Elenco Electronics AK-510 Assembly And Instruction Manual

MOTION DETECTOR KIT

MODEL AK-510

Assembly and Instruction Manual

Elenco®Electronics, Inc.

ight © 2006, 1994 b

yr

Cop

t of this book shall be reproduced b

No par

y Elenco

®

Electronics

y means;

y an

, Inc.

electronic

ights reser

All r

, photocopying, or otherwise without written permission from the publisher.

ved. Revised 2006 REV-N 753010

PARTS LIST

If you are a student, and any parts are missing or damaged, please see instructor or bookstore.
I

f you purchased this kit from a distributor, catalog, etc., please contact Elenco®E

mail 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. Symbol Description Color Code Part #

1 R16 300Ω 5% 1/4W orange-black-brown-gold 133000
1 R15 5.6kΩ 5% 1/4W green-blue-red-gold 145600
1 R5 39kΩ 5% 1/4W orange-white-orange-gold 153900
4 R1, 2, 8, 9 47kΩ 5% 1/4W yellow-violet-orange-gold 154700
1 R3 75kΩ 5% 1/4W violet-green-orange-gold 157500
1 R14 270kΩ 5% 1/4W red-violet-yellow-gold 162700
2 R11, R12 300kΩ 5% 1/4W orange-black-yellow-gold 163000
1 R13 470kΩ 5% 1/4W yellow-violet-yellow-gold 164700
1 R10 510kΩ 5% 1/4W green-brown-yellow-gold 165100
1 R6 620kΩ 5% 1/4W blue-red-yellow-gold 166200
1 R7 1.2MΩ 5% 1/4W brown-red-green-gold 171200
1 R4 1.6MΩ 5% 1/4W brown-blue-green-gold 171600

CAPACITORS

Qty. Symbol Value Description Part #

1 C8 500pF (501) Discap 225080
1 C9 .01µF (103) Discap 241031
2 C2, C3 10µF 25V Electrolytic (Lytic) 271045
2 C4, C5 22µF 25V Electrolytic (Lytic) 272245
2 C1, C6 100µF 16V Electrolytic (Lytic) 281044

lectronics (address/phone/e-

SEMICONDUCTORS

Qty. Symbol Value Description Part #

1 D1 1N4148 Diode 314148
1 Q1 MPSA18 Transistor NPN 320018
1 IC1 LM324 Integrated Circuit 330324
1 IC2 HT2812G Integrated Circuit 332812
1 IC3 78L05 Integrated Circuit 338L05
1 S1 LHI-954 / KDS245 Infrared Detector 350954

MISCELLANEOUS

Qty. Description Part #

1 PC Board 517019
1 Speaker w/ Wires 520813
1 Switch Key 540105
1 SW1 - Slide Switch 541007
1 Battery Snap 590098
1 Front Cover 623104
1 Back Cover 623202
1 Mounting Bracket 626004

Resistor Battery Snap

Qty. Description Part #

1 Battery Cover 626005
2 Screw #4 x 1/4” 642430
2 Screw #4 x 5/8” 643450
2 Washer #4 (Fiber) 645404
1 Socket IC 8-Pin 664008
1 Socket IC 14-Pin 664014
1 Solder Tube 9ST4

Integrated Cir

cuit

Switch

PARTS

IDENTIFICATION

Note:

the LHI-954 Infrared
Detector is the date code

The text printed on

.

Capacitor

Electrolytic

Discap

Diode

Infrared Detector

Transistor

Integrated

Circuit

Socket

Speaker

-1-

IDENTIFYING RESISTOR VALUES

Use the following information as a guide in properly identifying the value of resistors.

BAND 1

1st Digit

Color Digit
Black 0
Brown 1
Red 2
Orange 3
Yellow 4
Green 5
Blue 6
Violet 7
Gray 8
White 9

BAND 2

2nd Digit

Color Digit
Black 0
Brown 1
Red 2
Orange 3
Yellow 4
Green 5
Blue 6
Violet 7
Gray 8
White 9

2 Multiplier Tolerance

1

Multiplier

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

BANDS

Resistance

Tolerance

Color Tolerance
Silver +
Gold +5%
Brown +1%
Red +2%
Orange +3%
Green +
Blue +.25%
Violet +.1%

10%

.5%

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

10µF 16V

For the No. 01234589
Multiply By 1 10 100 1k 10k 100k .01 0.1

Note: The letter “R” may be used at times
to signify a decimal point; as in 3R3 = 3.3

