LAB Manager - Electrical and Computer Engineering

LAB Manager - Electrical and Computer Engineering
FLORIDA INTERNATIONAL
UNIVERSITY
ELECTRICAL & COMPUTER ENGINEERING
LAB INSTRUMENTS USER MANUAL
Florida International University
ECE LAB Instruments Manual
Contents
1. Digital Multimeter-HP34401A ..…………………………………………………….…………………….… 6
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Quick Start……………………………………………….…………………………………….………………. 6
Introduction.......................................................................................................................................................... 7
Resistance Measurement ......................................................................................................................... 9
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Two-wire Method…………………………………………………………………………….… 9
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Null Function................................................................................................................................... 9
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Range Selection……………………………………………………........................................... 10
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Min/Max and Average………………………………………….…………………………... 11
Resistance Color Code and Power Rating…………………………………………………….. 11
Voltage Measurement…………………………………………………………………………………….13
Current Measurement................................................................................................................................. 14
Frequency Measurement……………………………………………………………………..………… 16
Specifications……………………………………………………………………………..……………...….. 17
2. Programmable Power Supply-HP E3631A……………………………………………………… 18
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Quick Start…………………………………………………………………………………………………….. 18
Introduction………………………………………………………………………………………………….... 18
Basics of Power Supplies: CV, CC and CV/CC…………………………………………... .18
HP E3631A Triple Output DC Power Supply..................................................20
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A Simplified View of a Power Supply……………………………………………... 21
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Constant Voltage…………………………………………………................................ 22
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Constant Current……………………………………………………………………………….. 23
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Disabling the Outputs……………………………………………….......................... 23
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Other Features…………………………………………………….................................. 23
Specifications ……………………………………………………………….................................. 24
3. Digital 2 Channel 100 MHz Osciloscope-HP54600B……………………......................... 25
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Quick Start……………………………………………………………………………………………………. 25
Features………………………………………………………………………………………………………… 26
Getting Familiar with the Scope…………………………………………………………………... 27
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Front Panel Controls ……………………………………………………………………….. 27
Display Features………………………………………………................................................. 27
Helpful Hints…………………………………………………………………………………… 28
Setting Probe Attenuation Factor……………………………………………………. 28
List of Procedures………………………………………………………………………………………... 28
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Adjusting The Oscilloscope Display………………………………………………. 29
Vp-p.................................................................................................................................................... 29
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Vrms………………………………………………………………………………………………… 29
Frequency……………………………………………………………………………………….... 29
Period………………………………………………………………………………………………. 30
Risetime ……………………………………………………….…………………………………. 30
Offset..................................................................................................................................................30
Selecting the Trigger Source……………………………………………………............ 30
Setting the Trigger Mode………………………………………………………………… 30
Averaging………………………………………………………………………………………… 31
Measuring Signal Amplitudes…………………………………………………………. 31
Measuring the Phase Shift between Channels………………….........................31
Taking Measurements (Examples)……………………………………........................................ 32
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Peak-Peak Voltage Measurements………………………………………………….. 32
Rise Time……………………………………………………........................................................32
Rise Time With Delayed Sweep……………………………………………………... 33
FFT………………………………………………………………………………………………….. 33
Storing Waveforms…………………………………………………………………………. 34
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Auto Store………………………………………………............................................ 34
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Saving to Trace Memory…………………………………………………….. 34
Specifications………………………………………………………………………………………………36
4. Function Generator/Arbitrary Wave Generator-HP33120A………................ 37
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Quick Start………………………………………………………………………………………….………. 37
Introduction ……………………………………………………………...................................................... 37
Basics of the Function/Waveform Generator (HP 33120A) ……………….…….. 40
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Functions and use of HP 33120A………………………………............................. 42
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Front Panel Menu
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Front Panel Number Entry………………………………………………… 42
Selection of Standard Functions ………………………………………. 43
Frequency Selection………………………………………………………….. 43
Amplitude Selection………………………………………………………….. 43
Offset Selection………………………………………….....................................44
Duty Cycle Selection………………………………………………………... 44
Output of an Arbitrary Waveform……………………………………. 44
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Selection of the Output Impedance (50 Ohm or High Z)…… 45
Advanced Modification of a Standard Waveform …………….. 45
Storing Arbitrary Waveforms………………………………………………………… 47
Specifications…………………………………………………………………………………………….. 48
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5. HP 53131A DC-225MHZ 10 Digit Universal Counter...............……….49
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Quick Start………………………………………………………………...................................................... 49
Key Features……………………………………………………………………………………………….. 50
The Front Panel at a Glance………………………………………………………………………... 51
The Front Panel Indicators at a Glance………………………………………………………. 52
The Front Panel Menus at a Glance…………………………………………………………….54
Making Measurements……………………………………………………………………………….. 56
To Control Measurement………………………………………………............................................. 72
6. Function/Arbitrary Waveform Generator HP33220A 20 MHz…………73
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Specification……………………………………………………………………………………………..... 73
The Front Panel at a Glance………………………………………………………………………. 74
The Front Panel Display at a Glance…………………………………..................................... 74
Front-Panel Number Entry……………………………………………............................................ 75
To Set Output Frequency…………………………………………………………………………... 76
To Set Output Amplitude................................................................................................................... 77
To Set a DC Offset Voltage………………………………………................................................. 78
To Set the High-Level and Low-Level Values……………………….............................. 79
To Set ‘DC Volts’…………………………………………………….................................................... 80
To Set the Duty Cycle of a Square Wave…………………………….................................. 80
To Configure a Pulse Waveform…………………………………………………….…………. 81
To View a Waveform Graph………………………………………………………………….….. 82
To Output a Stored Arbitrary Waveform…………………………………………………... 82
To Use the Built-In Help System………………………………………………………………. 83
To Select the Output Termination……………………………………....................................... 84
To Output a Modulated Waveform…………………………………….................................... 84
To Output an FSK Waveform………………………………………............................................ 86
To Output a PWM Waveform…………………………………………........................................ 88
To Output a Frequency Sweep…………………………………………....................................... 89
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1. Digital Multimeter-HP34401A
QUICK START
Turn ON the unit; the unit will test itself and will show Adds # 22. Also, will set to mV
(milivolts) which is the default.
DC (Default).
The unit will also be set at Auto Range (Automatic Voltage Reading) which will allow you to
check any voltage from 0 to 200V DC at the 200 V terminals, and 0 to 1000V DC at the 1000 V
terminals ( Red buttons at front panel).
Note: For any voltage over 30V, check with the instructor “BEFORE YOU ATTEMPT
TO MEASURE.
To measure AC Voltage, press the AC voltage button and be sure that the leads are now in the
correct position for the correct amount of voltage to be measured.
Note: See the Lab instructor if any doubt.
For DC current, press the blue (shift) button, then V DC Volt button. Before this test, leads must
be placed as fallows:
Positive lead to the current terminal (Red button outlet) while the ground lead remains at the
same position.
Note: To measure currents, the meter must be in series with the part of the circuit
under test. Never measure current across a circuit component.
To measure AC Current, press the blue (shift) button and AC Volt button.
