Elenco Electronics AK-510 Instruction manual

MOTION DETECTOR KIT
MODEL AK-510
Assembly and Instruction Manual
Elenco Electronics, Inc.
®
Copyright © 2006, 1994 by Elenco® Electronics, Inc. All rights reserved.
Revised 2006
REV-N
No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.
753010
PARTS LIST
If you are a student, and any parts are missing or damaged, please see instructor or bookstore.
If you purchased this kit from a distributor, catalog, etc., please contact Elenco® Electronics (address/phone/email is at the back of this manual) for additional assistance, if needed. DO NOT contact your place of purchase
as they will not be able to help you.
RESISTORS
Qty.
1
1
1
4
1
1
2
1
1
1
1
1
Symbol
R16
R15
R5
R1, 2, 8, 9
R3
R14
R11, R12
R13
R10
R6
R7
R4
Description
300Ω 5% 1/4W
5.6kΩ 5% 1/4W
39kΩ 5% 1/4W
47kΩ 5% 1/4W
75kΩ 5% 1/4W
270kΩ 5% 1/4W
300kΩ 5% 1/4W
470kΩ 5% 1/4W
510kΩ 5% 1/4W
620kΩ 5% 1/4W
1.2MΩ 5% 1/4W
1.6MΩ 5% 1/4W
Color Code
orange-black-brown-gold
green-blue-red-gold
orange-white-orange-gold
yellow-violet-orange-gold
violet-green-orange-gold
red-violet-yellow-gold
orange-black-yellow-gold
yellow-violet-yellow-gold
green-brown-yellow-gold
blue-red-yellow-gold
brown-red-green-gold
brown-blue-green-gold
Part #
133000
145600
153900
154700
157500
162700
163000
164700
165100
166200
171200
171600
CAPACITORS
Qty.
1
1
2
2
2
Symbol
C8
C9
C2, C3
C4, C5
C1, C6
Value
500pF (501)
.01µF (103)
10µF 25V
22µF 25V
100µF 16V
Description
Discap
Discap
Electrolytic (Lytic)
Electrolytic (Lytic)
Electrolytic (Lytic)
Qty.
1
1
1
1
1
1
Symbol
D1
Q1
IC1
IC2
IC3
S1
Value
1N4148
MPSA18
LM324
HT2812G
78L05
LHI-954 / KDS245
Qty.
1
1
1
1
1
1
1
1
Description
PC Board
Speaker w/ Wires
Switch Key
SW1 - Slide Switch
Battery Snap
Front Cover
Back Cover
Mounting Bracket
Part #
225080
241031
271045
272245
281044
SEMICONDUCTORS
Description
Diode
Transistor NPN
Integrated Circuit
Integrated Circuit
Integrated Circuit
Infrared Detector
Part #
314148
320018
330324
332812
338L05
350954
MISCELLANEOUS
Qty.
1
2
2
2
1
1
1
Part #
517019
520813
540105
541007
590098
623104
623202
626004
Resistor
PARTS
IDENTIFICATION
Capacitor
Description
Battery Cover
Screw #4 x 1/4”
Screw #4 x 5/8”
Washer #4 (Fiber)
Socket IC 8-Pin
Socket IC 14-Pin
Solder Tube
Battery Snap
Diode
Transistor
Integrated Circuit
Integrated
Circuit
Infrared Detector
Note: The text printed on
the
LHI-954
Infrared
Detector is the date code.
Socket
Electrolytic Discap
-1-
Part #
626005
642430
643450
645404
664008
664014
9ST4
Switch
Speaker
IDENTIFYING RESISTOR VALUES
Use the following information as a guide in properly identifying the value of resistors.
BAND 1
1st Digit
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
Multiplier
BAND 2
2nd Digit
Digit
0
1
2
3
4
5
6
7
8
9
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
Resistance
Tolerance
Color
Multiplier
Black
1
Brown
10
Red
100
Orange
1,000
Yellow
10,000
Green
100,000
Blue
1,000,000
Silver
0.01
Gold
0.1
Digit
0
1
2
3
4
5
6
7
8
9
Color
Silver
Gold
Brown
Red
Orange
Green
Blue
Violet
Tolerance
+10%
+5%
+1%
+2%
+3%
+.5%
+.25%
+.1%
BANDS
1
2
Multiplier
Tolerance
IDENTIFYING CAPACITOR VALUES
Capacitors will be identified by their capacitance value in pF (picofarads), nF (nanofarads), or µF (microfarads). Most
capacitors will have their actual value printed on them. Some capacitors may have their value printed in the following
manner. The maximum operating voltage may also be printed on the capacitor.