The letter M indicates a toler
The letter K indicates a tolerance of +
The letter J indicates a toler

103K

100V

First Digit
Second Digit
Multiplier

olerance

T

Maximum Working Voltage

ance of +20%

10%

ance of +5%

The value is 10 x 1,000 = 10,000pF or .01µF 100V

METRIC UNITS AND CONVERSIONS

viation Means Multiply Unit By Or

Abbre

p Pico .000000000001 10
n
µ micro .000001 10

m milli .001 10

– unit 1 10
k kilo 1,000 10

M

nano

mega

.000000001

1,000,000

10

10

1,000 pico units

-12

-9

-6

-3

0

3

6

1.

2. 1,000 nano units = 1 micro unit

3. 1,000 micro units = 1 milli unit
1,000 milli units

4.

5. 1,000 units = 1 kilo unit

6. 1,000 kilo units = 1 mega unit

= 1 nano unit

= 1 unit

-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

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.

2. Apply a small amount of

solder to the iron tip. This
allows the heat to leave the
iron and onto the f
Immediately apply solder to
the opposite side of the
connection, away from the
iron. Allow the heated
component and the circuit

oil to melt the solder.

f

Allow the solder to flo

3.

around the connection.
Then, remove the solder
and the iron and let the
connection cool.
solder should have flowed
smoothly and not lump
around the wire lead.

4.

Here is what a good solder
connection looks like.

oil.

The

Component Lead

Foil

Solder

Foil

w

Solder

F

oil

Soldering Iron

Circuit Board

Soldering Iron

Soldering Iron

Types of Poor Soldering Connections

1. Insufficient heat - the

solder will not flow onto the
lead as shown.

2. Insufficient solder - let the

solder flow over the
connection until it is

vered. Use just enough

co
solder to co
connection.

3. Excessive solder - could

make connections that you
did not intend to between
adjacent foil areas or

minals.

ter

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 dr
iron across the solder
bridge as shown.

ag y

ver the

our solder

ing

Rosin

Soldering iron positioned
incorrectly.

Solder

Component Lead

Solder

Solder

Foil

ing Iron

Dr

Gap

ag

-3-

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

INFRARED

DETECTOR

OPERATIONAL

AMPLIFIERS

TONE

GENERATOR

FILTERS

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 v
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.
water tower, the pressure at the bottom of the
tower can be quite high. In order to keep a
constant pressure in the w
houses, the pressure must be lowered and held
constant.

When water is pumped into a

.

ater pipes that go to the

oltage to

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 v
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

m, the pressure on the lo

ar
increase to close the v
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.

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 (100

alve and allowing more water into

w side will ha

alve. The force or pressure

ve to

Figure 1

µF).

-4-

INFRARED DETECTOR

I

nfrared 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.

w

hen 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.

Figure 2

If you w

ere standing at the beach w
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

een the peaks to 1/2 the original distance.

betw

ould it not be true, the peaks would strike the

W
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

ould sa

w

y “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

ves. The wavelength of

talk about light as lightw

ared light r

infr

anges from .78 micrometers (

a

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

atching the

µm) to

INTERNAL DESIGN

The IR detector contains tw
with each other in opposite polarity and with a 1
millimeter (mm) optical spacing.
are located behind an optical filter or lens (see
Figure 3). The output power of the crystals is very

w. A special device called the Field Effect

lo
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 r
water from a third pipe called the gate. When
pressure (voltage) is applied to the gate
tube closes and pinches off the flo
(current) from source to drain. In a similar manner,
as infrared radiation is detected, the crystals
produce a voltage at the gate

Optical Filter

Crystals

Dual Element Detector Scheme

Infr

Gate

o crystals connected

These two crystals

ubber surrounded b

, the rubber

w of water

of the FET.

ared Rays

Drain

Source
Resistor
Ground

Figure 3

y

-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

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.

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.

OPERATIONAL AMPLIFIERS / FILTERS

An amplifier is a device that uses a small amount
of power to control a larger amount of po
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,

acting, or m

subtr

ational Amplifier or Op-Amp.

Oper

ultiplying v

oltages is called an

The characteristics of an ideal op-amp are the
following:

A. infinite voltage gain (no voltage at all on the

input controls

. infinite bandwidth (no matter how fast the input

B

, large v

oltage on the output).

changes, the output will change just as fast).

C. infinite input impedance (no power required at

input to change output).
zero output impedance (the output can deliver

.

