Powercom Tree of Knowledge INTERCOM LAB User manual

HAVE FUN AND LEARN ABOUT ELECTRONICS!
INCLUDES 2 CONSOLES . BUILD 2 PROJECTS AT THE SAME TIME!
Assemble your ovun: intercom, photocell alarm,
lie detector, moisture meter and other simple projects.
TREE OF KNOWLEDGE

INTRODUCTION TO YOUR
INTERCOMLAB
This kit is desioned os on introduction to the world of electronics. you will leorn obout the
different como-onenrs. ho* io ;;;k-ryi[r"tii"iry; h;; ;';;.j'.i,."r], diosroms, ond
finolly, you will build vorious it"rr'rirtiyoJ'.'on prt to good use.
Among the severol devices thot you will build with ihis kit is on intercom. The iniercom is
the most difficult circuit,, ond the'refore *"lrgg"rt you reove it to the end ond buird it os
vour finol proiect. _The.kit incruJes.two ;;;J;r,.16i["it;; .ri Lrrra 2 differenr circuirs
ol lhe some time. The instructions for ihe os".-uting ;;;(;;;ffire identicol. Build rhe
inrercom ofter vou hove compreted qlr of tt," .*", Eir.iit ,;;; ijirr ^*a rhe rwo
consoles for it.'
Before you stort working with this kit, p.leose reod the seporote consore ossemblv
inskuctions. Do nor open the lqgs in ihe kit untiL y;, h;;; ;;d;;;; ilr";ii;',
components on o convenient toble. lt is best to w6rk on o cleon, lorg" oia'iijht ,r#o"",
os there ore mony smoll ports which con t" "o1iivlo,
This is o kit for those who. wish lo try their hond ot building simple electronic devices,
without soldering, without complic;ieJ;".iins'"quip*ent,'qnd with simple inshuctions. lt is
importont to remember rhor oll elecrronic "qrhr"nri 1i;;1" ;;"il;n i.", r, presordered,
i"*",HtriiJit';ff"1ff ',"#::?{*:;'*tgn*trriltifl ::ffi ',Htffiffi ,f ,
best to work slowlv, ond ro doubrechec( "** it"p. -ti, ;i.,;; .yJ,"h:ff .#rur. "'Jrr.rri
ond it does noi function, do not despoir. ihir'hopp"n, to every engineer, ond this is olso
the best woy to leorn.
gqNERAl /NsrRUCr/oNs AND ctRCUtT ExpLANATtoNs - in this booklet
33|r,?'i,trif\i!{^Hf:ry,il,.ilrdx,l*,uy;"?li;!rr!ii_
su9GEsT!9Ns: Some of you moy hove occess to odults who understond elechonics
ond wish to helo vou. These'odurts moy t.y onJ orr"rb[';h;';Ii; projects wirhout
lookins.ot the clriuit ai.og.,'-ei;"';;;H;'" ii;;ii';"ft;r;;;i"rp, thor oil or the
written instruciions ore followed. The circuii diogroms ore used uv proi"'r5on;'i;."'ih: "''
diogroms include informotion ro,. tt'" p"rr* *ii,urriir tl".ffil iii is similor ro rhe
novigotor who reods o mop before ittempri"t t" "rpti;;'**'.;;.
g:.gA$LUJ yy11ry-Vffi yurH sHARp porNrs oR;
KEEp_AwAy FRoi,l GHIDREN uNoii iiinrf vilris 6i ace
USE ONIY BATTERIES.
IIE USE OF ANY OTH.ER EI.ECTRICAL SOURCE IS DANGEROUS.
Pg NOr ,Yltx orD AND NEW sarrrnurC.
Pg NOT t^tx AIKAUNE AND STANDARD BATTERIES.
DO NOT USE RECHARGEABTE
ApuLTs ARE ApvrsEp ro REAp'rrANt+ rilioluiiniGi'-viliiii NEcEssARy.
@ 1997, Tree of Knowledqe llg7gl
No port of this publicotiorimoy.be'reproduced or tronsmitted, in ony form or by ony
meons, without permission in writing from the prUti"t"i.- 'vY' rrr vrr,'