Multiplier
For the No.
0
1
2
3
Multiply By
1
10
100
1k
4
5
8
9
10k 100k .01
0.1
Note: The letter “R” may be used at times
to signify a decimal point; as in 3R3 = 3.3
10µF 16V
First Digit
Second Digit
Multiplier
103K
Tolerance
100V
The letter M indicates a tolerance of +20%
The letter K indicates a tolerance of +10%
The letter J indicates a tolerance of +5%
Maximum Working Voltage
The value is 10 x 1,000 = 10,000pF or .01µF 100V
METRIC UNITS AND CONVERSIONS
Abbreviation
p
n
µ
m
–
k
M
Means
Pico
nano
micro
milli
unit
kilo
mega
Multiply Unit By
.000000000001
.000000001
.000001
.001
1
1,000
1,000,000
1. 1,000 pico units
Or
10-12
10-9
10-6
10-3
100
103
106
= 1 nano unit
2. 1,000 nano units = 1 micro unit
3. 1,000 micro units = 1 milli unit
-2-
4. 1,000 milli units
= 1 unit
5. 1,000 units
= 1 kilo unit
6. 1,000 kilo units
= 1 mega unit
CONSTRUCTION
Introduction
The most important factor in assembling your AK-510 Motion Detector Kit is good soldering techniques. Using
the proper soldering iron is of prime importance. A small pencil type soldering iron of 25 - 40 watts is
recommended. The tip of the iron must be kept clean at all times and well tinned.
Safety Procedures
• Wear eye protection when soldering.
• Locate soldering iron in an area where you do not have to go around it or reach over it.
• Do not hold solder in your mouth. Solder contains lead and is a toxic substance. Wash your hands
thoroughly after handling solder.
• Be sure that there is adequate ventilation present.
Assemble Components
In all of the following assembly steps, the components must be installed on the top side of the PC board unless
otherwise indicated. The top legend shows where each component goes. The leads pass through the
corresponding holes in the board and are soldered on the foil side.
Use only rosin core solder of 63/37 alloy.
DO NOT USE ACID CORE SOLDER!
What Good Soldering Looks Like
Types of Poor Soldering Connections
A good solder connection should be bright, shiny,
smooth, and uniformly flowed over all surfaces.
1.
Solder all components from
the copper foil side only.
Push the soldering iron tip
against both the lead and
the circuit board foil.
1. Insufficient heat - the
solder will not flow onto the
lead as shown.
Soldering Iron
Component Lead
Foil
Soldering iron positioned
incorrectly.
Circuit Board
2.
3.
4.
Apply a small amount of
solder to the iron tip. This
allows the heat to leave the
iron and onto the foil.
Immediately apply solder to
the opposite side of the
connection, away from the
iron.
Allow the heated
component and the circuit
foil to melt the solder.
Allow the solder to flow
around the connection.
Then, remove the solder
and the iron and let the
The
connection cool.
solder should have flowed
smoothly and not lump
around the wire lead.
Rosin
2. Insufficient solder - let the
solder flow over the
connection until it is
covered. Use just enough
the
solder
to
cover
connection.
Soldering Iron
Solder
Foil
Solder
Gap
Component Lead
Solder
3. Excessive solder - could
make connections that you
did not intend to between
adjacent foil areas or
terminals.
Soldering Iron
Solder
Foil
4. Solder bridges - occur
when solder runs between
circuit paths and creates a
short circuit. This is usually
caused by using too much
solder.
To correct this,
simply drag your soldering
iron across the solder
bridge as shown.
Here is what a good solder
connection looks like.
-3-
Soldering Iron
Foil
Drag
INTRODUCTION
The AK-510 is an infrared motion detector kit. The objective of the kit is to teach the operations of the four
sections that make up the kit. The four sections are shown in the block diagram below.
POWER
SUPPLY
OPERATIONAL
AMPLIFIERS
FILTERS
INFRARED
DETECTOR
TONE
GENERATOR
There are many applications for the use of the detector. The most common is in the alarm system industry.