Remember, test cables must be placed in correct terminals to measure currents.
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To measure current at any part of your circuit on the board, connect the multimeter in series with
the components or wire in that part of your circuit. Do not connect the meter across (in parallel)
any component or wire. See your lab instructor for help.
NOTE:
For any current over 1 Amp, see your Lab Instructor
for assistance, BEFORE YOU MEASURE!
To check Resistance:
First, be absolutely sure that there is “NO” POWER” connected to the resistance under test. It
is recommended to place the resistor(s) at an empty part of the Proto Board, not
connected to the other part of the circuit, to do the measurement.
Leads will be place as if were to measuring voltage, press the Ω from the front panel
After the measurement has been made, reconnect the right resistance(s) back into the circuit, and
then, reconnect the power.
NOTE:
Range at the resistance meter’s panel is auto, but can be adjusted manually
By pressing the arrows (▲, ▼) at the front of the unit ‘s panel .
See below for more details.
Figure 1: Measurement of resistance, voltage and current with a multimeter
Introduction
One of the most important functions of ECE Lab is to provide an understanding of the functions
of instruments. For ECE students, this knowledge is essential to conduct laboratory assignments
and develop independent design projects.
Currents and voltages are the basic circuit variables of interest. In this Lab we are mainly
concerned with accurately measuring resistance, DC voltage and currents using a digital
multimeter (DMM). We will use the HP34401A digital multimeter which is a high performance
instrument capable of measuring resistance, DC and AC voltage and current, as well as
frequency. The HP34401A has a built-in microprocessor, memory and other electronics
components that give it numerous features such as built-in math functions, recording and storing
up to 512 readings, giving the maximum, minimum and average of the readings. In addition, it
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can be remotely programmed using the SCPI (Standard Commands for Programmable
Instruments) language and read by computer via a General Purpose Interface Board (GPIB) port.
The use of the instrument for measurement of resistance, current and voltage is in principle very
simple. Figure 1 shows the set up for resistance, voltage and current measurements.
For resistance measurements, one connects the DMM over the resistor. Notice that for voltage
measurements one puts the multimeter in parallel with the circuit element so that one measures
the voltage across the element. In case of a current measurement, one must put the DMM in
serial with the element in order to measure the current through the element. That involves
breaking the circuit in order to insert the multimeter in the circuit loop.
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Resistance measurements with the HP34401
To Measure Resistance
Ranges: 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 M Ω, 10M Ω, 100MΩ
Maximum resolution: 100 µ Ω (on 100 ohm range)
4 wire measurement
4 Wires
Ω 4W
Ω 2W
Shift
Principle of 2 wire measurement
The DMM measures a resistance by applying a known DC voltage over unknown resistance in
series with a small resistance Rm . It measures the voltage over the resistance Rm as shown in
Figure 2. The DMM can then calculate the unknown resistance R.
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Figure 2: Two-wire resistance measurement
To use the DMM for resistance measurements, connect the resistor to the terminals labeled HI
(V Ω)and LO, select the resistance measurement function by pushing the [Ω] button (one of the
function keys) on the front panel as shown below in Figure 3. Please notice that the selection
keys are annotated in black and blue. To select the function in blue, please press the blue SHIFT
key.
Figure 3: Function buttons to select resistance, voltage, current or frequency
Measurement errors and Null function.
If using DMM to measuring the small value of resistor with cables, the resistance of cables may
even larger than small resistor. The HP34401A DMM can overcome this problem by using the
Null feature. The front panel of the DMM (see Figure 3) has a ‘Null’ button. To null the wire
resistance, short the ends of the test wire and then press the ‘Null’ button. You can disable the
Null function by pushing the button again.
CAUTION: To test resistance, the safest way is disconnect all voltage sources before
connecting the DMM to the circuit. A large voltage input terminals of the DMM may damage
the meter.
Range selector
The multimeter automatically selects the range using the auto-ranging feature. However, you can
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also manually select a fixed range (e.g. 1KΩ or 1MΩ) using the Auto/Man button on the front
panel (under Range/Digits) buttons (Figure 4). The 'down' arrow selects the lower range and the
'up' arrow the higher range.
Figure 4: Function, Math, Range, and Menu keys
Additional features of the HP34401A: average, max and min value
To find the average value, maximum and minimum values of variable test points, HP34401A has
built-in features. To enable this feature, push the Min/Max button (one of the Math buttons) on
the front panel. The Math annunciator will lit on, and DMM will make short beeps indicating it
is taking readings and storing the MAX, MIN, Average value, and the total COUNT. Push the
Min/Max button again to stop the readings.
To access these stored numbers, just turn the Menu on by pressing the On/Off key (SHIFT <) on
the front panel (see Figure 4). Then, use the > or < keys until you are in the MATH (B) menu.
You can now go down to the "parameter level" of the selected MIN-MAX menu by pressing the
"down" button until you see the desired parameter menu (1:MIN_MAX) displayed. Press "down"
button again, you are in the MIN-MAX menu. Please use the > or < buttons to scroll through the
menu and read the values. The menu is organized in three levels, as Fig. 5.
Figure 5: The front panel menu organization.
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The MIN-MAX feature can be used for resistance measurements as well as for voltage, current,
and frequency measurements.
The resistance color code and power rating
Resistors are usually color coded using color banding as shown in Figure 6. Two digits and a
power 10 multiplier determine the resistance value. The color band on the most left is the 1st
significant digit, followed by the 2nd digit and the multiplier. The fourth band is usually present
as well and indicates the tolerance of the specified resistance.
Figure 6: The 5% Resistor Color Code.
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Power rating of resistors
In addition to the value and tolerance of a resistor, the power rating is another important
characteristic. It tells how much power the resistor can dissipate before being damaged by
overheating. Resistors come in different power ratings: 1/8, 1/4, 1/2, 1 and 2 Watts are typical
values.
Voltage measurement
Ranges: 100mV, 1V, 10V, 100V, 1000V (750 Vac)
Maximum resolution: 100nV (on 100 mV range)
AC technique: true RMS, ac-coupled
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AC or DC Voltage
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Principle of measurement
A DC voltage is measured by using a voltage amplifier and an analog-to-digital converter as
schematically shown in Figure 7. A microprocessor further manipulates the data before
displaying the results.
Figure 7: Schematic of the DMM as a DC voltage meter.
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To measure a voltage, connect the nodes over which one wants to measure the voltage between
the HI and LO input terminals of the DMM (Figure 3). In order to activate the DMM for DC
measurements you have to select the DC Voltage function by pushing the DC V button on the
front panel (see Figure 3). The Math functions, such as Max/Min and average, can be activated
in a similar fashion as was done for the resistance measurements. Also, the range can be selected
manually by pushing the Man/Auto key in the Range menu.
If you have the probes connected for measuring currents and you try to measure the voltage of
low-impedance voltage source (such as power supply), you will blow a fuse in the instrument. In
order to avoid this, always remember to check the connection of your probes before making
voltage measurement.