COi,IPONENTS
PLEASE NOTE:
DO NOT USE COMPONENTS UNTIL YOU HAVE MARKED THEM WITH THE APPROPRIATE
STICKERS I
b-t!,Llllt there qre two,types of diogroms (or drowings) of on electronic circuit:
SCHEi ATIC - which shows q circui-t ond iis componEnis in theorv- -
PICTORIAI ' which shows the octuol connections ond the comjonents of o circuii.
WIRES: The colours of the wires, with the exception of the red ond block wires,
ore not importont.
PHO[QEEI! -. The photocell used in this kit is on LDR, (LIGHT DEpENDENT RES|STORI. tt
is o resistor whose resistonce vories occording to light intensity. ln our LDR, the hioher t[re
light, the lower the resistonce. The LDR in this"kit isiseJ ir.irlritr *itt *ii.ri itgX;- ' "'"
controlled systems.
ScREWS -.Some of the sc.rews ore,,the 'Phillips" type, ond some qre ordinory screws. Both
types con be tightened wiih o smoll screwdriver.
You should hove the oid of on odult whenever ossembling ond instolling
componenls where screws ore required.
COMPONENT SCHEMATIC PTCTORIAL
RESISTOR
Direction is not importanl 9l0K
{AA @F
CAPACITOR
Dhectlon is not important 0-l u
{F- -r@
ELECTROLYTIC CAPACTTOR
Dtfil,allon l.wry tn,onr/nz .22L
llF -@
DIODE (silicone)
Dtrtotlon l. wry lnpr?lal lN4t4E
{+- ...(D
LED (Light.mmiting diode)
Follow instructions in terll, +F' "-o*
PHOTOCELL
Dircction is not important, -G -@-
IT,ITEGRATED CIBCUIT LM 324
Follow instructionc in text. #
OFF/ON SWTCH
Follow inotructions in lf-rt. sk- \t\
BATTERY CONNECTION
(power source) {rl- TH
LABELLI N G COI/IPON ENTS
You should lqbel the legs of oll of your components like this:
Rf5/5roRS
Professionol electronic engineers use o stondord colouiicode for the volues of resistors. Use
l}".ff 'H:t;'"rp?""i,n:.'I:f 5y,'l1lifl :9"',X1'y,:11i"*,i,t*;#l*T;;"""
printed card.

DIODES
Lobels should be ploced on the leg neorest the block line on the diodes.
CAPACITORS . ELECTROLYTIC AND CERAII'IC
There ore 2 types of copocitors included in this kit. Lobel them oll occording lo the number
written on th6m. Ploce'the lobel on the longest leg of the Elecirolytic coPocitors.
Pleose note thot the Electrolyiic copccitors must be connected os morked on the
circuit diogroms, positive to "+", or negotive to "-". You will see either the morking '+"
or " -" onjhe side of the copociior. SJme Ceromic capocilors moy hove different
numbers orinted on them os below:
. O.Ol *hi.h it morked either l0nf, or 0.0,1 or ,I03
. 0.i which is morked either l00nf, or 0.0,1 or I04
. 100pf which is morked either 470, or 471
THE LED (LIGHT EILIfiING DIODE)
The LED llioht Emittino Diodel is o soeciol kind of DIODE lDiodes ore exploined in o
seporote'sJction). W[en current flows through them in the proper direaibn they will
light up. How biight the.light will..be depends on the quontity.of the currenl- [EDs
ore very sensitive, so only o smoll omount of current con go through lhem.
Whenever you use them,'moke sure thot you use resistors in series with them,
otherwise you moy overlood them ond then they will not give off light. You must
olso be very coreful not io put them in bockrrords, becouse thot con ruin
lhem os well!
TNSTALLTNG rHE LED: B @ @
Do this corefully becouse if the LED is connected incorrectly, you Il II ll
mov domooe ii. Eqch LED is morked to differentiote the CATHODE ll ll ll
fror{r the AKODE. This is done in severol different woys, but it is Al ll'. ll..
olwoys thqt cothode thot is morked. ldentify ihe cothode. c'l llc ll cArHoDE
YOU ARE NOW READY TO START YOUR FIRST CIRCUIT I
REMEMBERs ASSEMBLE THE INIERCOTII AS YOUR FiNAL PROJECT ,
DO NOT USE ANY SOURCE OF ETEGTR.ICITY OTHER. THAN A 9Y BATTERY!
BLACK O O X
BROWN I I X
RED22X
ORANOE 3 3 X
YELLOW 1 4 X
OREEN 5 5 X
BLUE6SX
VIOLET 7 7 X
OBAYSSX
wHtTE S I X
THE FOUHTH BAIiID INDICATES TOIEENNCE (AOCURAGY):
GOLD - t 5!f, SILVER . + 10lf, NONE -r.z(fr
1\
10\
r00
l,(xro
10,(x10
100,(x)0
'1,o(xr,ooo
10,(x10,000
100,0-00,-000
COTOR CODE

