter
TB
TC
TP
= thermocouple
= test point
Y
Z
= crystal
CP
CR
= coupler
= diode
J
K
L
DL
= delay line
M
=
DS
= device signaling (lamp)
E
= miscellaneous elect romc part
MP
P
= mechanical part
= Plug
C
V
= vacuum tube
photocell, etc
XDS
= lampholder
= network
ABBREVIATIONS
.9
A
= amperes
fit hd
=
fillister head
ACC
" accessories
flm
=
film
NC
nano (10 )
normally closed
AFC
= automatic frequency control
FR
fwd
fxd
=
=
=
front
forward
fixed
Ne
neon
NETWRK
Ni PI
NO
NPN
NPO
network
scon
nickel plate
normally open
negative positive negative
Se
Al
= aluminum
AMP
= amplifier
as ord
= as ordered
Be Cu
BFO
= beryllium copper
= beat frequency oscillator
bh
= binder head
bp
brs
c/s
G c/s
= gigacycles per second
Ge
GEN
(see G Hz)
= germanium
= generator
= bandpass
G Hz
= gigacycles per second
-
gl
grd
= glass
= ground(ed)
h
hex
Hg
riz
=
=
=
=
brass
= cycles/second (see Hz)
CALIB = calibration
ccw
= counterclockwise
henry (ics)
hexagonal
mercury
cycle per second
silicon
not separately replaceable
obd
order by description
sil
si
SPDT
single-pole double-
od
outside diameter
oval head
oxide
spl
special
SPST
single-pole single-
pc
printed circuit board
sst
stainless steel
PEMS
circular press fitted nut
SWTCH
switch
ov hd
= channel
cmo
= cabinet mount only
impg
= impregnated
coef
= coefficient
PF
picofarad (10"'2 farads)
incd
= incandescent
PH
com
=
= composition
= insulation(ed)
= inches per second
ph brz
comp
ins
ips
phone
phosphor bronze
Phillips head
= kilo
s
k. K
= clockwise
Kc. k c/s = kilocycles (see k Hz)
dB
connector
= decibel
(1000)
KEPS
= hex rut with lockwasher
washer
sequential
Si
ch
= cathode-ray tube
machine screw with
SEQ
= cadmium plate
CRT
section(s)
SEMS
(zero temperature
= ceramic
conn
sect
coefficient)
cd pi
cw
rotary
slow-blow
semiconductor
selenium
negative positive zero
cer
common
rot
s-b
silver
slide
throw
throw
Phlhd
piv
pk
peak inverse voltage
PP
PREAMP
peak
panel
positive negative positive
polystyrene
porcelain
positionfs)
potentiometer
peak-to-peak
preamplifier
prcc
precision
PNL
PNP
Ta
tantalum
td
time delay
Ti
titanium
tog
toggle
tol
tolerance
trim.
trimmer
twt
traveling wave tube
k Hz
= kilocycles/second
dep C
= deposited carbon
DISP
DPDT
= display
= double-pole double-throw
lin
= linear taper
DOS
Ikwash
= lockwasher
DPST
= double-pole single-throw
pot
log
= logarithmic taper
lp fit
= low-pass filter
m
= nulli (lO"3)
V
volt(s)
mA
= milliamperes
(temperature coeffi
vac
vacuum
result in instrument opera
cient, long term
Vacw
mam
=
volt(s) alternating
ting within specifications;
M
= mcRa (106)
stability, and/or
tubes and transistors selected
M c/s
= megacycles (see M Hz)
for best performance will be
met flm
mfr
= metal film
= manufacturer
= millihenry
- megacycles/second
reel
recorder
rectifier
ElA
= tubes or transistors meeting
Electronic Industries Associ
ation standards will normally
supplied if ordered by stock
numbers
poly
por
milliammeter
Pt
tolerance)
point
»jor U
HA
(iF
*iV
micro (10* )
microamperes
microfarads
microvolts
current working
var
variable
Vdcw
volt(s) direct current
W
watt (s)
with
working
rec
elect
= electrolytic
mH
M Hz
rev
encap
- encapsulated
reverse
nnnut
-
miniature
rf
radio frequency
w/
W/O
mom
mtg
mV
mW
my
-
momentary
mounting
millivolt
milliwatt
mvlar -
rh
round head
wiv
rmo
rack mount only
reverse working
voltage
rms
root-mean-square
WW
wi rewound
F
= farad(s)
fet
fh
- field effect transistor
^ flat head
FIG
t
fli:ure
t
-
/*3"^J\
without
ohm
UXiponl de Nemours)
cclrie Accounting Machines (KAM) capitalize all abbreviations
/^k
6-4
SECTION VI•- REPLACEABLEPARTS
Models 78670A/78671A
78670-1
Table 6-1.
MFR
NO.
0 0 03J
0 0853
01121
01281
01295
0192B
02111
03508
03888
04222
04713
07263
12617
13606
17856
19701
20932
24546
25088
27014
27777
28480
32293
34649
56289
71590
72136
7V5Q42
75915
84411
MANUFACTURER
Manufacture's
Code.
NAME
NIPPON ELECTRIC CO
SANGAMO ELEC CO S CAROLINA DIV
ALLEN-BRADLEY
CO
TRW INC SEMICONDUCTOR DIV
TEXAS INSTR INC SEMICOND CMPNT
DIV
RCA CORP SOLID STATE DIV
SPECTROL ELECTRONICS CORP
GE CO SEMICONDUCTOR PROD DEPT
KDI PYROFILM CORP
AVX CERAMICS CORP
MOTOROLA SEMICONDUCTOR PRODUCTS
FAIRCHILD SEMICONDUCTOR DIV
HAMLIN INC
SPRAGUE ELECT CO SEMICONDUCTOR DIV
SILICONIX INC
MEPCO/ELECTRA CORP
EMCON DIV ITU
CORNING GLASS WORKS (BRADFORD)
SIEMENS
CORP
NATIONAL SEMICONDUCTOR CORP
VARO SEMICONDUCTOR INC
HEWLETT-PACKARD CO CORPORATE HQ
INTERSIL INC
INTEL CORP
SPRAGUE ELECTRIC CO
CENTRALAB ELEK DIV GLOBE-UNION INC
ELECTRO MOTIVE CORP SUB IEC
TRW INC PHILADELPHIA DIV
LITTELFUSE
INC
TRW CAPACITOR
DIV
ZIP
CODE
ADDRESS
PICKENS
MILWAUKEE
LAWNDALE
DALLAS
SQMERVILLE
CITY OF IND
SYRACUSE
WHIPPANY
MYRTLE BEACH
PHOENIX
MOUNTAIN VIEW
LAKE MILLS
CONCORD
SANTA CLARA
MINERAL WELLS
SAN DIEGO
BRADFORD
ISELIN
SANTA CLARA
GARLAND
PALO ALTO
CUPERTINO
MOUNTAIN VIEW
NORTH ADAMS
SC
WI
CA
TX
29671
53204
90260
75222
NJ
08876
CA
NY
NJ
SC
A2
CA
WI
91745
13201
07981
29577
85062
94042
53551
NH
03301
CA
TX
CA
PA
95054
NJ
CA
TX
CA
CA
CA
MILWAUKEE
WILLIMANTIC
PHILADELPHIA
DES PLAINES
MA
WI
CT
PA
IL
OGALLALA
NE
76067
92129
16701
08830
95051
75040
94304
95014
95051
01247
50501
06226
19108
60016
69153
6-3
SECTION VI - REPLA CEABLE PAR TS
Models 78670A/78671A
78670-1
6.3
ORDERING INFORMATION
NOTE: Occasionally, electronic items in the replacement parts list will be found to
carry standard
commercial identification numbers but
which also are
indicated as
being manufactured by HP. These components have been selected to meet specific
operational criteria.