D

er).

an infinite amount of po

w

wer. Just

FET Transistor

Drain

Figure 4

46

O

Vertical

56

56

O

46

O

Horizontal

O

Figure 5

Obviously, in the real world these conditions can

or mathematical purposes the

never be met, b

ut f
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, +V

CC 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

een the v

betw

minals (V3-V2) times the gain of the amplifier (A).

ter

oltage signals applied at its tw

o input

A x (V3-V2) appears at the output terminal as
shown in Figure 7.

Inverting

Input

Non-

Inverting

Input

+Vcc

11

2

3

4

–V

1

Output

EE

V3

2

V2

3

+Vcc

11

A (V3 - V2)

4

–V

EE

1

Output

Figure 6 Figure 7

y

-6-

NEGATIVE FEEDBACK

T

he open loop gain (or maximum gain) of a typical op-

a

mp 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.

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 v

oltages are of opposite polar

ity.

VOLTAGE COMPARATOR

O

perational amplifiers can be used to compare the

a

mplitude 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.

2

R

R1

2

Vi

3

1

o

V

Vo = –(R2/R1) Vi

OR

Vo = –G Vi

Figure 8

FILTERS

LOW PASS FILTER

A low pass filter attenuates (decreases) all signals
above a certain frequency and passes frequencies
below that frequency
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).

. An example of a low pass filter

Figure 9

HIGH PASS FILTER

The high pass filter attenuates frequencies below a
certain frequency and passes frequencies above that
frequency. An e

xample 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 10

Figure 12

-7-

BAND PASS FILTER

T

he combination of a low and high pass filter create

w

hat 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 (f
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.

Gain

C2)

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).

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.

100%

70.7%

W

B

f

c1 fr fc2

f

Figure 13

SOUND GENERATOR

The circuit uses the single sound gener
IC. The HT2812G is a CMOS LSI chip designed for
use in sound effects products. Figure 14 shows the

Divider

Tone

Generator

Noise

ator

Gener

.

Speed

Generator

Selector

and

Envelope

Circuit

Env

nal design of the IC

inter

Osc1
Osc2

Key

Oscillator

y

e

K

Input

Logic

ator HT2812G

Output

Output

Driver

Output

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 lo

w.
When IC1D outputs a voltage lower than 1.41V, it will
force pin 2 of IC1 high. When IC1D outputs a

orces pin 8 and pin 2 of

voltage higher than 1.67V

, it f
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.

CIRCUIT DESCRIPTION (see page 16)

As the Key Input is brought low, the Oscillator, Speed
Generator
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

er

iv

dr
pulses to the base of tr
rapidly, causing the speaker to sound. You can select
between a high and a low tone using switch SW1.

, Tone Generator, Noise Generator and

The output consists of 15 pulses. Appling the

.

ansistor Q1, turns it on and off

Figure 14

y

e

K

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)

R10 - 510kΩ

5% 1/4W

Resistor

(green-brown-yellow-gold)

C9 - .01µF (103) Discap
C6 - 100µF 16V Electrolytic

(see Figure D)

ated Circuit

IC3 - 78L05 Integ

r

(see Figure B)

D2 - Use a Jumper Wire in
place of the diode.

C5 - 22µF 25V Electrolytic

(see Figure D)

Figure B

Note: C7 is not used in this kit.

Figure C

Align the socket notch (if any) with the
notch mar
Solder the socket to the PC board.
Inser
notch as sho

ked on the PC board.

t the IC into the socket with the

wn below.

Figure D

These capacitors are
polarized. Be sure to
mount them with the “+”
lead in the correct hole as

ed on the PC board.

k

mar

Figure A

Band

Diodes have polarity. Be sure to mount them
with the band going in the same direction as

ed on the PC board.

k

mar

Flat

Mount the de
side in the same direction as

wn on the PC board.

sho
Solder and cut off the excess
leads.

vice with the flat

Notch

+

-9-

ASSEMBLE COMPONENTS (CONTINUED)

Jumper Wire (see Figure E)
C1 - 100µF 16V Electrolytic

(see Figure D)

R1 - 47kΩ

(yellow-violet-orange-gold)

C3 - 10µF 25V Electrolytic

R8 - 47kΩ

(yellow-violet-orange-gold)

R7 - 1.2MΩ

(brown-red-green-gold)

S1 - LHI-954

Mount with tab in the same direction as
marked on the PC board (see note below).