Some of the new applications are automatic door openers, light switches in hallways, stairways and areas that
increase safety for the public. Further applications can be seen in automatic production lines, switching of
sanitary facilities, monitors and intercoms. With the ease of installation and the low suspectibility to interference
from other forms of radiation, such as heaters or windows, the IR detectors are ideal devices.
POWER SUPPLY (see page 16)
A 9 volt battery is used to supply the DC voltage to
the circuit. The battery voltage must be regulated
(held as close as possible) to 5 volts. This is done by
circuits called voltage regulators.
In order to see how this is accomplished, let’s
consider the analogy of a water tower. Voltage in
electronics can be compared to water pressure in
a water system. When water is pumped into a
water tower, the pressure at the bottom of the
tower can be quite high. In order to keep a
constant pressure in the water pipes that go to the
houses, the pressure must be lowered and held
constant.
Consider the system shown in Figure 1. As
people draw water into their homes, the pressure
on the low pressure side of the valve drops. The
spring pulls the valve arm inside the pipe up along
opening the valve and allowing more water into
the pipe. As the pressure on the low pressure
side increases, it pushes the valve arm inside the
pipe down closing the valve and stretching the
spring. By increasing the spring pressure on the
arm, the pressure on the low side will have to
increase to close the valve. The force or pressure
of the spring, therefore sets the value of the
pressure on the low pressure side of the system.
The force of the spring is called the reference
pressure.
Figure 1
Voltage in electronics is the analogy to pressure in water pipes. A voltage greater than 7V is applied to the
input of high voltage side of the regulator. A fixed reference voltage inside the regulator will set the low voltage
output at 5 volts +5%. This is accomplished in a manner very similar to our water tower analogy. The output
voltage is filtered or made smooth (no ripples) by capacitor C6 (100µF).
-4-
INFRARED DETECTOR
when it strikes a solid surface. All solid bodies at a
temperature above absolute zero emit thermal
radiation. As a body’s temperature rises, the shorter
the resulting wavelengths become. The human
body’s maximum thermal radiation is between 9µm
and 10µm in the infrared stage. Motion can be
detected by special elements which are highly
sensitive in the infrared range. Such devices are
called Pyroelectric Infrared Detectors.
Infrared light was first discovered back in 1801 by W.
Herschel. Infrared is a form of radiated energy in
which the wavelength is longer than the wavelength
of visible light. A wavelength can best be understood
by the physical analogy shown in Figure 2.
PYROELECTRIC EFFECT
When certain materials change temperature, they
produce electricity. A Pyroelectric crystal is an
example of such a material. If a Pyroelectric crystal
has been at the same temperature for a period of
time, there will be no voltage across it’s electrodes.
When the crystal temperature changes, a voltage is
produced at the electrodes of the crystal element.
This type of crystal is used in this motion detector kit
inside the infrared (IR) detector.
INTERNAL DESIGN
Figure 2
The IR detector contains two crystals connected
with each other in opposite polarity and with a 1
millimeter (mm) optical spacing. These two crystals
are located behind an optical filter or lens (see
Figure 3). The output power of the crystals is very
low. A special device called the Field Effect
Transistor (FET) is used to increase the power
output. The FET can be compared to water pipes as
shown in Figure 4. The center of a small section of
pipe is made of thin, flexible rubber surrounded by
water from a third pipe called the gate. When
pressure (voltage) is applied to the gate, the rubber
tube closes and pinches off the flow of water
(current) from source to drain. In a similar manner,
as infrared radiation is detected, the crystals
produce a voltage at the gate of the FET.
If you were standing at the beach watching the
waves come in to shore, you would be able to see
the peaks of each wave as they approached. If you
could measure the distance from one peak to the
next, you would know the “Wavelength” of those
waves. We will use the eleventh letter of the Greek
alphabet “λ” (lambda) to represent the distance
between valleys to determine the length of the wave
(see Figure 2). A wavelength can be defined as the
distance between any two exactly equal points on
identically repeating waves.
What would happen if we reduced the distance
between the peaks to 1/2 the original distance.
Would it not be true, the peaks would strike the
shore twice as often as before? The frequency of
the peaks reaching the shore would be twice that of
the longer wave. For people who like big words, we
would say “Frequency is inversely proportional to
the wavelength”. In simple words, “If the wavelength
goes up, the frequency goes down and if the
wavelength goes down, the frequency goes up”.