The use of these components purchased through normal
commercial channels may result in degradation of the operation performance or
reliability of the unit.
To order a replacement part, address order or inquiry to the local Hewlett-Packard
Sales/Service Office (see list of addresses at the rear of this manual) and supply
the HP part number of the item from the listing.
To order a part not listed in a table, provide the following information:
1.
Model number of the instrument.
2.
Complete serial number of the instrument.
3.
Description of the part including function and location.
To order a part from a manufacturer other than Hewlett-Packard Company, provide the
complete part description and the manufacturer's part number from the listing.
Manufacturer's codes are listed in Table 6-1.
6-2
SECTION VI - REPLA CEABLE PAR TS
Models 78670A/78671A
78670-1
SECTION VI
REPLACEABLE PARTS
^^s
6.1
INTRODUCTION
This section of the service manual includes schematic diagrams and identifies major
assemblies, subassemblies, and components of both defibrillators to aid in ordering
replacement parts. Each entry in these tables includes the reference designation,
HP part number, check digit, quantity used within the referenced assembly, a brief
description of the part, the NEC code of the manufacturer of the part and the part
number assigned by the manufacturer. Wherever possible, parts lists for the
assemblies are printed on the same page as the schematic diagram and component
location drawing or on immediate adjacent pages.
6.2
REFERENCE DESIGNATIONS
The parts listings use an alphabetical-numerical (alpha-numeric) method of listing
the end item, assemblies, subassemblies and circuit components. These items are
defined as follows:
1. An END ITEM is the instrument with all the supplied accessories,
is made up of assemblies to aid in the location of parts.
f^
The END ITEM
2. Each assembly and subassembly is assigned an "A" number (Al, A2, A3, etc),
Assemblies and subassemblies that can be purchased have part numbers in the part
number column of the table; those that cannot be purchased do not have part numbers
in the columns.
3. Components within the assembly and subassembly circuits are assigned circuit
reference designators (CI capacitor, Rl resistor, etc). These parts are prefaced
by the assembly number (A1C1, A2C2, A1R1, A2R2, etc), to indicate the assembly on
which the part is located.
An
example of
the alpha-numeric
numbering
method used
to identify
assemblies,
subassemblies and circuit components is shown below:
R
ASSEMBLY NO.
COMPONENT ALPHA
DESIGNATION
COMPONENT NUMERIC
DESIGNATION
The complete reference designations is read as the first resistor (Rl) of the first
assembly (Al).
6-1
SECTION VII-ACCESSORIES
Models 78670A/78671A
786 70A-1
SECTION VII
ACCESSORIES
Figure 7-1. Quick-Mount Power Base.
7.1
78668A Quick-Mount Power Base
This accessory
allows the 78670A and 78671A defibrillators
power line.
All power supplies to the
installed on the power base.
defibrillator, are
to operate from
connected when
the AC
it is
The power base supplies:
1.
Regulated 12.5 volts DC for all monitor and control functions.
2.
Unregulated V-Raw DC for defibrillator charging.
3.
Current - limited DC for charging the defibrillator battery.
In
case of
loss of
power line
voltage,
a fast
shutdown circuit
automatically
transfers the defibrillator power lines back to its internal battery.
7.1.1
Theory of Operation - AC Circuits (Figure 7-4)
The AC input circuit is the customary dual winding 115/230 VAC configuration,
selected by SI, protected by CB1 and CB2. C13 reduces the effects of fast rise
power line transient spikes. A thermal fuse is part of the Tl secondary winding.
7.1.2
Regulated Voltage Circuit
DC for this circuit is from the bridge rectifier (CRll) and filter capacitor (Cll),
with Rl
as a bleeder
resistor.
Ull is
a 5
amp, adjustable voltage
series pass
regulator I.C. R4 and R5 set the output voltage. CR3 is a protection diode and
C2, C3, C15 and 016 are stability bypass capacitors. Fast shutdown, to about 1.3
volts DC is accomplished by pulling Ull ADJUST terminal to ground.
7-1
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
/^|k
7.1.3
Raw Voltage and Battery Charge Circuit
DC for these circuits is from CR12, C12 and RIO. Voltage is supplied directly to
the high-current, defibrillator capacitor charge circuits on the defibrillator H.V.
board (All).
This DC source also powers the current regulator Ul, with R9 giving a nominal 0.20
A battery charge current.
This supply is connected to the battery when the
defibrillator is on the AC-connected Power Base. CR4 and CR5 are protection
diodes. Fast shutdown to about 2.3 volts DC is accomplished by pulling Ul ADJUST
terminal to ground.
7.1.4
Low Line Voltage Circuit
Both Ul and Ull regulators can be shutdown by pulling their ADJUST terminals to
ground. This allows the battery relay, in the defibrillator, to switch to battery
operation in less than 100 msec, instead of waiting for the slower discharge of the
10,000 uF filter capacitors, C12 and Cll.
CRl, CR2 and CI form a full wave rectifier circuit for the transformer output. R8
and R7 form a divider/bleeder. If the 115 VAC input remains over about 50 VAC, Ql
conducts, keeping Q3 and Q2 nonconducting. A further drop to about 40 VAC switches
both Q3 and Q2 into saturation, clamping the voltage adjust terminals of the two
regulators to ground.
7.1.4.1
Disassembly
1.
Remove the defibrillator from the power base.
Remove the power line cord.
2.
Place the power base upside down.
3.
Lift the electronics section from the plastic base.
Remove the 6 screws indicated in Figure 7-2.
4. The circuit board may be removed with capacitors Cll and C12 attached. Remove
the two hex nuts just in front of the finned heat sink and loosen the capacitor
clamps.(Figure 7-3).
Note: If the capacitors Cll or C12 are removed, be sure
the terminal screws are tight when the unit is assembled.
WARNING
The two filter capacitors, Cll and C12, store enough energy
to vaporize the tip of a screwdriver.
Allow at least 3
minutes for the capacitors to discharge before shorting the
capacitors or removing circuit components.
7-2
")
SECTION VII - A CCESSORIES
Models 78670A/78671A
786 70A-1
Figure 7-2. Quick-Mount Power Base, (Bottom View).
Figure 7-3. Quick-Mount Power Base Inner Circuitry.