Errors due to the internal resistance
An ideal voltmeter has an infinite input resistance so that it will not draw any current from the
circuit under testing. However, in reality, there is always a finite input resistance Ri, as shown in
Figure 7. As a result, one has a voltage divider that will cause the voltage Vm one sees at the
input of the voltmeter to be slightly different from the actual voltage VS one wants to measure.
The HP34401A has a relatively large input resistance of at least 10Mohm (depending on the
selected voltage range) so that the error will be small as long as Rs << Ri.
CAUTION: Do not exceed the maximum allowable voltage input (1000V DC). Also, never
apply a voltage over the current input terminal (I) of the DMM.
Current measurement
To Measure Current
Never connect across any component or supply!
Range: 10 mA ( DC only), 100 mA( DC only), 1A, 3A
Maximum resolution: 10 nA (on 10mA range)
AC technique: true RMS, AC-coupled
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Principle of the measurement
An ammeter senses the current flowing through its input terminals. The ammeter (or DMM)
must be connected in series with the circuit such the same current flows through the DMM and
the test circuit. The principle of the current measurement is quite simple. The ammeter has a
small resistance at its input terminals and measures the voltage that the test current generates
over this resistance (Figure 8).
Figure 8: Principle of DC current measurement.
To use the DMM as an ammeter, one connects the leads in which the current flows to the current
(I) and Lo terminals (see the front panel in Figure 3). To activate the ammeter, one must also
select the DC I key by pushing SHIFT and DC V button as shown in Figures 3 or 4.
Error due to the non-zero input resistance
An ideal ammeter has a zero input resistance so that it does not disturb the current under test.
The small input resistance will cause a small voltage drop which gives a small error. Fortunately,
the input resistance of the HP34401A is pretty small (Ro = 0.1Ω for 1 and 3 A range, and 5 Ω for
the 10mA and 100mA ranges) and can, in most cases, be ignored as long as R >> Ro.
CAUTION: Do not exceed the maximum allowable current input (3A DC). Also, never apply a
voltage over the current input terminal (I) of the DMM. This will cause a large current to flow
through the small input resistor Ro and can damage the DMM.
Frequency measurement
To Measure Frequency (or Period)
Measurement band: 3 Hz to 300 KHz (0.33 sec to 3.3µsec)
Input signal range: 100 mVac to 750 Vac
Technique: Rrecip
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AC or DC Voltage
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Specifications (HP 34401A)
DC Characteristics:
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DC Voltage range and input resistance:
0.1V, 1V, 10V: input resistance selectable 10MΩ or > 10GΩ
100V and 1000V: Rin = 10MΩ
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DC Current range and shunt resistance:
10mA, 100mA: Rshunt= 5 Ω
1A and 3A: 0.1 Ω
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Resistance range: 2-wire and 4-wire method
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100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 MΩ and 100 MΩ
Input protection: 1000V
AC Characteristics: true RMS
AC Voltage: from 3 Hz to 300 kHz (for accuracy specs consult the manual)
AC Current from 3 Hz to 5 kHz
Frequency and Period measurement:
Frequency range: 3 Hz - 300 kHz
Input voltage range: 100 mV to 750 V
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2. Programmable Power Supply-HP E3631A
Quick Start
Do not connect to your circuit yet!
Turn the unit On. The unit will self test and show you Addr )%, then will go to the default
setting: 6 V DC (max). The unit is ready to operate. Power will be accessible from the 6 V outlet,
(+ - ); voltage can be adjusted by moving the blinking digits with the arrows (→ ←)and turning
wheel from the from panel. Once the output voltage is adjusted, turn the power OFF, inspect
your circuit for any mistakes; then proceed to turn the output voltage ON.
NOTE: Turn the Output voltage OFF before you make any changes on your circuit board.
For higher voltage, use the ± 25 V (max) terminals. Sert the 25 + voltage first by pressing the
+25V from the front panel, turn the output voltage On , then, turn the adjusting knob to the
desired voltage. After reaching the desired voltage, turn the output voltage Off.
For the -25V (max), press the -25 V key from the from panel, turn the voltage On, them turn the
adjusting knob to the desired voltage. Then turn the voltage output Off.
Now, you are set to connect power to your circuit board.
Before turning On the output voltage, re-check your circuit for any problem; after that, turn your
OUTPUT VOLTAGE ON.
Make any measurements necessary, after finishing, PLEASE TURN THE UNIT OFF.
NOTE:
If any problem occurs while working in your circuit, turn the output voltage Off,
re-check your circuit (more carefully), fixed if any problem and then re-connect
the power ON.
Also, make sure the supply is set for enough current your circuit.
See below for more details.
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Introduction
Hewlett-Packard E3631A triple output power supply It is a 80-watt triple output supply and
offers three independent 0 to +6V/5A and 0 to +/-25V/1A outputs. The 6V output is electrically
isolated from the +/-25V supply to minimize any interference between circuits under tests.
+/-25V outputs can be set to track each other. E3631A is dependable regulation and fast transient
response with built-in GPIB and RS-232 interface.
Basics of Power Supplies
A regulated power supply provides electrical energy which is precisely controlled. Power
supplies can be of the type Constant-Voltage, Constant-Current, and the Constant-Voltage
/Constant-Current sources. A Constant-Voltage (CV) supply provides a DC voltage that can be
set to any desired value over a specified range. An ideal constant-voltage supply has a zero
output impedance, as illustrated in Figure 1a. On the other hand, a constant-current (CC) supply
gives a regulated current independent of the voltage over the load (up to the maximum allowable
voltage), as shown in Figure 1b.
Figure 1: Output characteristic of a constant-voltage (a) and constant-current (b) supply.
A more versatile power supply is the Constant-Voltage/Constant-Current supply which can be
used to provide either a constant voltage or a constant current. Figure 2 illustrates the I-V
characteristic of such a supply. The values Vs and Is are selected by the operator from the front
panel or programmed through the GPIB interface.
Figure 2: Output characteristic of a constant-voltage/ constant-current supply.
Let’s look at the operating modes of CV/CC power supply. Assume that one connects a resistive
load to the power supply as shown in Figure 3. The supply has been set at a voltage V=Vs and
current I=Is. The current through the resistor: I=V/R. As long as the current is below the
maximum value Is, the voltage over the resistor will be constant and equal to Vs. The power
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supply operates thus in the CV mode as shown in Figure 3. However, if one decreases the
resistance such that the current exceeds the maximum allowable value Is, the current will be
limited to Is and the power supply operates in the CC mode. The resistance Rc=Vs/Is is called the
critical resistance and determines whether one operates in the CV (RL>Rc) or CC (RL>Rc) mode.
Figure 3: Operating point of a CV/CC power supply.
HP E3631A Tr iple Output DC Power Supply
The HP E3631A is a constant-voltage/constant-current type and can be adjusted to various range
controls of the power supply on both positive and negative voltages.
Figure 4 shows the front panel of the HP E3631A. Italicized print indicates the switch functions.
The shaded switches control more advanced features built into the equipment and will not in this
write-up.
Figure 4: Front panel of the HP E3631A triple output power supply.