The mathematics of waves applies also to the
radiation of light. It is common practice, therefore, to
talk about light as lightwaves. The wavelength of
infrared light ranges from .78 micrometers (µm) to
100 (µm). A micrometer is one millionth of a meter.
Optical Filter
Infrared Rays
Gate
Drain
Crystals
Source
Resistor
Ground
Dual Element Detector Scheme
Infrared can be thought of as heat radiation
because the radiant energy is transformed into heat
Figure 3
-5-
This causes a change in current from the drain to
source. Very little power is required at the gate to
control the larger current flow from source to drain.
The benefits of this type of detector are low radio
interference, low noise, specially suited response. The
IR detector is sealed in a metal housing to prevent
electromagnetic interference and to keep them clean.
Source
Gate
FIELD OF VIEW
FET Transistor
Detectors are available with different fields of
view, depending on the application.
The
maximum distance and total angle of view are
important specifications needed in choosing a
motion detector. The LHI-954 field of view is
shown in Figure 5.
Drain
Figure 4
46O
46O
56O
CIRCUIT DESCRIPTION (see page 16)
Horizontal
The IR Section contains only a few components,
R1, R2, C1 and the PIR sensor. As motion is
detected, the IR detector will produce a voltage at
the gate of the FET allowing current to flow from the
drain to source, causing the voltage at the input of
U1 (pin 13) to change, thus changing the output at
pin 14. Resistors R1 and R2 limit the amount of
current flow through the FET.
Vertical
56O
Figure 5
OPERATIONAL AMPLIFIERS / FILTERS
Obviously, in the real world these conditions can
never be met, but for mathematical purposes they
are assumed in designing electronic circuits with
op-amps.
An amplifier is a device that uses a small amount
of power to control a larger amount of power. Just
like a small amount of power on the valve arm of
Figure 1 controlled the water pressure in the pipes
going to the houses. The amplifier does not create
power (it was already there in the water tower) but
it controls the power from a source.
The op-amp has two input terminals, inverting input
(–) and non-inverting input (+), and one output
terminal. Figure 6 shows the standard op-amp
symbol. The two input terminals are labeled 2 and
3, and the output is 1. Most op-amps operate with
two DC power supplies, +VCC and –VEE connect to
pins 11 and 4 respectively. Since a single power
supply is used in the kit, –VEE (pin 4) is tied to
ground. The op-amp multiplies the difference
between the voltage signals applied at its two input
terminals (V3-V2) times the gain of the amplifier (A).
A x (V3-V2) appears at the output terminal as
shown in Figure 7.
In electronics, amplifiers are composed of devices
called transistors, resistors, and capacitors. The
number of these components used and the way
they are assembled determines the characteristics
of the amplifier. An amplifier that can perform many
mathematical operations such as adding,
subtracting, or multiplying voltages is called an
Operational Amplifier or Op-Amp.
The characteristics of an ideal op-amp are the
following:
A. infinite voltage gain (no voltage at all on the
input controls, large voltage on the output).
B. infinite bandwidth (no matter how fast the input
changes, the output will change just as fast).
C. infinite input impedance (no power required at
input to change output).
D. zero output impedance (the output can deliver
an infinite amount of power).
Inverting
Input
+Vcc
2
2
4
Output
A (V3 - V2)
3
V3
–VEE
1
V2
Output
Figure 6
-6-
11
1
3
NonInverting
Input
+Vcc
11
4
–VEE
Figure 7
NEGATIVE FEEDBACK
VOLTAGE COMPARATOR
The open loop gain (or maximum gain) of a typical opamp is very high (usually greater than 100,000),
enabling a very small input voltage to drive the opamp output to it’s extremes.
To prevent this, a
resistor is connected between the output and
inverting input terminals allowing a portion of the
output signal to be brought back and cancel part of
the input (Figure 8). This process is called Negative
Feedback. The signal being fed back is out of phase
with the input and thus subtracts from the input signal.
If the resistor was connected between the noninverting input and output terminals, it would be called
Positive Feedback. The closed loop gain (or gain
after feedback) from the input Vi to the output terminal
depends on the ratio of R2 to R1.
Operational amplifiers can be used to compare the
amplitude of one voltage with another. As a
comparator, its function is to determine when an
input voltage exceeds a certain level. When used as
a comparator, the op-amp is used without feedback
and at maximum gain. One input is set to a
reference voltage and the other tied to the input
voltage.