7.1.5
Troubleshooting Power Base
SYMPTOM
Circuit breakers open
(CB1-CB2)
SUSPECT AREA
Cll, 012 short
Ull, 015, 016 short
CHECKS
Disconnect and make
resistance check.
Pull P55.
Check for
shorts including
to chasis.
7-3
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
Transformer Tl short
Pull secondary
connectors.
Reset
circuit breakers.
Connect to AC. Normal
secondary voltage
approx 20 volts.
Low output voltage
Line voltage selector
Switch in 230 volt
switch
position for 115
volt line.
No output on all
supplies.
SI, CB1, CB2
(Circuit
breakers may or may
Thermal fuse in Tl open
not be open)
Measure voltage
through transformer.
Check Tl winding
resistance. Primary
approx 10 ohms each.
Secondary less than
1 ohn. disconnect
secondary v/irinq
hoFor^ ^akino
resistance check.
V-Raw less than
CR12, C12
15 volts (no load)
V BAT less than
12 volts
Check voltage at J55
Pin 2. Check wave
form V-Raw under
load.
Defective or discharged
battery.
Check battery
Q3 ON
Check low line.
Shut down circuit
voltage.
R9, Rll, CR4, CR5
Check for shorted
diodes or open
resistors.
CI
Check for short.
Ul
tab to heat sink.
Low line voltage shut
Check AC on/AC off,
DC voltages in
Defective or shorted
Defib battery relay
All-Kl, does not
immediately transfer
to battery at power
down circuit
circuit.
loss.
Defib BATTERY LED does
not immediately turn-off
with power line voltage
loss.
7-4
Same as above
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
Power Base Trouble Shooting
These measurements made with 115V AC 60Hz input.
Test Point
Voltage
Condition
T1 Secondary
Approximate 20VAC
No Load
Across C11 and C12
Approximate 28VDC
No Load
Voltage across C2
(U11 Output, V Reg)
12.5V Nominal
No Load
J54 Pin 4 to Pin 1
Approximate 28VDC
Approximate 14 to 16VDC
with battery load
Approximate 28VDC
Approximate 26VDC
Monitor Only
(battery charger output)
J54 Pin 3 to Pin 1
(V Raw)
No
Load
No Load
f*
Fast turn-off circuit activated by pulling the cord. All measurements referenced to on board ground
(negative terminal of C11 and C12). Nominal voltages are listed and may vary slightly.
ON
Fast Turn-Off
11.5V
0.12V
C1 Positive terminal
11.3V
0.12V
U11 Adj Terminal
28V
.02V
U1 Adj Terminal
.04V
0.7V
Q1 Collector
.04V
0.7V
Q2 Base
.04V
0.7V
Q3 Base
#^v
7-5
SECTION VH-ACCESSORIES
Models 78670A/78671A
78670A-1
/^
NOTES
f^\
r%
7-6
SECTION VII - ACCESSORIES
Models 78670A/78671A
786 70A-1
^
Figure 7-5. 78669A Battery Charger.
7.2
7.2.1
BATTERY CHARGER 78669A
Description
This instrument charges batteries for the Model 78670A or 78671A Defibrillators.
It will charge one or two batteries at a time. No power switch is included in this
instrument. Charging begins whenever a battery is inserted.
7.2.2
Charging
Batteries are inserted into the cavities on top of the charger. The plugs in the
charger cavity contact the jacks in the battery housing and charging begins. The
batteries are inserted with the tab at the rear of the battery
toward the
center of the charger. If a battery is inserted backwards, no contact takes place.
7.2.3
Indicator Lamps (See Figure 7-5).
The green lamp labelled "POWER ON" in the center of the panel
cord is plugged in, indicating the instrument has A.C. power.
On each side of the front panel are 3 indicators
battery charging cycle.
A green CHARGING indicator
plugged in, to indicate that the charger is supplying
lamp will glow as long as the battery is plugged into
glows when the line
that give the status of the
lamp glows when a battery is
current to the battery. This
the charger.
7-9
SECTION VII - A CCESSORIES
Models 78670A/78671A
78670A-l
The 2 remaining yellow lamps indicate the time the battery has been charging.
The
first lamp lights at approximately 8 hours after charging begins. At the end of a
second 8 hour period, the 8 hour lamp is extinguished and another lamp lights
indicating 16 hours. Since 16 hours is considered the normal recharge time, the 16
hour lamp can be considered a full charge indicator. The 16 hour lamp will remain
on until the battery is removed or power is interrupted.
The charge time indicators are independent for the two batteries and timing begins
for a particular battery when it is placed in the charger.
When a battery is
removed, the timing for that section of the charger is automatically reset to zero,
regardless of the charging time on the battery.
The battery may be left on continuous charge, without damage. However, batteries
should be deep discharged at 3 month intervals to maintain their capacity. See
Section III for details.
A rear panel mounted switch allows selection of power line voltage 115-230 volts.
7.2.4
Battery Charger Theory of Operation
(Refer to Schematic Diagram, Figure 7-13).
The power transformer Tl, has dual primary windings which are switched in series
for 230 volt operation or parallel for use on 115 volts. Each winding is fused to
comply with UL and European requirements.
A full wave bridge rectifier, CRl thru CR4, rectifies the low voltage of the
transformer secondary to provide DC for the control circuits and for battery
charging.
Since the battery charging and indicator circuits are identical for each channel,
only one will be described. Only the power supply and timing oscillator are common
to both channels.
7.2.5
Current Source
Nickel-cadmium batteries require a constant current
for charging.
as a current source. The current is determined by Rl.
limit when the voltage drop across Rl equals 1.25 volts.
Ul is connected
Ul will go
into current
I charge = 1.25/R1 = 1.25/6.2 = .202 amperes
When the current drawn through Rl exceeds approximately 160 mA, Ql conducts current
to light DS-1, indicating current
is being drawn by the battery.
Under
no load
conditions, the charger output is approximately 30 volts DC.
7.2.6
Tininn Circuit Voltage Regulator
When Ql conducts current, it furnishes power to the 12 volt regulator U4. This
regulator provides a regulated voltage to the C-M0S timing circuits and the 8 and
16 hour LED indicators.
7-10
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
7.2.7
Timing Oscillator
U7 contains an R-C oscillator and a divide by 1024 circuit.
This circuit operates
when a battery is plugged into the charger, with the +12 volts applied through CR7
or CR8. C3 and R4 are the timing elements. The oscillator runs at a cycle period
of about 27.8 mS at U7 Pin 1. The output of U7 is available at TP-1 and has a one
cycle period of approximately 28.5 seconds.
See timing diagram Figure 7-6,
and schematic.
4541
r
4040
U7
U2
4011
osc
PIN
-&>
-H024
—T
10
+ 2048
-r2
I
15
L
j^\
» 27.8mS
»
28.5 Sec
*
8.1 HR
«•
16.2 HR
Figure 7-6. Timing Diagram.
7.2.8
Clock Gate
U6B is a nand gate which passes the 28.5 second clock signal when enabled by +12
volts on Pin 6. At the end of 16 hours, Q2 collector is pulled to ground which
removes the clock signal from U2.