The power supply has a triple output: +6V/5A, +25V/1A and -25V/1A supplies. These outputs
(binding posts) are located at the bottom right of the front panel (see Figure 4). In addition, the
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power supply has an earth ground terminal (with ⊥ sign) which is connected between chassis and
earth ground by 3-wire ground receptacle. This is for safety considerations.
A Simplified View of a Power Supply
Let’s look at the power supply in the constant-voltage (CV) mode. A CV power supply can be
considered to be a "near-ideal" battery with a very low internal resistance. Its voltage will remain
constant if its current rating is not exceeded. Figure 5 illustrates this view of the power supply.
The +25V and -25V outputs have a common output terminal (denoted by "com") which is
isolated from the case or chassis ground. The positive or negative terminals of each output can be
grounded or each output can be left floating with respect to the ground (must be kept within +/240V from the chassis ground).
Figure 5: Simplified view of the triple output power supply
Figure 6 shows the case where one uses the +25V, -25V and -6V power supplies in one circuit.
All supplies have a common connection (the reference node) which can or cannot be connected
to the ground. ( For most circuits, our reference node is grouded).
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Figure 6: Power supply connection using the three power supplies; the top figure shows the
actual connection and the bottom one gives the circuit schematic.
Constant Voltage(CV) Operation
1. Turn the power supply on. Output of power supply is disabled as default. ‘OFF’
annunciator is on.
2. Enable the outputs by pressing the Output On/OFF key (see Figure 7) The CV and
+6V annunciators is on and +6V is selected. You can adjust the blinking digit to
select the desired output voltage by turning the knob on the top right of the front
panel. The display is in the meter mode, and shows the actual output voltage and
current.
3. To set up the +25 V power supply, press the +25V key to select the display and adjust
the +25V supply voltage, same way to adjust -25V supply.
To Set Limit Mode:
The next step is to select the maximum current (limit I). Setting the current limit will
ensure that the supply can provide enough current and does not go into the constant
current mode. It will protect your circuit from drawing too much current and from being
damaged.
1. Set the display for limit mode by pressing the Display Limit key. ‘LMT’ annunciator
is blinking. The display shows the actual voltage and current limit values of the
selected supply.
2. Connect the desired circuit to the power supply's output terminals.
3. Press the Vol/Cur key. The second digit of the ammeter will be blinking. Adjust the
knob to set the desired current limit (make sure the ‘LMT’ annunciator is still
blinking). Using ‘>’ or ‘<’ buttons to switch to another digit.
4. When you press the Vol/Cur key again the voltage digit will be blinking. You can
now adjust the voltage output.
5. Return to the meter mode by pressing ‘Display Limit’ key or let the display time-out
and back to the meter mode automatically.
Figure 7: Front panel selections
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NOTE: to check that you are operating in the constant voltage mode for the +25V or -25V
supplies make sure the +25V or -25V annunciator is on. For the +6V supply, the +6V and CV
annunciators will be on. If the CC annunciator is on, choose a higher current limit.
Constant Current (CC) Operation
The power supply can be used as a current source.
1. Turn on the power supply. The power supply's outputs is disabled (The annunciator
of ‘OFF’ is on) as default.
2. Enable the outputs by pressing the Output On/OFF key (see Figure 8) The CV and
+6V annunciators is on, +6V is selected. The display is in the meter mode and shows
the actual output voltage and current.
3. To set up the +25 V power supply, press the +25V key to select the display and adjust
the +25V supply voltage by knob, same way to adjust -25V supply.
4. Turn off output by pressing ‘Output On/OFF’ key.
5. Connect the desired circuit to the power supply output terminals.
6. Turn on output by pressing ‘Output On/OFF’ key.
To Set Limit Mode :
1. Set the display for limit mode by pressing the Display Limit key. You will notice the
LMT annunciator blinking to indicate that the display is in the limit mode. The
display shows the actual voltage and current limit values of the selected supply.
2. You will notice that the second digit of the voltmeter is blinking. Turn the large knob
to set the desired voltage limit (make sure the LMT annunciator is still blinking).
3. Press the Vol/Cur key. The second digit of the ammeter will be blinking. Adjust the
desired output current that the current source will supply.
4. To return to the meter mode press the Display Limit or let the display time-out, it
will automatically back to meter mode. The LMT annunciator will be off.
NOTE: To verify that you are operating in the constant current mode make sure the +6V and
CC annunciator is on if you are using +6V supply, the +25V or -25V annunciator is on if using
+25V or -25V supply. If the CV annunciator is on, choose a higher voltage limit.
Disabling the Outputs
Sometimes you need to disable the voltage or current outputs. This can be done without turn off
the power supply so that you do not lose the settings. To disable the outputs, press the Output
On/OFF key. The OFF annunciator will go on. To enable the outputs, press Output On/OFF
again.
Other features.
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The HP E3631A has several other useful features. They include tracking operation (the +25 and 25V outputs track each other); storing and recalling operating states (up to 3 different settings
can be stored); system related controls, and remote interface configuration (GPIB and RS-232).
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3. Digital 2 Channel 100 MHz Osciloscope-HP54600B
QUICK START
Turn ON the unit, after the self test, this unit will display Normal Screen.
NOTE:
Before any reading is made, press the SET-UP key, all the soft keys under the screen
are displayed now.
Press the default set-up key, then save the setting by pressing the save key from the soft key
panel under the screen.
Now you are ready to use this unit!
When the unit is connected to any Source, (or your circuit) or from the OUTPUT of the Function
Generator, it will display your signal at the scope. Pressing the auto range key, you will have a
better look of the signal at the scope
To measure the Amplitude of the signal:
Press the Voltage key from the from panel of the scope; all the soft keys under the scope screen
will change to:
Source( 1 & 2), Vp-p , Vavg , Vrms are now available. By pressing any of these keys, the unit
will show them. Clear them (any measure you did) by pressing the Clear_Meas key; then the unit
is ready for new set of measurements instructions.
If any adjustment in the circuit is needed, turn off the power source, make the required change,
restart the power supply, and press the auto-scale key for a new set of measurements.
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To Measure Frequency:
Press the Time Key, you are now in time domain mode, all the soft keys under the screen will
change to Source (1 & 2), frequency, Period, Duty Cycle. All these measurements can be made
by pressing the key for the desired task. If new measures are needed, adjust the circuit (if
necessary), press auto scale key, and continue with your measurements.
Note: Change the source for the proper reading of your input (Channel 1 or Channel 2).
Other measurements possible with the scope are Voltage (eg, rms) or Time (T1 and T2) can be
made by pressing the Cursor key and take the cursor to the desired type of measure (horizontal or
vertical value).
Accordingly with the Mode selected at the moment of this operation, you will be able to check
(Voltagepp ) if in Voltage Mode by moving the cursor knob for up or down. If in Time Mode, T1
and T2 can be measured by moving the left or right knob for T1 or T2 values.
Note: After using these units, be sure “ALL of these units are turned OFF” before you
leave the lab.
Before attempting to operate this unit as Spectrum Analyzer see your Lab Instructor
for HELP !
See below for more details.