R14 - 270kΩ

(red-violet-yellow-gold)

R13 - 470kΩ

(yellow-violet-yellow-gold)

SW1 - Slide Switch
R16 - 300Ω

(orange-black-brown-gold)

8-pin IC Socket
IC2 - HT2812G

5% 1/4W

(see Figure D)

5% 1/4W

5% 1/4W

Infrared Detector

5% 1/4W

5% 1/4W

5% 1/4W

Integrated Circuit

(see Figure C)

Resistor

Resistor

Resistor

Res.

Resistor

Resistor

Red

–

+

Black

Inside Pads

Outside Pads

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.

t the red wire into the (+) positive hole and the black

Inser
wire into the (–) negativ

e hole as shown above.

Note: The text printed
on the LHI-954

ared Detector is

Infr
the date code.

Q1 - MPSA18 Transistor

(see Figure B)

R15 - 5.6kΩ 5% 1/4W Resistor

(green-blue-red-gold)

Speaker Wires - Solder the
two wires to the PC board
marked SPK +, –.

Note: If wires need resoldering;

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
unsolder these wires.

NOT

Figure E

Use a discarded lead f
a jumper wire.

or

-10-

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.

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.

#4 x 1/4” Screws

#4 Washers

Figure 16

Switch Key

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 17

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.

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.

Battery Cover

Figure 19

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

-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 shor

t between point B and GND.

C. Voltage at point C incorrect:

.

k R2, C2 for correct v

Chec

1.

2. Check for a short between point B and GND.

alue

C

OPERATIONAL AMPLIFIERS

3. Measure the voltages at IC1 while the unit is at standby.

Pin Voltage Pin Voltage

1 3.80V 8 –
2 – 9 1.62V

B A

3 1.40V 10 1.60V
4 5.00V 11 –
5 1.40V 12 1.52V
6 1.60V 13 1.55V
7

–

14

1.50 - 1.60V

-13-

4. Measure the voltages at IC1 when activated.

Pin Voltage

1 0 - 3.8V
7 0 - 3.8V
8 0 - 3.8V

14 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 Voltage Voltage

Pin No Sound Sound

No voltage at pin 3:

A.

1. Check R13, R14, SW1 and C5.

B. No 5V at pin 5:

1. Check SW1 solder connection.
No 5V at pin 6.

2.

3. Check C9.

C. Outputs two short tones:

1. Check C5.

3 0 0 - 4V
5 5V 5V
65V
7 0V .735V

Q1 Voltage Voltage

Pin No Sound Sound

E0 0V
B 0V .355V
C 9V 7 - 9V

Q1

E B C

-14-

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. V

1 and V2.

C. VEE and VCC.
D. gates.

7. A high pass filter attenuates all signals . . .

between two frequencies.

A.
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.

-15-

s:

wer

1.

B

, 2. D, 3. D, 4. D, 5. B, 6. A, 7. B, 8. D, 9. C, 10. B

Ans

SCHEMATIC DIAGRAM

-16-

SPECIFICATIONS

Power

• 9V DC battery

Current

• Operating 60mA (average)

• Standby Typical less than 4mA

Detection

• Pyroelectric Infrared Sensor.

Detection Distance

• 10 feet max., best at 1’ to 6’

Output Sound

• High frequency / Low frequency tone (15-pulse siren)

• 85 - 90dB peak

Operating Range

• –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 v
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.
Frequenc
Gain To increase or make larger.
Gate A device used to allow or restrict passage.
Generator A de
Impedance A device’s resistance to the passage of electrical current.

y

The repeated occur

vice that transforms energy into electric power or signals.

ance of anything at brief intervals.

oltage differences.

Infrared Light Ra
IR Detector A de
Kit A collection of equipment or components.
Lambda The ele

ys past the red end of the visible light spectrum.

vice that senses the presence of infrared light.

enth letter of the Greek Alphabet.

v

-17-

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.

viding resistance in a circuit.

Resistor An electric element used f

or pro

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 unco

vering 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

ack R. White

By J

Dodd, Mead, © 1984

k:

or

Y

w

Ne

.; ill.

124 p

Waves and Vibrations

By Brian Knapp

y, CT: Grolier, © 1994

ur

Danb

ill.

.;

48 p

-18-

Elenco®Electronics, Inc.

150 Carpenter Avenue

Wheeling, IL 60090

[phone]

Web site: www.elenco.com

e-mail: [e-mail]