7.2.9
Divide By 2048 and Divide By 4096 Counters
U2 is a 12 bit binary counter with divide by 2048 and divide by 4096 outputs
selected for 8 and 16 hours. After approximately 8.1 hours, the divide by 2048
output goes
high, turning on Q3 which lights the 8 hour LED indicator,
DS3.
At
16.2 hours, the divide 2048 output goes low and the 4096 output goes high with Q2
lighting the 16 hour LED, DS2, and removing the clock signal so that U2 will hold
its count.
7.2.10
Counter Reset Gate
When the battery is removed, the +12 volts is removed from the input to U6A. This
causes
the gate
output
to go
high.
Resetting the counter,
U2,
to zero and
extinguishes the 8 or 16 hour LED if it is on.
7-11
SECTION VII - ACCESSORIES
Models 78670A/786 71A
786 70A-1
7.2.11
There
Maintenance
are no
adjustments
in this
instrument.
Therefore,
the
only reason
for
disassembly will be for repair.
7.2.12
Disassembly
The molded plastic case consists of an upper and lower section.
Both case sections
are removed for .service.
1.
Top cover removal.
See Figure 7-7.
(a) Unscrew the four banana plugs located in the battery cavities. These
plugs have a metric hex nut section but can be removed with a 1/4 inch nut driver.
(b) Lift the rear of the top cover about 1/2 inch, just above the heat sink.
Slip your fingers under the edge of the front panel and spring it forward to clear
the LED's.
Lift off the cover.
Figure 7-7. Top Cover Removal.
2a.
Bottom cover removal.
See Figure 7-8.
(a) Lay the battery charger on its
top.
Use a small posidrive screwdriver to
remove the four rubber feet.
2b.
Lift off the bottom cover.
-
7-72
\
SECTION VII - A CCESSORIES
Models 78670A/78671A
7 86 70A-1
Figure 7-8. Bottom Cover Removal.
3.
Circuit board removal.
NOTE: All nuts used in the structure are
captive PEM nuts except the two used
on the current regulators, Ul and U5.
(a) Remove the finned
heat radiator by removing the four screws shown
in
Figure 7-9.
Figure 7-9. Removing Heat Radiator.
(b) Place the unit on its back where the heat sink was removed.
(c) See Figure 7-10.
Remove the two screws, A, to loosen the LED board,
remains attached to the main circuit board by a short flat jumper cable.
It
(d) Unscrew the two hex posts, B.
7-13
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
Figure 7-10. Battery Charger With Top Cover Removed.
(e) Refer to Figure 7-11.
bottom sheet metal
is now free.
Remove the 4 screws shown in the illustration.
The
transformer remains attached to
The
the circuit
board.
"
Figure 7-11. Battery Charger With Bottom Cover Removed.
7-14
SECTION VII• ACCESSORIES
Models 78670A/78671A
78670A-1
4. The power cord connector bracket remains attached to the circuit board. See
Figure 7-12. The transformer is secured to the main board by four screws and the
electrical
5.
contacts are soldered into the board.
Assembly is done in the reverse order.
NOTE: When replacing
the top cover, spring
the front panel forward
to clear
the LED's.
'-' -11 • •
Figure 7-12. Battery Charger Circuit Board.
7.2.13
Troubleshooting Battery Charger
7.2.13.1
Equipment Required:
DVM or VOM
SYMPTOM
CHECK
Unit plugged into AC power.
Power
LED does not light
Charging LED does not light when
1.
Line AC outlet
2.
3.
Defective power cord.
Line voltage selector
switch in wrong position
4.
Blown fuse
5.
Defective transformer, Tl
6.
Defective LED
1.
Open battery (no load on
charger)
battery is plugged in.
NOTE:
2.
Ul or U5
3.
Ql or Q4
4.
5.
Rl or Rll
U4 or U8
A battery load may be simulated by connecting
a 70-75 ohm resistor in place of the battery.
dissipation is approximately 3 watts.
Power
7-15
SECTION VII - A CCESSORIES
Models 78670A/78671A
78670A-1
The following symptoms concern the 8 and 16 hour LED's.
A battery or resistor must
be connected across the charger terminals to power the charge time indicator
circuits. These tests assume the battery has been on charge for at least 16 hours.
The battery should be warm to the touch if charging is taking place.
SYMPTOM
CHECK
8 and 16 hour LED's do not
Connect DC voltmeter to TPl.
light on either side. Batteries
warm after 16 hours charge. Charging
LED's light.
Voltage should switch between
zero and Vcc (approximately
12 volts) at about 14 second
intervals. If this switching
action does not occur, check
Vcc.
8 and 16 hour LED does not operate
on one side only.
U7 defective.
U4 or U8
Battery is warm.
Charging LED lights.
U2 or U3
The 8 and 16 hour LED's may be checked by connecting a battery
or resistor load to the charger and grounding the collector of
the transistor driver for the LED under test.
DO NOT GROUND
the LED cathode.
To check the LED driver transistor, connect a 22K resistor
between Vcc and the base of the transistor.
The LED should
light.
8 and 16 hour LED's do not light
on one side only. Charging LED
does not light on that side. Battery
Ql or Q4
is warm.
8 and 16 hour LED's do not light on
one side only. Charging LED does not
light. Battery is cold.
See Figure 7-13.
7-16
Ul or U5
/*^\
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
7.3
RECHARGEABLE NICKEL CADMIUM BATTERY - Bl
Many nickel
cadmium batteries
are needlessly replaced
each year
because service
personnel did not understand their characteristics. Most storage batteries require
a certain amount of maintenance, and the nickel cadmium battery is no exception.
However,
their maintenance
requirements are
quite different
from an
automobile
battery, for example.
7.3.1
General Description
The battery (Bl) used in the portable defibrillator is a 10-cell, 2.0 AH sealed
nickel cadmium type.
It is charged with a constant current source of 200 mA and
can sustain overcharging indefinitely at this rate. The internal construction and
chemistry of the battery is such that oxygen generated during overcharging rapidly
diffuses through the cell and recombines at the negative plate.
Consequently,
there is no excessive pressure build-up in the cells and the excess energy is
converted to heat; a fully-charged battery will be warm to the touch when kept on
overcharge. Since no detrimental effects occur because of overcharging, the unit
should be kept charging whenever practical.
7.3.2
^s-
Charge Retention
The nickel cadmium battery has a relatively high self discharge rate, when compared
to other types of batteries. Charge retention depends on the storage temperature
and the age and condition of the battery.
The self discharge rates for new
batteries are listed below:
Temperature
7.3.3
Self Discharge/Month
0°C (32°F)
10%
20°C (68°F)
30%
40°C (104°F)
70%
Charging
The heat generated during normal overcharge however, necessitates that the battery
not be charged when the ambient temperature exceeds 45°C. The battery should not
be charged when the ambient temperature is below 5°C. Charging below this
temperature may cause build-up of excessive pressure, with a resultant venting of
the cells.