Features
•
•
•
•
100 MHz bandwidth
2 Channels
Sweep speeds from 5 s/div to 2 ns/div
Up to 1.5 Million points/sec screen update rate
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Getting Familiar with the Scope
Front Panel Controls
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Display Features
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List of Procedures
The procedures used in the processes of making measurements with the HP 54645A
oscilloscope in the various labs are listed in this section for easy referencing.
Adjusting the Oscilloscope Display
•
Press
OR
•
Press
•
•
•
•
•
•
•
and press the leftmost softkey until On is highlighted
Press
Position the signal on the display using the position knob
Adjust Time/Div until at least 2 periods are displayed
Change the vertical sensitivity with the Volts/Div knob until the waveform fills the
display without clipping
and press the leftmost softkey until On is highlighted and repeat previous
Press
Steps
followed by the Full softkey
Vp-p
1. Hook calibrator signal to CH1
2. Press
key
3. Press Voltage Key
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4. Press soft key Vp-p
5. Vp-p value will move toward to the bottom left on the screen.
Vrms
1. Hook calibrator signal to CH1
2. Press
key
3. Press Voltage Key
4. Press soft key Vrms
5. Vrms value will move toward to the bottom midle on the screen.
Frequency
1.
2.
3.
4.
Press
key
Press Time Key
Press Frequency soft key
Frequency value will move toward to the bottom left on the screen.
Period
1.
2.
3.
4.
Press
key
Press Time Key
Press Period soft key
Period value will move toward to the bottom on the screen.
RiseTime
1. Press
key
2. Press
Key
3. Press
soft key
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4. Press soft key RiseTime
5. RiseTime value will move toward to the bottom on the screen.
6. If answer needs more resolution, rotate for best display:
Offset
1.
2.
3.
4.
Press ‘ ±’ key
Press soft key Menu
Press Soft key Offset
Use the Cursor knob to adjust
Selecting the Trigger Source
1. Press
2. Press the softkey corresponding to the desired source
Setting the Trigger Mode
1. Press
2. Press the softkey corresponding to the desired mode
Averaging
To turn averaging on:
1. Press
2. Press the Average softkey
3. Press the # Average softkey until the desired number of averages is selected.
To turn averaging off:
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1. Press
2. Press the Normal softkey
Measuring Signal Amplitudes
1. Press
2.
3.
4.
5.
Press the Clear Meas softkey to clear the last measurement
Press the Source softkey until channel 1 is selected
Press the Next Menu softkey until the VAMP softkey is displayed
Press the VAMP softkey to display the amplitude of the waveform
6. Repeat for channel 2 (Don’t clear the last measurement)
Measuring the Phase Shift between Channels
1. Press
2. Press the Next Menu softkey until the Define Thresholds softkey is displayed on
the far left side of the screen
3. Press the Measure Phase softkey
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Taking Measurements (Examples)
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FFT
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Specifications
HP 54600B Performance Characteristics
Form Factor
Bench top
Bandwidth
100 MHz
Number of Channels
2 ch
Simultaneous Channels
2 ch
Simultaneous Maximum Sampling Rate/Ch
20 MSa/s
One Ch. only max. sampling rate
20 MSa/s
Max. Single Shot bandwidth
2 MHz
Max. Record Length
4000 pt/sec
Min. Vertical Sensitivity
2 mV/div
Maximum Vertical Sensitivity
5 V/div
Rise time
3.5 ns
Number of Bits
8 bits
Input Impedance
1 MΩ
Input Coupling
AC,DC,GND
Maximum Input Voltage
400 Vrms
Main time base - lowest
2 ns/div
Main time base - highest
5 s/div
Time base accuracy
0.01 %
Trigger Source
External, Internal
Trigger Modes
Auto, Single, Trigger
Trigger Sensitivity
3.5 mV
Minimum Glitch Trigger
1 ns
Display Type
CRT Monochrome
Display Size
17.78 cm
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4. Function Generator/Arbitrary Wave Generator
- HP33120A
QUICK START
Turn ON the unit, it will self test and Addr 10 will come on.
1 KHz at 100 mVpp sinusoidal is the Default for this unit.
The shape of the signal can be changed by pressing the proper key from the front panel of the
unit.
To change the frequency: Press the frequency key, then, rotating the knob at the front panel
will adjust the frequency from 0.1 Hz to 15 MHz.
To change the magnitude of the signal: Press the Amplitude (Amp) key. Rotate the same knob
used to adjust frequency, and select the desired unit (Hz, KHz, MHz), until you reach the desired
frequency.
For Signal Modulation Mode (AM, FM, FSK):
Press the blue key (+ AM). From the
scope, rotate the Time/Division knob until the signal appears at desired shape. You can stop the
scope to have a better view of the modulated signal by pressing stop key from the front panel of
the scope. After viewing the signal, press the Run key.
To change the amount of modulation; while in modulation mode, press the (blue key + the Amp
(level) key). By rotating the adjustment knob will change the % of modulation from 1 to 120 %
of modulation.
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Note: When connecting the generator to the scope, be sure that the correct measurement is read,
adjust the Function Generator to High Impedance reading with these steps:
1. Press Blue Key then Enter
2. Press 3 times the ► key
3. Press 2 times ▼ key.
4. Press 1 time ► key.
5. Finally, press the Enter Key
The unit is now in High Impedance and in Sync with the scope!
Also, remember to press the Auto-Scale at the scope to reset the measurement.
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Introduction
A function generator allows you to create a wide variety of synthesized electrical signals and
waveforms. Figure 1 shows the most common functions such as the sine, square, triangle and
ramp functions.
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Figure 1: Waveforms generated by a function generator
Each of the waveforms can be adjusted through the front panel controls or remotely for
frequency, amplitude and DC offset voltage. For example, a sine function described by the
following equation,
v(t)=VAsin(2*pi*ft) + VOFF
in which ‘f’ is frequency, VA the amplitude, and VOFF if the offset voltage as shown in Figure 2.
Instead of amplitude one often uses the RMS (Root Mean Square) value to express the signal
voltage level. For a sine wave the RMS value is the amplitude divided by the square root of 2 or
VRMS = VA/1.41. The RMS is the most useful way to specify AC signal amplitudes.
Figure 2: Sine wave with amplitude VA , frequency f, and offset VOFF
The generator can be remotely programmed and read by computer via a General Purpose
Interface Board (GPIB).
Basics of the Function Generator (HP33120A)
The function generator in the ECE lab is based on digital signal processing (DSP) methods. The
DSP is able to generate complex and arbitrary functions. A simplified block diagram is shown
in Figure 3.
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Figure 3: Block diagram of the HP33120A waveform generator.
Any circuit can be represented by the Thevenin's equivalent circuit. This is shown in Figure 4a.
Vgen represents the waveform (sine, pulse, etc.) and RT is the Thevenin resistance (= output
resistance).
Figure 4: (a) Thevenin's equivalent circuit; (b) voltage divider between the output and load
resistors.