R2
R1
2
1
Vi
Vo
3
Vo = –(R2/R1) Vi
For example, if R2 = 100 and R1 = 10, the gain (G) =
R2/R1 = 100/10 = 10. Thus, the output voltage Vo
would be equal to –10(Vi). The (–) sign indicates that
the output and input voltages are of opposite polarity.
OR
Vo = –G Vi
Figure 8
FILTERS
LOW PASS FILTER
HIGH PASS FILTER
A low pass filter attenuates (decreases) all signals
above a certain frequency and passes frequencies
below that frequency. An example of a low pass filter
is a simple RC network as shown in Figure 9. Low
frequencies are passed unharmed. As the frequency
rises the output is reduced (see Figure 10).
The high pass filter attenuates frequencies below a
certain frequency and passes frequencies above that
frequency. An example of a high pass filter is a simple
RC network as shown in Figure 11. Low frequencies
are reduced when passed through the filter while high
are passed unharmed (see Figure 12).
Figure 9
Figure 11
Figure 10
Figure 12
-7-
BAND PASS FILTER
It is the ratio of the center (or Resonant) frequency to
the bandwidth (Q = fr/BW). A filter with a higher value
of Q has a narrower bandwidth, thus passing fewer
frequencies than one with a lower value. Bandpass
filters can be classified as either a narrow-band (Q >
10) or a wide-band (Q < 10).
The combination of a low and high pass filter create
what is called a Band Pass Filter. The frequencies
passed by each filter overlap and create a bandwidth
(range), passing all signals within the bandwidth and
reducing all others. Figure 13 illustrates the general
band-pass response curve. A critical frequency is
defined as the point where the voltage is reduced to
.707 (the square root of ½ is used because it
represents the point where power has been reduced
to ½). The bandwidth can be defined as the
difference between the upper critical frequency (fC2)
and the lower critical frequency fC1 (BW = fC2 - fC1). The
selectivity (or Quality) of a band-pass filter is
expressed as the “Q” of the filter.
CIRCUIT DESCRIPTION (See page 16)
The op-amp IC1D shapes the frequency response
to amplify those frequencies produced when motion
is detected and rejects all others, such as those due
to noise or slow temperature changes. Frequencies
above 20Hz and below 1Hz are beyond the
bandwidth of the circuit and thus are rejected. The
output at pin 14 is about 1.6V when no motion is
detected. As motion is detected, the voltage at the
output will change and trigger either IC1C or IC1B.
Gain
The op-amps IC1A, IC1B and IC1C are configured
as voltage comparators. In the ready state, the
output of IC1A is high and IC1B and IC1C are low.
When IC1D outputs a voltage lower than 1.41V, it will
force pin 2 of IC1 high. When IC1D outputs a
voltage higher than 1.67V, it forces pin 8 and pin 2 of
IC1 to go high. A high in with one of these cases
causes the output to go low and allows C9 to
discharge through IC1A. The discharging of C9 will
pull pin 6 of IC2 low and trigger the sound generator.
100%
70.7%
BW
f
fc1
fr
fc2
Figure 13
SOUND GENERATOR
CIRCUIT DESCRIPTION (see page 16)
The circuit uses the single sound generator HT2812G
IC. The HT2812G is a CMOS LSI chip designed for
use in sound effects products. Figure 14 shows the
internal design of the IC.
Osc1
Osc2
Key
Oscillator
Divider
Speed
Generator
Key
Tone
Generator
Selector
Input
Logic
Noise
Generator
As the Key Input is brought low, the Oscillator, Speed
Generator, Tone Generator, Noise Generator and
Envelope Sections are all enabled. The Oscillator
Section begins to oscillate at a frequency determined
by the voltage across pins 7 and 8. This frequency is
then divided down and applied to the Speed
Generator. The Speed Generator controls the
frequency of the output as it is applied to the output
driver. The output consists of 15 pulses. Appling the
pulses to the base of transistor Q1, turns it on and off
rapidly, causing the speaker to sound. You can select
between a high and a low tone using switch SW1.