Venting will cause loss of electrolyte and gradual loss of battery
capacity.
7.3.4
Voltage Depression (Memory)
Nickel cadmium batteries that are left on continuous charge, for long periods of
time, suffer from a voltage depression pheomenon. The terminal voltage, under
load, will be about 1 volt less than that of a battery in good operating condition.
The apparent effect is reduced battery capacity, sometimes referred to as memory.
7-19
SECTION VII - ACCESSORIES
Models 78670A/78671A
78670A-1
Under conditions of long continuous charge, the crystals of active material within
the plates of the cells, begin to increase in size. As the crystals grow larger,
the surface area of active material in contact with the electrolyte decreases. The
effect
is an increase in internal resistance of the battery.
exhibited as premature flashing of the low battery warning light.
7.3.5
This
will
be
Reconditioning Charge/Discharge Cycle
The effects
of voltage
depression can
be eliminated
by exercising
the battery.
This can be accomplished by the following procedure:
1.
Charge battery for 16 hours.
2.
Remove the defibrillator from the Quick-Mount Power Base.
3.
Turn ENERGY SELECT switch to MONITOR ON position.
4.
Allow the battery to discharge until the LOW BATTERY light flashes.
DO NOT LEAVE THE UNIT ON FOR A LONG
cell reversal may occur.
PERIOD AFTER THE BATTERY LOW LIGHT FLASHES, or
An alternate method is to connect the battery to a test load (HP 78620-60860).
Connect a voltmeter to the test load and monitor the discharge.
Discharge the
battery until the voltage falls below 10 volts. DO NOT ALLOW THE VOLTAGE TO FALL
BELOW 9.0 VOLTS, or cell reversal may occur.
Use Model 78660-67800 adapters to
connect the battery to the test load.
7.3.6
Cell Reversal
Cell reversal, due to deep discharge, can occur whenever the battery voltage drops
low enough (i.e., about 9 volts) to cause one of the cells to reach zero volts.
The current flowing through the battery pack will then tend to reverse-charge this
(weakest) cell. Reverse charging generates hydrogen and oxygen which will cause a
rise in internal pressure and possible subsequent venting if the pressure increases
sufficiently.
The cells have resealable vents, and only a small amount of
electrolyte escapes during venting. However, after 10 or more venting incidents,
the affected cell will begin to lose capacity and reach reversal earlier.
To minimize this possibility, cells are closely matched in capacity during
manufacturing. This ensures that the loss of the weakest cell will be followed
shortly by the collapse of the remaining cells. Therefore, when the weakest cell
is fully discharged, the remaining cells have so little capacity that current flow
is not enough to seriously reverse-charge the weakest cell. This matching of cell
capacity makes it imperative that individual cells never be replaced. In the event
of a weak battery, the entire battery pack must be replaced.
As a further
precaution, turn the unit off, or plug in whenever the trace starts to dim or has
disappeared.
7.3.7
Battery Replacement 78660-60401
^
1
As a battery ages, its capacity will be reduced. If the LOW BATTERY warning starts
flashing after only 2 hours of monitoring, and the voltage is not depressed due to
7-20
—
SECTION VII - A CCESSORIES
Models 78670A/78671A
78670A-4
long term continuous overcharging, the battery is showing signs of weakening. A
fully charged battery should be capable of sustaining at least 2-1/2 hours of
monitoring. If the battery is incapable of meeting this minimum, it should be
replaced. However, test the battery before replacing. See Section 3.2.3.7.
7.3.8
Storage of Nickel Cadmium Batteries
If the batteries must be stored, they should be charged about once every three months if stored at nor
mal room temperature. After removal from storage, the battery should bedeep discharged and recharg
ed once or twice to restore its capacity.
7-21
SECTION VIII- OPTIONS
Models 78670A/78671A
78670-3
SECTION VIM
OPTIONS
Reference
Designation
HP Part
Number
C
0
Qty
Description
Mfr
Code
Mfr.Part Number
PERTAINS TO THESE INSTRUMENTS
78670A AND 78671A
A01
78671A (Only)
OPTION A01
0460-1678
0470-0573
1400-1038
1400-1038
9270-0980
DELETE RECORDER
6
+
2
+
7
4+
ADHESIVE TAPE
ADH-LOCTITE 222
FASTENER
FASTENER
RECORDER PAPER
28480
04601678
28480
28480
28480
0470-0573
28480
9270-0980
1400-1038
1400-1038
7
2-
7
3-
5952-6866
2
1-
OPERATING CARD
28480
5952-6866
5952-6868
7866040032
78660-61605
78660-61616
4
1+
1+
28480
28480
1-
OPERATING CARD
FILLER PAD
CBL AY-RECORDER
5952-6868
2
6
9
CBL AY-SPEAKER
28480
28480
78660-61605
1+
1-
FRONT PANEL
FRONT PANEL
PANEL-FILLER
28480
28480
28480
78671-07200
78671-07201
78671-27204
ADH-LOCTITE 222
FASTENER
FASTENER
RECORDER PAPER
28480
28480
28480
28480
0470-0573
28480
28480
5952-6866
28480
28480
78660-40032
28480
28480
28480
28480
78671-07200
78671-07201
78671-27204
6
7
1+
2
H
78660-40032
78660-61616
78671A (OnlyI
A02
OPTION A02
0470-0573
1400-1038
1440-1038
9270-0980
DELETE RECORDER AND HEART RATE
2
+
7
4+
7
2-
7
3-
5952-6866
5952-6868
78660-40032
78660-60200
78660-60210
2
4
1-
7
1-
OPERATING CARD
OPERATING CARD
FILLER PAD
PC AY-RECRDCTRL
PC AY-HEART RATE
78660-61605
78660-61616
78671-07200
78671-07201
6
1-
CBL AY-RECORDER
78671-27204
1+
2
1+
5
1-
9
1+
CBL AY-SPEAKER
6
1-
7
1+
2
1+
FRONT PANEL
FRONT PANEL
PANEL-FILLER
28480
1400-1038
1400-1038
9270-0980
5952-6868
78660-60200
78660-60210
78660-61605
28480
78660-61616
78671-07200
78671-07201
78671-27204
28480
78669A
28480
78668A
28480
14412D
28480
28480
14993A
C01
OPTION C01
78669A
ADD 78669A SPARE BATTERY CHARGER
1+
AUXBATTCHGR
1-
QUICK-MOUNT POWER BASE
C02
OPTION C02
78668A
DELETE 78668A QUICK-MOUNT POWER BASE
C03
78670A (Only)
OPTION C03
14412D
1+
ADD ANT/POST PADDLE
PADDLE ASSY-APEX
C04
C04
78670A (Only)
OPTION C04
ADULT INTERNAL PADDLES
14990B
1+
14993A
1+
HANDLE SET-INTERNAL
ELECTRODE SET-ADULT
1499OB
f^
8-1
SECTION VIII - OPTIONS
Models 78670A/78671A
78670A-4
/^k
Reference
Designation
HP Part
Number
c
D
Description
Qty
Mfr
Code
Mfr Part Number
78670A (Only!