Important is that this output resistance of the function generator is 50 Ohm. This implies that
the actual output voltage one measures over the load will var y with the load r esistance because
of the voltage divider, as shown in Figure 4b. The output amplitude is calibrated for a 50 Ohm
load resistance, which means that the voltage shown on the function generator's display panel
corresponds to the actual voltage VLOAD over the load only when the resistance is equal to 50
Ohm. In other words, the value of Vgen is double of the value displayed (or selected) by the
function generator. If the function generator's output is measured with no load connected (=open
circuit or infinite resistance), the output voltage will be twice the displayed amplitude. Thus, be
careful when applying the output voltage of the function generator to a circuit which input
resistance is different from 50 Ohm.
To get accurate test result, you have to set function generator to high-impedance load
(High-Z) mode.
How to set function generator to high-impedance load (High-Z) mode, please refer II.2.a.
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Functions and Use of HP 33120A
The front panel of the HP 33120A is shown in Figure 5. There are two outputs on the right of
front-panel. One is ‘OUTPUT’-- the regular output terminal at which the specified waveform
appears. The other output ‘SYNC’ is often used as a trigger signal. Both output terminals are of
the "BNC" type, which can be connected to a coaxial cable (a shielded cable).
Figure 5: Front panel of the HP 33120A function generator/Waveform generator
a. F ront Panel Number Entry
To set the amplitude, frequency and offset voltage of a waveform, just enter numbers. Numbers
can be entered in three ways:
1. Use big knob. One of the digits will be blinking on the display. During you turning
knob, the blinking number will increase or decrease.
2. Use the arrow keys ‘<’, ‘>’, ‘^’, ‘v’.
3. Use the ‘Enter Number’ mode. Press ‘ENTER NUMBER’ key, followed by the
number (see green number keys on the front panel) and the units, and then press
‘ENTER’ key(see Figure 6). To cancel the number mode, press ‘SHIFT’ and
‘CANCEL’ keys.
Figure 6: Entering numbers using the "Enter Number" mode.
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At power-on the function generator will output a sine wave of 1 KHz and amplitude of 100mV
peak-to-peak (for a 50 Ohm load resistance). You can select another function or change the
frequency, amplitude and offset voltage by pressing MODIFY keys.
b. Selection of a standard waveform
1. Press the key with the icon of the desired waveform (sine, pulse, triangle, or ramp) as
shown in Figure 5. An annunciator will show the selected waveform
2. Arbitrary waveforms can be selected, see details on coming section.
3. Press ‘Modify’ key to modify the amplitude, frequency (and duty cycle in case of a
pulse). See details on coming section
c. F requency selection
Procedure:
1. Press the ‘FREQ’ key (Figures 5 and 7).
2. Enter frequency with number key, the frequency annunciator will display.
3. Press one of the arrow keys to set the units (MHz, KHz, HZ).
Figure 7: Using the Modify Keys to select the frequency, amplitude, offset or duty cycle
d. Amplitude selection
Select the Amplitude Mode by:
1. Press the AMPL key (Figure 7).
2. Enter the number for the amplitude.
3. Press the arrow keys to select amplitude in (m) V peak-to-peak (VPP), in (m) V RMS or
dB.
Notice:
The function generator is calibrated for a 50 Ohm load which implies that the output voltage will
be different from the one selected when the load resistance is different from 50 Ohm.
The minimum amplitude is 50 mVPP and the maximum 10 VPP for a 50 Ohm load (and 100mVPP
and 20 VPP, respectively, for an open circuit).
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e. Offset Voltage selection
The waveforms default offset voltage is 0V, which means that the waveform will vary between a
positive and negative value. If you want to offset the waveform, you will need to add an offset
voltage as defined in Figure 2. To set the offset voltage:
1. Select the Offset Modify Mode.
2. Enter the number for the offset voltage.
3. Press ‘ENTER’ key.
f. Duty Cycle selection
This applies to square waves only, and default duty cycle is 50% and can be changed by:
1.
2.
3.
4.
Press the key with the square wave icon.
Press the ‘SHIFT’ and ‘%DUTY’ keys (see Figure 7).
Enter the number in %.
Press the ‘ENTER’ key.
g. Output of an arbitrary waveform
There are five built-in arbitrary waveforms stored in memory. It includes sinc, exponential rise
and fall, negative ramp and a cardiac function (which simulates the heart beat of human), refer
Figure 8. In addition, one of five waveforms can be user-defined.
Figure 8: The five built-in arbitrary functions
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To see the list of arbitrary functions:
1. Press ‘SHIFT’ key.
2. Press ‘ARB LIST’ key.
3. The first choice displayed is SINC. The display will show SINC for about 10 seconds.
Press the ‘>’ keys or Round knob to change the functions (EXP-RISE, EXP-FALL,
NEG-RAMP, and CARDIAC).
4. When the desired function is displayed press the ‘ENTER’ key.
5. Now, the amplitude, frequency and offset voltage are able to be changed.
6. Once you have selected an arbitrary waveform, this function will be assigned to the
‘ARB’ key. Every time you press ‘ARB’ key, this waveform will be selected.
7. And then, the parameters of this function can be changed.
Figure 9: Selecting the Arbitrary Functions by pressing the SHIFT and ARB LIST keys
Front-panel Menu of the HP33120A Waveform Generator
a. Selection of the output impedance (50 Ohm or High Z)
To get accurate test result, you have to set function generator to high-impedance load (High-Z)
mode. How to set function generator to high-impedance load (High-Z) mode:
1. Press ‘Menu On’ (Shift-Enter). You can see ‘A: MOD MENU’ on the display.
2. Press ‘>’ key three times, you can see ‘D: SYS MENU’ on the display.
3. Press ‘v’ key once, you can see ‘1: OUT TERM’ on display. It means ‘output
termination’—Resistance of your load.
4. Press ‘v’ again, you can see ’50 OHM’ on the display.
5. Press ‘>’ key, you can see ‘HIGH Z’ on display.
6. Press ‘Enter’, the equipment is set as high impendence loads.
To get ‘High-Z’, this procedure must go through by manually each time turn on the HP
33120A.
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b. Advanced modification of a standard waveform
Modulation waveform using amplitude or frequency (AM and FM), generate Frequency Shift
Keying (FSK) signal, frequency sweep, or a burst waveform.
The menu is organized in a top down tree structure as shown in Figure 10. You move down the
menu tree using the ‘^’ or ‘v’ keys, and move within a level using the ‘>’ and ‘<’ keys. The top
level lets you select the main functions, the 2nd level is the command level, and the 3rd level is
the parameter level.
Figure 10: Menu organization
•
•
•
•
To turn the menu on press the ‘SHIFT’ and ‘MENU On/Off ’ keys;
Press the ‘>’, ‘<’, ‘^’ and ‘v’ keys to navigate the menu;
To enter a command press the ‘ENTER’ key;
To recall the last menu command that was executed, press the ‘SHIFT’
‘RECALL_MENU’ keys.
Example: Advanced modification of standard waveforms
The standard waveforms can be modified to create more complex ones which can be used in
various applications. As an example, one can modulate the amplitude (AM) or frequency (FM)
of the waveforms in Figure 11 for an AM modulated sinusoid. The carrier frequency amplitude is
being modulated by the lower frequency - sinusoid, and is called modulating signal. The
modulating signal could be any signal (For example: a speech signal or music, as the case for
AM radio transmission).