Output
and
Output
Envelope
Driver
Output
Circuit
Env
Figure 14
Key
Output
Figure 15
-8-
ASSEMBLE COMPONENTS TO THE PC BOARD
R2 - 47kΩ 5% 1/4W Resistor
(yellow-violet-orange-gold)
C2 - 10µF 25V Electrolytic
(see Figure D)
C4 - 22µF 25V Electrolytic
(see Figure D)
R5 - 39kΩ 5% 1/4W Resistor
(orange-white-orange-gold)
R3 - 75kΩ 5% 1/4W Resistor
(violet-green-orange-gold)
C8 - 500pF (501) Discap
D1 - 1N4148 Diode
(see Figure A)
R4 - 1.6MΩ 5% 1/4W Resistor
(brown-blue-green-gold)
(See Note)
R6 - 620kΩ 5% 1/4W Resistor
(blue-red-yellow-gold)
(See Note)
R9 - 47kΩ 5% 1/4W Resistor
(yellow-violet-orange-gold)
14-pin IC Socket
IC1 - LM324 Integrated Circuit
(see Figure C)
R12 - 300kΩ 5% 1/4W Resistor
(orange-black-yellow-gold)
R11 - 300kΩ 5% 1/4W Resistor
(orange-black-yellow-gold)
Note: C7 is not used in this kit.
R10 - 510kΩ 5% 1/4W Resistor
(green-brown-yellow-gold)
C9 - .01µF (103) Discap
C6 - 100µF 16V Electrolytic
(see Figure D)
IC3 - 78L05 Integrated Circuit
(see Figure B)
D2 - Use a Jumper Wire in
place of the diode.
C5 - 22µF 25V Electrolytic
(see Figure D)
Figure A
Figure C
Figure D
Align the socket notch (if any) with the
notch marked on the PC board.
Solder the socket to the PC board.
Insert the IC into the socket with the
notch as shown below.
These capacitors are
polarized.
Be sure to
mount them with the “+”
lead in the correct hole as
marked on the PC board.
Figure B
Flat
Notch
Band
Diodes have polarity. Be sure to mount them
with the band going in the same direction as
marked on the PC board.
Mount the device with the flat
side in the same direction as
shown on the PC board.
Solder and cut off the excess
leads.
-9-
+
ASSEMBLE COMPONENTS (CONTINUED)
Jumper Wire (see Figure E)
C1 - 100µF 16V Electrolytic
(see Figure D)
R1 - 47kΩ 5% 1/4W Resistor
(yellow-violet-orange-gold)
C3 - 10µF 25V Electrolytic
(see Figure D)
R8 - 47kΩ 5% 1/4W Resistor
(yellow-violet-orange-gold)
R7 - 1.2MΩ 5% 1/4W Resistor
(brown-red-green-gold)
S1 - LHI-954 Infrared Detector
Mount with tab in the same direction as
marked on the PC board (see note below).
R14 - 270kΩ 5% 1/4W Res.
(red-violet-yellow-gold)
R13 - 470kΩ 5% 1/4W Resistor
(yellow-violet-yellow-gold)
SW1 - Slide Switch
R16 - 300Ω 5% 1/4W Resistor
(orange-black-brown-gold)
8-pin IC Socket
IC2 - HT2812G Integrated Circuit
(see Figure C)
Q1 - MPSA18 Transistor
(see Figure B)
–
R15 - 5.6kΩ 5% 1/4W Resistor
(green-blue-red-gold)
Black
Red
+
Speaker Wires - Solder the
two wires to the PC board
marked SPK +, –.
Inside Pads
Note: If wires need resoldering;
Outside Pads
1. First apply a small amount of
solder to the outside pad.
2. Solder the speaker wire to
the outside pads.
CAUTION:
The internal
speaker wires are soldered to
the inside pads. DO NOT
unsolder these wires.
B1 - Battery Snap
Identify the battery snap B1. Insert the red and black wires
through the hole from the copper side of the PC board.
Insert the red wire into the (+) positive hole and the black
wire into the (–) negative hole as shown above.
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Note: The text printed
on
the
LHI-954
Infrared Detector is
the date code.
Figure E
Use a discarded lead for
a jumper wire.
FINAL ASSEMBLY
Step 1
Place the speaker into the front case as
shown in Figure 16. Use two #4 x 1/4”
screws and two #4 washers to secure it
into place.
#4 x 1/4” Screws
#4 Washers
Figure 16
Step 2
Push the switch key onto the switch as
shown in Figure 17. Make sure that the
key-switch is sitting properly on the
switch.