C05
OPTION C05
PEDI INTERNAL PADDLES
14990B
i+
14992A
n
HANDLE SET-INTERNAL
ELECTRODE SET-PEDI
28480
28480
14992A
28480
28480
14990B
14994A
28480
14983A
14990B
78670A (Only)
C06
INFANT INTERNAL PADDLES
OPTION C06
14990B
14994A
1+
HANDLE SET-INTERNAL
1+
ELECTRODE-INTERNAL INFANT
78670A (Only)
C07
OPTION C07
DELETE STANDARD PADDLES
14983A
1-
PADDLE SET-DEFIBRILLATOR
L01
OPTION L01
FRENCH LABELS
7121-0763
7121-2424
7
i-
LABEL-INFO
28480
7121-0763
1
1+
LABEL-INFO
28480
7121-2424
7121-0764
8
1-
28480
28480
28480
28480
28480
7121-1675
2
1+
LABEL-INFO
LABEL-INFO
7121-0765
9
3
1-
LABEL-WARNING
1+
1
i-
LABEL-WARNING
LABEL-WARNING
4
i+
2
1-
5
i+
9
i-
2
u
0
i-
7121-1675
7121-0767
7121-1677
7121-0768
7121-1678
7121-0773
7121-1683
7121-0774
7121-1684
7121-0775
7121-1685
7121-0776
7121-1686
7121-0777
7121-1687
3
1+
1
1-
4
i+
2
5
i-
3
1-
6
1+
0
i-
LABEL-INFO
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-INFO
LABEL-INFO
LABEL-INFO
LABEL-DEFIB CONTROL
28480
28480
28480
28480
28480
28480
28480
6
1+
LABEL-OPERATING INSTRUCTIONS
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
7121-4004
3
2-
LABEL-TWIST PADDLE
28480
78670-84517
9
2+
LABEL-TWIST PADDLE
28480
4
1-
7121-3918
78670-84510
7121-3921
78670-84513
7121-3922
78670-84514
i+
2
i+
5
i-
5
1+
LABEL-INFO
LABEL-APEX PADDLE
6
1-
LABEL-INFO
78670-84512
4
1+
LABEL-STERNUM PADDLE
LABEL-STERNUM PADDLE
7121-3924
8
1-
LABEL-INFO
78670-84515
7
1+
LABEL-CHARGE
7121-4142
4
1-
0
1+
78670-84518
78670-07200
78670-07201
5952-6866
5952-6874
7121-0765
7121-1676
7121-0767
7121-1677
7121-0768
7121-1678
7121-0773
7121-1683
7121-0774
7121 1684
7121-0775
7121-1685
7121-0776
7121-1686
7121-0777
7121-1687
7121-3918
78670-84510
7121-3921
78670-84513
7121-3922
78670-84514
7121-4004
78670-84517
78670A (Only I
L01
7121-3920
8-2
LABEL-WARNING
LABEL-INFO
7121-0764
7121-1675
28480
28480
28480
7121-3920
78670-84512
7121-3924
LABEL-INFO
28480
28480
7121-4142
LABEL-PADDLE CONTACT
28480
78670-84515
78670-84518
78670-07200
78670-07201
5952-6866
5952-6874
5
1-
PANEL-FRONT
28480
6
2
1+
PANEL-FRONT
28480
1-
OPERATORS CARD
28480
2
1+
5
1-
78670-91996
7120-6767
3
1+
OPERATORS CARD
OPERATING GUIDE
OPERATING GUIDE
28480
78670-91998
1
U
LABE L-LATCHE D/UN LACTE D
28480
78670-91998
78670-91996
7120-6767
28480
28480
7121-2503
7
1-
LABEL-CAUTION
28480
7121-2503
7121-2502
6
1+
LABEL-CAUTION
28480
7121-2502
7121-1373
7
1+
LABEL-INFO
28480
7121-1373
SECTION VIII - OPTIONS
Models 78670A/78671A
78670AS
f^\
Reference
Designation
HP Part
Number
C
Description
Qty
0
Mfr
Code
Mfr Part Number
78671A (Only)
LABEL-STERNUM PADDLE
LABEL-STERNUM PADDLE
PANEL-FRONT
PANEL-FRONT
28480
28480
28480
28480
78671-07202
28480
i-
OPERATORS CARD
OPERATORS CARD
OPERATING GUIDE
5952-6868
5952-6875
78671-91998
1+
OPERATING GUIDE
7121-4003
2
i-
78670-84516
8
i+
78671-07200
78671-07202
5952-6868
5952-6875
78671-91998
6
8
i-
4
1-
6
78671-91996
4
7121-0484
9
n
LABEL-INFO
7121-0763
7
1-
LABEL-INFO
1+
3
u
28480
28480
28480
7121-4003
78670-84516
78671-07200
78671-91996
L02
GERMAN LABELS
OPTION L02
7121-2424
1
i+
LABEL-INFO
7121-0764
8
i-
LABEL-INFO
LABEL-INFO
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
7121-1693
4
i+
7121-0765
7121-1694
7121-0767
9
5
i-
1
i-
7121-1695
i+
6
i+
LABEL-WARNING
7121-0768
2
i-
7121-1696
7
1+
7121-0773
9
i-
7121-1701
5
i+
LABEL-INFO
LABEL-INFO
LABEL-WARNING
LABEL-WARNING
28480
28480
28480
28480
28480
7121-0484
28480
7121-0765
28480
7121-1694
7121-0767
28480
28480
28480
28480
28480
28480
7121-0774
0
i-
LABEL-WARNING
28480
7121-1702
6
i+
1
i-
LABEL-INFO
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-INFO
LABEL-INFO
28480
7121-0775
7121-1703
7121-0776
2
i-
7121-1704
8
1+
7121-0777
3
i-
7121-1705
7121-3918
78670-84520
7121-3921
78670-84523
7121-3922
78670-84524
7121-4004
9
i+
0
1-
78670-84527
7
i+
4
i+
5
1-
7
1+
6
8
3
i-
2-
1
2+
i+
LABEL-INFO
LABEL-DEFIB CONTROL
LABEL-INFO
LABEL-APEX PADDLE
LABEL-INFO
LABEL-OPERATING INSTRUCTIONS
LABEL-TWIST PADDLE
LABEL-TWIST PADDLE
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
7121-0763
7121-2424
7121-0764
7121-1693
7121-1695
7121-0768
7121-1696
7121-0773
7121-1701
7121-0774
7121-1702
7121-0775
7121-1703
7121-0776
7121-1704
7121-0777
7121-1705
7121-3918
78670-84520
7121-3921
78670-84523
7121-3922
78670-84524
7121-4004
78670-84527
78670A (Only)
7121-3920
4
78670-84522
7121-3924
6
1+
LABEL-STERNUM PADDLE
LABEL-STERNUM PADDLE
1-
LABEL-INFO
78670-84525
8
9
1+
LABEL-CHARGE
7121-4142
4
1-
LABEL-INFO
78670-84528
78670-07200
2
1+
LABEL-PADDLE CONTACT
5
1-
1-
PANEL-FRONT
8
1+
7
1-
78670-60201
8
1+
PANEL-FRONT
PC ASSY-RECORDER
PC ASSY-RECORDER
5952-6866
5952-6872
78670-91998
2
1-
0
1+
78670-07203
78670-60200
OPERATORS CARD
OPERATORS CARD
OPERATING GUIDE
LABEL-LATCHED/UNLATCHED
LABEL-CAUTION
LABEL-CAUTION
28480
7121-3920
28480
28480
78670-84522
7121-3924
28480
28480
78670-84525
28480
28480
28480
28480
28480
78670-84528
78670-07200
28480
28480
5952-6866
5952-6872
28480
28480
28480
28480
78670-91998
7120-7941
7121-2503
7121-2536
7121-4142
78670-07203
78670-60200
78670-60201
5
1-
7121-2503
7121-2536
5
7
1*
1-
6
1+
7121-4003
2
1-
LABEL-STERNUM PADDLE
28480
7121-4003
78670-84526
78671-O72O0
78671-07204
0
1+
LABEL-STERNUM
78670-84526
5952-6868
5952-6873
78671-91998
28480
28480
28480
28480
0520-0065
1
8+
7120-7941
78671A (Only!
