MOTION DETECTOR KIT
MODEL AK-510
Assembly and Instruction Manual
PARTS LIST
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
R10
R6
R7
R4
R13
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
510kΩ 5% 1/4W
620kΩ 5% 1/4W
1.2MΩ 5% 1/4W
1.6MΩ 5% 1/4W
1.8MΩ 5% 1/4W
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
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
green-brown-yellow-gold
blue-red-yellow-gold
brown-red-green-gold
brown-blue-green-gold
brown-gray-green-gold
PART #
133000
145600
153900
154700
157500
162700
163000
165100
166200
171200
171600
171800
CAPACITORS
DESCRIPTION
Discap
Discap
Electrolytic (Lytic)
Electrolytic (Lytic)
Electrolytic (Lytic)
PART #
225080
241031
271045
272245
281044
SEMICONDUCTORS
QTY
1
1
1
1
1
1
SYMBOL
D1
Q1
IC1
IC2
IC3
S1
VALUE
1N4148
MPSA18
LM324
HT2810
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
DESCRIPTION
Diode
Transistor NPN
Integrated Circuit
Integrated Circuit
Integrated Circuit
Infrared Detector
PART #
314148
320018
330324
332810
338L05
350954
MISCELLANEOUS
PART #
517019
520813
540105
541007
590098
623104
623202
626004
QTY
1
2
2
2
1
1
1
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.
BANDS
2
1
Multiplier
Tolerance
IDENTIFYING CAPACITOR VALUES
Capacitors will be identified by their capacitance value in pF (picofarads) 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
Note: The letter “R” may be used at times
to signify a decimal point; as in 3R3 = 3.3
4
5
8
10k 100k .01
9
0.1
First Digit
Second Digit
Multiplier
103K
Tolerance
100
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
-2-
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
connection cool.
The
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
solder
to
cover
the
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
Figure 2
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.
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.
Infrared can be thought of as heat radiation because the radiant energy is transformed into heat 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.
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
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
Figure 3
-5-
of the FET. 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.
FIELD OF VIEW
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.
Figure 4
CIRCUIT DESCRIPTION (see page 16)
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.
Figure 5
OPERATIONAL AMPLIFIERS / FILTERS
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.
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 and 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).
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.
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.
Figure 6
Figure 7
-6-
NEGATIVE FEEDBACK
The open loop gain (or maximum gain) of a typical op-amp is very high
(usually greater than 100,000), enabling a very small input voltage to
drive the op-amp 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.
Figure 8
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.
VOLTAGE COMPARATOR
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.
FILTERS
LOW 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).
Figure 9
Figure 10
HIGH PASS FILTER
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 11
Figure 12
-7-
BAND PASS FILTER
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. 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).
Figure 13
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.
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.
SOUND GENERATOR
The circuit uses an HT-2810 sound generator IC. Figure 14
shows the internal design of the IC. 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.
Figure 14
CIRCUIT DESCRIPTION (see page 16)
Switch SW1 has three positions: LOW / OFF / HIGH. In the LOW mode, the IC outputs a series of pulses at 892Hz,
then a series of pulses at 714Hz to get the ding-dong sound effect. The HIGH mode outputs a series of pulses at
1kHz and a series of pulses at 961Hz. The amplitude of the output of pin 3 is ramped down (see Figure 15) by
placing capacitor C5 from pin 4 to ground. As the voltage from the output decreases, it causes the speaker’s sound
to decrease. This contributes to the ding-dong effect.
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
Band
Diodes have polarity. Be sure to mount them
with the band going in the same direction as
marked on the PC board.
Figure B
Figure C
Flat
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-
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.
Figure D
Notch
These capacitors
are polarized. Be
sure to mount
them with the “+”
lead in the correct
hole as marked
on the PC board.
+
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 - 1.8MΩ 5% 1/4W Resistor
(brown-gray-green-gold)
SW1 - Slide Switch
R16 - 300Ω 5% 1/4W Resistor
(orange-black-brown-gold)
8-pin IC Socket
IC2 - HT2810 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.
-10-
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.
Screws
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.
Figure 20
Angle Lever
Open
Angle Lever
Closed
Plastic Bracket
-12-
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
-13-
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
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
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SCHEMATIC DIAGRAM
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SPECIFICATIONS
Power
Detection Distance
• 9V DC battery
• 30 feet max., best at 4.5’ to 24’
Current
Output Sound
• Operating 60mA (average)
• Standby Typical less than 4mA
Detection
• High frequency / Low frequency tone (Ding-Dong)
• 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.
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