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Figure 11: AM modulated sinusoid
To modulate a sinusoid:
1. Select the sine function by pressing the key with the sine icon.
2. Adjust the frequency and amplitude using the modify keys.
3. Select AM mode by pressing the ‘SHIFT’ and ‘AM’ keys (see Figures 5 and 12). AM
annunciator will be on.
4. Select the shape of the modulating waveform on ‘Menu’.
5. Press ‘SHIFT’ and ‘RECALL_MENU’ buttons, it will get in ‘AM’ menu and displays
‘AM SHAPE’.
6. Press ‘v’ to select ‘SINE’ waveform.
7. Press ‘ENTER’.
8. Set the modulating frequency by pressing ‘SHIFT’ and ‘FREQ’ key (Figure 12). ‘AM’
annunciator will flash.
9. Set the frequency of the modulating signal by number keys.
10. Press ‘SHIFT’ and ‘LEVEL’ key to set the modulation depth. The modulation depth is
between 0 and 120%. (Please see Figure 10 for the definition).
Figure 12: Selecting the AM mode
Storing arbitrary waveforms
Once you have set up your arbitrary waveform such as the AM modulated waveform, you can
store them for later use and recall it any time. You can store them up to 4 waveforms. To store a
waveform:
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1. Press the ‘SHIFT’ key.
2. Press ‘STORE’ key.
3. Press the number (from 1 to 4) of the register where you want to store the function.
To recall the waveform:
1. Press ‘RECALL’ key.
2. Press number of the register.
Specifications:
o Frequency characteristics:
•
•
Sine and square: 100µHz - 15 MHz
Triangle and Ramp: 100µHz-100KHz
o Arbitrary waveform:
•
•
•
•
Length: 8 to 16,000 points
Resolution: 12 bits
Sample rate: 40 MSa/sec
Non-volatile memory (arbitrary waveforms): four 16k
o Output: (into 50 Ohm):
Amplitude: 50mVpp - 10 Vpp.
Offset: +/- 5Vpk ac+dc
Output impedance: 50 Ohm
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5. HP 53131A DC-225MHZ 10 Digit Universal Counter
QUICK START
Turn the unit ON; the unit will self test, given Address 03 and will set to Channel 1
(Default).
Connect your leads cables from channel 1 to the circuit under test. See the counter manual for
how to measure frequencies below 100 Hz. The unit will show the exact frequency.
To select another channel, press Frequency button until Freq 2 appears. Connect the circuit
under test to channel 2 and read the measurements from the display of the unit.
New frequency checked will be held for convenience reading when needed.
Also, ratios from freq 1 to 2 or freq 3 can be obtained by pressing frequency button until the
desired ratio appears.
Note: Both channels under test “Must be connected” during ratio reading.
Other readings can be made, such as:
The period T1 to T2 , Rise time 1, Falltime 1, (Positive Width 1, and Negative Width 1),
obtained by pressing the Time and Period button on the front panel until the desired
measurement is found.
Other measurements are possible, such as:
Phase of signal 1 to signal 2 (phase difference between both signals).
Duty cycle: defined as the positive pulse width divided by the period.
Also, Volts Peak: Voltage 1 and Voltage 2 for both signal strength.
See more details below.
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Key Features
•
•
•
•
•
•
225 MHz Basic Bandwidth on both channels
Basic Universal Counter with Time Interval Capability
500 pixels single shot Time Interval resolution
GP-IB and RS232
Fast Continuous-Count measurement technique
Intuilink Software included
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Making Measurements
This quick manual is designed to give you hands-on experience in using the 53131A counter.
Universal Counter can make various measurements.
Required Equipments
1. 53131A Universal Counter
2. Signal Source ( Example: 33220A Function/Arbitrary Waveform Generator)
3. 1 BNC cable
Measuring Common Signals – That’s easy.
1. counter displays the measured frequency around 1 KHz. The frequency is not exactly 1
KHz, it is due to the calibration of both the counter and the function generator.
Notice that a few of the digits shown on the counter are changing.
2. Change the function generator output to a square wave by pressing the [Square]
button.
Observe that the counter's digits are changing less than before. This demonstrates the general fact
that counter works better with fast edge signals (square wave) rather than
slow edge signals (sine wave). This is due to trigger errors that are greater with the
slower edge signals.
Low Frequency Measurements – A little less automatic.
Let’s see what happens if we try to measure a low frequency.
Turn the power off on both the function generator and the counter.
Function Generator Set-up
1. Power the Function Generator on. The default frequency of 1 KHz appears.
2. Change the frequency to 2 Hz. First pressing ‘<’ and ‘>’ locate the digit you want to
change on the generator’s front panel. Second press ‘V’ and ‘Λ’ to change the value to be
2 Hz.
3. Connect the 33220A Output BNC to the 53131A CHANNEL 1 input BNC.
4. Power on the counter. It passes self-test, and displays ---------.
This is a problem sign which is typically caused by either no frequency signal or
an incorrect frequency signal that is not stable. You set a stable 2Hz frequency on
the function generator so…What could be wrong?
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Counter Set-up
Notice the 5 buttons associated with Ch 1 on the Counter.
5. Press the [Trigger Sensitivity] button. The display shows Auto Trg On. The “ON” is
flashing. Whenever a portion of the display is flashing, that means that there are choices
for the flashing element. This element can be changed by pressing one of
the arrow buttons just to the right of the display.
6. Set AUTO TRG: OFF. Auto trigger does not work at frequencies below 100 Hz. The
counter may be set at the wrong trigger voltage.
7. Press [Trigger Sensitivity] again. You can manually set the trigger level. The
generator is outputting a 2 Hz signal symmetric about 0 V (no offset) so an
appropriate trigger level is 0 V.
8. Use the arrow buttons to set the trigger level to 0V. Use the horizontal arrows to
select the digit. When the correct digit is flashing, use the vertical arrows to
increment/decrement the digit’s value.
9. Press the [Enter] button next to the arrows.
10. Press [Run] on the main keyboard panel. You will now get a reading around 2 Hz.
For low frequencies you should also use DC coupling. Here is how:
11. Set DC coupling for Ch 1 (press the [DC/AC] button near Ch 1). You should see a
good solid measure of the 2Hz frequency.
Time Interval Measurements
The counter can do time interval measurements between a signal edge on Ch 1 (start
edge) and an edge of a different signal on Ch 2 (stop edge). The counter can also make
time interval measurements on one signal. The start edge and stop edge are both on one
signal. To do this, the counter is set to put a single signal on both channels at the same
time by selecting “common” signal routing as explained below.
Cycle the power for both the counter and the generator to make sure you are starting
at a known state
Function Generator Set-up
Do not connect the BNC to counter, yet.
Soft keys are buttons just below the display. Their function / labels change depending on where
you are at within the configuration menu. When instructed to press a soft key , look for the label
in the display and press the corresponding button.
1. Turn the functions generator on
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2. Select pulse by press pulse button.