Switch Key
Figure 17
Step 3
Place the PC board into the front case
as shown in Figure 18. Attach the back
case to the front case with two #4 x 5/8”
screws. Note: There is a small groove
that the key switch fits into.
Figure 18
-11-
Step 4
Attach a 9V battery to the battery snap
and place it into the case. Snap the
battery cover into the back case as
shown in Figure 19.
Battery Cover
Figure 19
Step 5
Place the unit onto a table and turn it on.
Move to one side of the detector so that
you are out of the field of view of the
detector. Walk in front of the detector and
a tone will sound from the speaker. The
unit is now ready for use.
Note: When the switch is in the OFF position, it disconnects the voltage to the
sound generator IC only. The rest of the circuit is still operating. The battery will
run down if it is left in the OFF position. To increase battery life, remove the
battery if you intend to leave the unit in the OFF position for long periods of time.
INSTALLATION
The detector can be either placed on a
flat surface or mounted onto a wall.
Adjust the angle lever to the open
position (see Figure 20). Align the two
taps on the bracket with the two grooves
on the case. Adjust for the desired angle
and move the angle lever to the lock
position.
Angle Lever
Open
Angle Lever
Closed
Plastic Bracket
Figure 20
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TROUBLESHOOTING GUIDE
The values given below are approximate.
POWER SUPPLY
1. Measure the voltage at IC3. Pin 3 = 9V, Pin 1 = 4.75 - 5.25V
A. Check soldering around IC3 and C6.
B. Check for short to GND from pins 2 and 3.
C. If no shorts are present, IC3 may be defective.
INFRARED DETECTOR
2. Measure the voltages at points:
A = 5V
B = 4.25V
C = .700V
A. Voltage at point A incorrect:
1. Check R1.
2. Check for a short between point A and GND.
B. Voltage at point B incorrect:
1. Check R1, C1 for correct value.
2. Check for a short between point B and GND.
C. Voltage at point C incorrect:
1. Check R2, C2 for correct value.
2. Check for a short between point B and GND.
C
B
A
OPERATIONAL AMPLIFIERS
3. Measure the voltages at IC1 while the unit is at standby.
Pin
1
2
3
4
5
6
7
Voltage
3.80V
–
1.40V
5.00V
1.40V
1.60V
–
Pin
8
9
10
11
12
13
14
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Voltage
–
1.62V
1.60V
–
1.52V
1.55V
1.50 - 1.60V
4. Measure the voltages at IC1 when activated.
Pin
1
7
8
14
Voltage
0 - 3.8V
0 - 3.8V
0 - 3.8V
1.5 - 3.8V
A. Incorrect voltage readings:
1. Check resistors R3 - R12 for correct value.
2. Check diode D1 polarity.
3. Check C3 and C4 polarity.
4. IC1 may be defective.
SOUND GENERATOR
Measure the voltage at the following pins on U2, as listed in the chart below.