6
1-
0
1+
PANEL-FRONT
4
1-
OPERATORS CARD
1
1+
6
1-
OPERATORS CARD
OPERATING GUIDE
PHMS 2-56 x .25
PANEL-FRONT
28480
28480
28480
78670-07200
78671-07204
5952-6868
5952-6873
78671-91998
0520-0065
8-3
SECTION VIII - OPTIONS
Models 78670A/78671A
78670-3
Reference
Designation
HP Part
Number
C
0
Description
Qty
Mfr
Code
Mfr Part Number
L03
OPTION L03
DUTCH LABELS
7121-02763
7121-2424
7
1-
1
i+
LABEL-INFO
LABEL-INFO
7121-0764
8
i-
LABEL-INFO
7121-2207
8
i+
7121-0765
7121-2208
9
9
i+
7121-0767
1
i-
LABEL-INFO
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
i-
7121-2198
6
i+
LABEL-WARNING
7121-0768
7121-2197
2
1-
LABEL-INFO
5
i+
LABEL-INFO
9
i-
0
i+
0
i-
7
i+
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-INFO
LABEL-INFO
LABEL-INFO
LABEL-DEFIB CONTROL
LABEL-INFO
LABEL-APEX PADDLE
LABEL-INFO
LABEL-OPERATING INSTRUCTIONS
LABEL-TWIST PADDLE
LABEL-TWIST PADDLE
7121-0773
7121-2192
7121-0774
7121-2191
7121-0775
7121-2190
7121-0776
7121-2189
7121-0777
7121-2188
7121-3918
78670-84530
7121-3921
78670-84533
7121-3922
78670-84534
7121-4004
78670-84537
1
i-
6
i+
2
i-
5
1+
3
i-
4
i+
0
i-
6
5
9
6
0
3
i+
2-
3
2+
ii+
i-
i+
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
24840
28480
28480
28480
28480
28480
28480
7121-02763
7121-2424
7121-0764
7121-2207
7121-0765
7121-2208
7121-0767
7121-2198
7121-0768
7121-2197
7121-0773
7121-2192
7121-0774
7121-2191
7121-0775
7121-2190
7121-0776
7121-2189
7121-0777
7121-2188
7121-3918
78670-84530
7121-3921
78670-84533
7121-3922
78670-84534
7121-4004
78670-84537
78670A (Only)
L03
7121-3920
4
1-
78670-84532
7121-3924
8
8
1-
78670-84535
7121-4142
78670-84538
78670-07200
78670-07204
78670-60200
78670-60201
5952-6866
5952-6876
78670-91998
7121-2503
7121-2505
28480
28480
28480
28480
28480
28480
1+
1
1+
4
1-
4
1+
5
1-
9
7
8
2
1+
1-
1+
1-
4
1+
5
1-
7
1-
9
1+
7121-4003
2
1-
78670-84536
78671X)7200
78671-07206
5952-6868
5952-6877
2
6
1+
2
1+
LABEL-STERNUM PADDLE
LABEL-STERNUM PADDLE
LABEL-INFO
LABEL-CHARGE
LABEL-INFO
LABEL-PADDLE CONTACT
PANEL-FRONT
PANEL-FRONT
PC ASSY-RECORDER
PC ASSY-RECORDER
OPERATORS CARD
OPERATORS CARD
OPERATING GUIDE
LA8EL-CAUTION
LABEL-CAUTION
28480
28480
28480
28480
28480
7121-3920
78670-84532
7121-3924
78670-84535
28480
28480
28480
28480
28480
28480
7121-4142
78670-84538
78670-07200
78670-07204
78670-60200
78670-60201
5852-6866
5952-6876
78670-91998
7121-2503
7121-2505
28480
28480
28480
28480
28480
28480
28480
28480
78670-84536
78671-07200
78670-07206
5952-6868
5952-6877
78671-91998
0520-0065
28480
28480
28480
28480
7120-6645
7121-2526
7121-3922
7121-3923
28480
28480
28480
28480
78671A (Only)
78671-91998
0520-0065
1-
4
1-
5
6
1-
1
8+
4
1+
1+
LABEL-STERNUM PADDLE
LABEL-STERNUM PADDLE
PANEL-FRONT
PANEL-FRONT
OPERATORS CARD
OPERATORS CARD
OPERATING GUIOE
PHMS 2-56 x .25
7121-4003
N01
CSA
OPTION N01
7120-6645
8-4
7121-2526
4
1+
7121-3922
6
1-
7121-3923
7
1+
LABEL-CSA
LABEL-INFO
LABEL-OPERATING INSTRUCTIONS
LABEL-OPER. w/FRENCH WARNING
SECTION VIII - OPTIONS
Models 78670A/78671A
78670A-4
Reference
Designation
HP Part
Number
Description
Qty
OPTION N02
VDE/IEC
0590-0565
1251-5964
NUT-HEX DBL-CHAM
CONN-SGL CONT
BINDING POST-SGL
LABEL-VOE ID
1510-0038
7120-7115
7121-0763
7121-2424
5955-7825
78670-00849
14151A
14463A
14481B
14489B
LABEL-INFO
LABEL-INFO
INST SHT-MFR RES
WASHER
CABLE-LEAD SET
CABLE-TRUNK
CABLE-PATIENT
CABLE AY-ECG
Mfr
Code
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
Mfr Part Number
0590-0565
1251-5964
1510-0038
7120-7115
7121-0763
7121-2424
5955-7825
78670-00849
14151A
14463A
14481B
14489B
78668A POWER BASE
OPTION L01
FRENCH LABELS
71210841
7121 1689
71210842
7121 1690
LABEL WARNING
LABEL WARNING
03211
03211
LABEL IDENT
28480
LABELIDENT
28480
78668-84506
LABEL-SELECTOR
28480
71210841
7121 1689
71210842
7121 1690
78668-84506
78668-84507
LABEL-LINE
28480
78668-84507
OPTION L02
GERMAN LABELS
03211
03211
28480
28480
71210841
7121 1707
71210842
7121 1708
03211
03211
28480
28480
71210841
7121 2186
7121 0842
7121-2185
03211
03211
28480
28480
71206645
7121-1841
78668 62700
7866862703
71210841
7121 1707
71210842
7121 1708
LABEL WARNING
LABEL-WARNING
LABELIDENT
LABELIDENT
DUTCH LABELS
71210841
71212186
71210842
71212185
LABE LWARNING
LABEL-WARNING
LABELIDENT
LABELIDENT
OPTION N01
CSA
71206645
7121 1841