3. Set frequency to 2 KHz.
4. Set amplitude to 1 Vpp. (Press Ampl key, press ‘<’ and ‘>’move flash digit and
set value by pressing ‘V’ and ‘Λ’)
5. Set offset to 0V. (Press Offset key, change the value to be ‘0’).
6. Set pulse frequency to be 2KHz. ( Press Freq key, set value to be 2KHz)
7. Connect BNC to counter Ch1.
Counter Set-up
8. Turn the counter on and wait for it to complete the start-up sequence.
9. Press the [Time and Period] button. T1 to 2 is displayed.
10. Press the Ch 1 [Trigger Sensitivity] button. “AUTO TRG: ON” is displayed.
11. Pressing the [Trigger Sensitivity] button again, it shows “LEVEL: 50 PCT” Make sure to
set “50” by pressing [Enter] before continuing.
12. Press [Trigger Sensitivity] again, “SLOPE: POS.
13. Press again, “SENSTVTY: HI”
14. Press again to see “COMMON 1: OFF”. This means Ch 1 is not connected to Ch 2
internally inside the counter. Note that the “OFF” portion of the displayed message is
flashing. That means it can be changed by pressing one of the arrow buttons to the right
of the display.
15. Set “COMMON 1: ON” Now Ch 1 is connected internally to Ch 2 and they see the same
signal.
16. Press the same buttons (steps 10 through 15) for Ch 2 that you did for Ch 1 to ensure that
the settings are the same for both Channels.
17. Press the [Run] button. The display shows the time interval measurement between
the rising edges of two adjacent pulses in the signal. For a 2 KHz signal this
should be 1/2000 = 500 u sec. You are most likely seeing a time interval
considerably smaller than 500usec.
18. Press the [Gate and Ext Arm] button until it displays “DELAY: NONE” Note that the
“None” portion of the display is flashing.
19. Press an arrow button (to the right of the display) to display “DELAY: TIME”.
20. Press the [Gate & Ext Arm] button to display ‘TIME: .01000 s’.
21. Set the time to 100 usec using the arrow buttons. (set .00010s by using the horizontal
arrows to move digits, use the vertical arrows to increment/decrement numbers)
22. Press [Enter] located by the arrow buttons.
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Note: You must press [Enter], otherwise, your setting will be lost.
23. Press [Run]. You should see a display of 500 usec.
Slowing Down the Display by Using Stats
Counter Set-up
1. Press the [State] button.
2. Set SHOW MEAS to display SHOW MEAN by pressing the arrow key.
3. Press [Stats] again and set N to 02
4. Press [Enter]
5. Press [Run]
Notice that the display has slowed down and is easier to read.
Totalize Measurements
The counter’s totalize feature simply means counting triggered edges. For instance, we
now have a signal from the 33220A that is a pulse occurring at a 2 kHz rate. So, if we
were to totalize this signal for 1 second, the total shown should be 2000 ±1 count.
Counter Set-up
1. Press the [Other Meas] button once to display TOTALIZE 1. If you wait a moment, you
will see the display show 200. Now press the [Gate & ExtArm] button and see GATE:
TIME. Notice that TIME is flashing. Check the available choices with the arrow buttons.
The choices are TIME, AUTO, and EXTERNAL.
2. Set the flashing field to TIME.
3. Press the [Gate & ExtArm] button again to display .100 seconds.
4. Use the arrow buttons to set the gate time to 1 second.
5. Press [Enter].
6. Press [Run]. The display now shows 2000. That is, the counter is counting 2000
pulses in 1 second on channel 1. CAUTION here. The 1-second gate that you set
is not very accurate. Instead of deriving the 1-second gate from the precision
clock time base, it is derived from the u-processor clock. Why the count that they
expected is not being displayed? The reason is, most likely because of an error in
the time gate, not the count mechanism itself. To make really accurate time gated
TOTALIZE measurements you must supply a precision time length pulse to the
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external gate.
7. Press [Gate & ExtArm] twice to display GATE: TIME (with time flashing).
8. Set GATE: AUTO using the arrow buttons.
9. Press [Run]. The counter counts and counts in a continuous mode until you Press the
[Stop/Single] button. Pressing [Run] again resets the totalizer back to zero. There is no
way to just pause the Totalize function; you must stop it and that automatically resets it.
The last choice, External, allows you to set a positive or negative going edge as the start
for TOTALIZE. It also allows you to set a positive or negative going edge as the stop for
TOTALIZE.
Limit Testing
It is possible to do limit testing with the 53131A counters. For example, you may want to know
whenever a measured frequency goes outside a predefined upper limit or lower limit.
Cycle the power on the counter and the function generator to ensure a known starting
point.
Function Generator Set-up
Turn the function generator on. It will be set to a default 1 KHz sine wave with an
amplitude of 100 mVpp.
Counter Set-up
1. Turn the counter on. After the start up sequence, the counter will read approximately 1
KHz.
2. Press the [Limit Modes] button. Note that the LIM TEST: OFF is displayed.
3. Press an arrow button to turn LIM TEST: ON.
4. Press the [Limit Modes] button twice to display SHOW: NUMBER.
5. Press the [Uppr & Lower] button and set the upper limit of 1010 Hz using the arrow
buttons.
6. Press [Enter].
7. Press the [Uppr & Lower] button again and set the lower limit to 990 Hz.
8. Press [Enter].
9. Press [Run]. The counter should be displaying a measurement of about 1 kHz.
10. Change the frequency of the function generator to frequencies above and below the
limits. (Use the horizontal arrow to move digits, turn the knob to
Increment / decrement frequency).
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Note: The Limit light comes on on the counter display when the frequency is above or
below the limit.
Limit test graphic mode
There is a convenient and unique way to display in and out of limit conditions using these
counters.
1. Press the [Limit Modes] button until SHOW: NUMBER is displayed.
2. Press the arrow buttons to display SHOW: GRAPH.
3. Press [Run]. Notice that an asterisk and two colons are shown in the counter’s
display.
4. Change the generator’s frequency slowly so that it exceeds both the lower and upper
frequency limits. The asterisk represents the current frequency with respect to the limits
(two colons).
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6. Function/Arbitrary Waveform Generator
HP33220A 20 MHz
Specification
HP 33220A function/arbitrary waveform generator uses direct digital synthesis (DDS) techniques
to create stable, low-distortion output signals and provides easy access to standard sine, square,
ramp, triangle, pulse waveforms, and also, you can create custom waveforms using the 50
MSa/s, 14 bit, 64 K-point arbitrary waveform function. It supports variable-edge pulse function
and create PWM. The 33220A includes USB, LAN and GPIB interfaces.
•
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20 MHz sine and square waveforms
Ramp, triangle, pulse, noise, and DC waveforms
14-bit, 50 MSa/s, 64 K-point arbitrary waveforms
AM, FM, PM, FSK, and PWM modulation types
Linear & logarithmic sweeps and burst operation modes
Graph mode for visual verification of signal settings
USB, GPIB and LAN interfaces included
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The Front Panel Display at a Glance
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Front-Panel Number Entry
To Set the Output Frequency
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To Set Output Amplitude
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