U2
Pin
3
5
6
7
Voltage
No Sound
0
5V
5V
0V
Voltage
Sound
0 - 4V
5V
.735V
A. No voltage at pin 3:
1. Check R13, R14, SW1 and C5.
B. No 5V at pin 5:
1. Check SW1 solder connection.
2. No 5V at pin 6.
3. Check C9.
C. Outputs two short tones:
1. Check C5.
Q1
Pin
E
B
C
Voltage
No Sound
0
0V
9V
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Voltage
Sound
0V
.355V
7 - 9V
Q1
EBC
QUIZ
1. The 9V battery supplies a . . .
A. positive AC voltage.
B. DC voltage.
C. AC voltage.
D. rectified DC voltage.
2. A human’s maximum thermal radiation is between . . .
A. 3 and 5µm.
B. 9 and 13µm.
C. 10 and 20µm.
D. 9 and 10µm.
3. As temperature changes, the pyroelectric crystals generate . . .
A. white light.
B. infrared light.
C. heat.
D. a voltage.
4. A wavelength is the distance between two points having . . .
A. opposite phases.
B. two different phases.
C. the same phase, but different voltages.
D. the same phase and voltage.
5. Infrared can be thought of as heat radiation because the . . .
A. electrical energy is transformed into heat.
B. radiant energy is transformed into heat.
C. mechanical energy is transformed into heat.
D. solar energy is transformed into heat.
6. What are the two inputs called in an op-amp?
A. non-inverting and inverting.
B. V1 and V2.
C. VEE and VCC.
D. gates.
7. A high pass filter attenuates all signals . . .
A. between two frequencies.
B. below the critical frequency.
C. above the critical frequency.
D. with high amplitudes.
8. The formula for the closed loop gain is . . .
A. (R2 x R1)Vo
B. (R1/R2)Vi
C. (R2/R1)Vo
D. -(R2/R1)Vi
9. A low pass filter attenuates all signals . . .
A. between two frequencies.
B. below the critical frequency.
C. above the critical frequency.
D. with low amplitudes.
10. A filter with a high value in Q has a . . .
A. wide bandwidth.
B. narrow bandwidth.
C. long bandwidth.
D. attenuates less frequencies.
Answers: 1. B, 2. D, 3. D, 4. D, 5. B, 6. A, 7. B, 8. D, 9. C, 10. B
-15-
SCHEMATIC DIAGRAM
-16-
SPECIFICATIONS
Power
Detection Distance
• 9V DC battery
• 10 feet max., best at 1’ to 6’
Current
Output Sound
• Operating 60mA (average)
• Standby Typical less than 4mA
Detection
• High frequency / Low frequency tone (15-pulse siren)
• 85 - 90dB peak
Operating Range
• Pyroelectric Infrared Sensor.
• –10 to +50OC
GLOSSARY OF TERMS
Amplify
To enlarge or increase.
Amplitude
The greatest difference above a reference, usually zero.
Analogy
Likeness or resemblance in relations of different objects.
Attenuate
To weaken or reduce.
Bandwidth
The group or number of frequencies unaffected by a filter.
Battery
A device that generates an electric current through a chemical reaction.
Capacitors
Devices that store electronic charges.
Circuit
The entire line through which electric current may pass.
Closed Loop Gain
Gain after feedback.
Comparator
An electronic device to detect voltage differences.
Critical Frequency
The frequency at which power in a filter falls to half.
Crystals
An inorganic body with plane surfaces in a geometrical form.
Current
The flow of electrons.
Detector
A device that changes signals into useful information.
Electromagnetic
A radiated wave having both electric and magnetic properties.
FET
Field Effect Transistor.
Filter
A device used to nullify certain waves without altering others.
Frequency
The repeated occurance of anything at brief intervals.
Gain
To increase or make larger.
Gate
A device used to allow or restrict passage.
Generator
A device that transforms energy into electric power or signals.
Impedance
A device’s resistance to the passage of electrical current.
Infrared Light
Rays past the red end of the visible light spectrum.
IR Detector
A device that senses the presence of infrared light.
Kit
A collection of equipment or components.
Lambda
The eleventh letter of the Greek Alphabet.
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Low Pass Filter
Decreases all signals above a certain frequency and passes frequencies below
that frequency.
Negative Feedback
To allow a portion of the output signal to be brought back and cancel part of the
input.
Noise
A random, persistent disturbance of a signal.
Open Loop Gain
The maximum gain available without feedback.
Oscillator
A device used to vary between alternate extremes (varies from high to low).
Peak
The top of a wave or mountain.
Polarity
The division of two opposites.
Power
Electrical energy; strength, force, or might.
Pyroelectric Effect
When certain metals change temperature, they produce energy.
RC Network
An assembly of resistors and capacitors.
Reference Voltage
Level of electronic element used for providing resistance in a circuit.
Resistor
An electric element used for providing resistance in a circuit.
Response Curve
The shape of an output produced by a circuit.
Solder
An alloy (mixture) of tin and lead used in the melted state to join or repair metal
parts.
Transistor
A three-terminal semiconductor device used for amplification, switching, and
detection.
Valve
A mechanical device that regulates the flow of gases, liquids, or loose materials by
blocking and uncovering openings.
Voltage
An electromotive force.
Wavelength
The distance in a periodic wave between 2 points of corresponding phases.\
For further information on infrared light and waves . . .
The Invisible World of the Infrared
By Jack R. White
New York: Dodd, Mead, © 1984
124 p.; ill.
Waves and Vibrations
By Brian Knapp
Danbury, CT: Grolier, © 1994
48 p.; ill.
-18-
Elenco® Electronics, Inc.
150 Carpenter Avenue
Wheeling, IL 60090
(847) 541-3800
Web site: www.elenco.com
e-mail: elenco@elenco.com