7866S 62700
78668*2703
LABEL CSA
LABEL WARNING
TRANSFORMER
OPTION N02
VDE/IEC
05900565
1251 5964
15100038
71207115
7121-2424
59557825
78620 00849
XFMRCSA TESTED
NUT HEX DBL CHAM
28480
CONN SG. CONT
BINDING POST SGL
LABEL VDE ID
LABELINFO
28480
28240
03211
03211
28480
28480
INST SHT-MFR RES
WASHER
OPTION N05
UK CONFIGURATION
0890-0312
1400-0023
14000307
1400-1254
1450-0622
14500623
7124-1964
78668-40001
78668-27100
78668-61604
78668-61605
78668-84502
78668-84503
78668-84504
SHRINK TUBING .250
TIE WRAP
28480
28480
28480
CLIP-WIRE HARNESS
26480
LAMPHOLDER
LAMP-MINIATURE
28480
28480
28480
CLAMP-CABLE
LABEL-MADE USA
CASE
CASE-MODIFIED
CABLE-PILOT LITE
CABLE-PILOT LITE
LABEL-POWER BASE ON
LABEL-115/240V
LABEL 240V
28480
28480
28480
28480
28480
28480
28480
05900565
1251 5964
12510038
7120 7115
7121-2424
5955-7825
78620 00849
0890-0312
1400-0023
1400-0307
1400-1254
1450-0622
1450-0623
7124-1964
78668-40001
78668-27100
78668-61604
78668-61605
78668-84502
78668-84503
78668-84504
100 VOLT OPERATION
71205716
7866862700
7866862701
LABEL 100/200
TRANSFORMER
TRANSFORMER
03211
28480
28480
71205716
78668 62700
7866862701
8-5
SECTION VIII - OPTIONS
Models 78670A/78671A
78670A-4
Reference
Designation
HP Part
Number
Qty
Description
POWER PLUG AUST
CBL-ASSY ASC112
POWER CORD
12513921
81201369
81203493
5001 2043
AUSTRALIAN POWER CORD
OPTION 901
CORD RETAINER
0780705060
PWRCBLB5 1363
POWER CORD
CLAMP PWR CORD
8120 3493
UK POWER CORD
OPTION 900
8120 1351
5001 2043
CBL-ASSY
POWER CORD
CLAMPPWR CORD
CORD RETAINER
81202104
81203493
5001 2043
0780705060
SWISS POWER CORD
OPTION 906
CBLASSY3COND
POWER CORD
CLAMPPWR CORD
CORD RETAINER
81201689
8120 3493
5001 2043
0780705060
EUROPEAN POWER CORD
OPTION 902
CLAMPPWR CORD
CORD RETAINER
0780705060
Mfr
Code
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
28480
Mfr Part Number
8120 1351
81203493
5001 2043
0780705060
12513921
81201369
8120 2393
5001-2043
078070506
8120 1689
8120 3493
5001-2043
07807 05060
81202104
8120 3493
50012043
0780705060
78669A BATTERY CHARGER
LABELINFO
LABELINFO
LABEL WARNING
LABEL-WARNING
LABEL WARNING
LABEL-WARNING
LABEL-WARNING
PANEL-OVERLAY
PANEL-OVERLAY GR
71210772
7121 1700
71210773
7121 1701
7121-1703
7866907200
7866907202
GERMAN LABELS
OPTION L02
LABEL-INFO
LABELINFO
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
LABEL-WARNING
PANEL-OVERLAY
PANEL-OVERLAY FR
71210771
71212237
71210772
7121 1682
7121 0773
7121 1683
7121 1685
7866907200
7866907201
FRENCH LABELS
OPTION L01
71210771
7121 2236
03211
03211
03211
03211
03211
03211
03211
28480
28480
03211
03211
03211
03211
03211
03211
03211
28480
28480
7121 0771
7121 2237
71210772
7121 1682
71210773
7121-1683
7121 1685
7866907200
7866*07201
7121 0771
71212236
71210772
7121 1700
7121 0773
7121-1701
7121-1703
7866907200
7866*07202
DUTCH LABELS
71210771
7121 2238
71210772
7121 2193
03211
03211
03211
28480
28480
PANEL OVERLAY DU
03211
03211
03211
03211
LABELINFO
LABELINFO
LABELWARNING
LABEL WARNING
LABEL WARNING
LABELWARNING
LABELWARNING
71210773
7121 2192
7121 2190
7866907200
7866907203
PANEL OVERLAY
2
5
71210771
7121 2238
7121 0772
71212193
7121 0773
7121 2192
71212190
7866907200
7866907203
8-6
Reference
Designation
HP Part
Number
Qty
LABEL CSA
LABEL INFO
7120 6645
7121 0771
CSA
OPTION NOI
Description
LABEL-WARNING
7121 1841
7121 2215
81201378
81201992
7866060240
7866960240
7866960241
LABEL INFO
CBL ASSY 18/3
CBL ASSY 8 FT
LABEL
PC AY BAT CHGR
PC AY CSA CHGR
LABEL VDE ID
71207115
VDE IEC CONFIGURATION
OPTION N02
Mfr
Code
03211
03211
03211
03211
28480
28480
28480
28480
28480
SECTION VIII - OPTIONS
Models 78670A/78671A
78670A-4
Mfr Part Number
71206645
71210771
7121 1841
7121 2215
8120 1378
8120 1992
7866060240
7866960240
78669 60241
UK POWER CORD
PWR CBL B5 1363
CBL ASSY 18 3
81201351
8120 1378
28480
28480
8120 1351
81201378
AUSTRALIAN POWER CORD
CBL ASSY 18 3
CBL ASSY
81201378
81202104
SWISS POWER CORD
OPTION 906
POWER PLUG AUST
CBL ASSY ASC 112
CBL ASSY 18/3
CBL ASSY3COND
12513921
8120-1396
81201378
81201689
28480
28480
28480
28480
28480
28480
12513921
81201369
81201378
8120 1689
81201378
81202104
TNG FILM UMATtC
TNG FU M VHS
TNG FILM BETA
8-7
SECTION Vm - OPTIONS
Models 78670A/78671A
78670A-1
NOTES
(*
8-8
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