j
I
Circuit No. 1 BLINKER
This circuit is bosed upon on oscillotor which operotes on o low frequency. Only o few
oscillotions per second will couse the LED to blink. The oscillotion is determined by
the components. lf you chonge lhe 2.21rF copocitor ond use the 1OpF copocitor
insteod, you will slow down the blinking by opproximotely 20 times.
Circuit No. 2 TIMER
Toke 2 wires. Connect one end of one wire toTerminol T'l , ond the second wire end
to T2. Touch the bore ends on the other ends of the wires together. This will cquse the
LED to light.
When you breok this connection, the LED will remoin lit for q few seconds.
The connection between Tl + T2 chorges the copocitor.
When the connection is broken, it dischorges slowly through the 240K resistor.
Circuit No. 3 LIGHT ACTMTED AI-ARM
When the photocell detecis light, it will light the LED.
To moke the photocell more sensitive, find o smoll tube, ond put it over the photocell so
thot the lioht is directed to the cell. This will mqke it more sensitive.
The other"method is to chonge the volue of Resistor RX. Use o resistor close to l0K.
Circuit No. 4 AUTOMATIC DARK SENSOR
This is the some os your light-octivoted olorm-sensitive circuit, only it works the opposite
woy. The LED will light os long os it is dork. As soon os light folls on the photocell, the
LED will e*inguish. To moke it more sensitive, follow the instruciions in the previous circuit.
Circuit No. 5 NOISE DETECTOR (ACTMTED LED)
This is o sound<ctivoted circuit. When you moke o noise close to the speoker, it will couse
the LED to lioht. ln this circuit. the soeoker is used os o microohone.
When o noile is mode, the speoker froduces o very smoll current which is then omplified.
This chorges ihe 0. lpF copocitor. When this is chorged enough, it couses the LED to light.
Circuit No. 6 GROUND HUMIDITY METER
This circuit con be used for checking the moisture in potted plonts. When the soil of the
plont is dry, the LED will light. The"moister the soil, the w".ik"r the light will be. To operote
this, toke 2 wires. Strip off the insulotion (obout 3 centimeters) ot one end of eoch of the
2 wires. This will be your moisture detector. Push the bore ends o[ the wires into the soil,
obout 2 cm oport from eoch other. Connect the other ends of the wires to terminols Tl
ond T2. lt does not motter which wire goes to which terminql.
The sensitivitu is determined bv three foctors: Try resistors between 'l 0K to 1 .3M.
21 T6e lenoth of the bore wire thot is inserted in'to the soil.
3i The disttnce between the 2 bore ends of the wires in the soil.
For repeoied.results, olwoys try to use the some resistrcrs ond length ond distonce between
the wires in the soil.

Circuit No. 7 SIREN
This circuit creotes o voltoge controlled oscillolor, which is determined by the copocitor,
connected between block I qnd No. 2 of the lower yellow housing. lf you chonge this,
the oscilloior will chonge in sound.
Circuit No. 8 ALARM
This operotes by o simple principle of breoking o very thin wire which you con put oround o
door, window, ond the floor, etc. While the thin wire is unbroken, the circuit is closed. As
soon os the wire is broken, the oscillotor storts sounding on olorm, through the loudspeoker.
Circuit No. 9 SOUND GENERATOR + LIE DETECTOR
This is q Sound Generotor which you build in one console {A) ond you connect it to on
omplifier in the second console (B).
The connections between the 2 consoles ore with two wires from Terminols Tl ond T2.
You con experiment with the frequency ond chonge the tone. To do lhis, chonge the
copocitor 0.lpF (CP) in Console A, wiih the other copocitors in your kit, ond moke sure
thol the + (positive) ond - (negotive) ore connected correctly.
MAKE YOUR OWN LIE DETECTOR
lnsert 2 wires in Console B, insteod of the copocitor morked CX.
Hold the end of the bore wire. You will notic'e o chonge in the tone o[ the sound.
As you know, when people tell o lie, they tend to sweot ond their honds get wet.
This will chonge the iesistonce ond thereflore, the sound. This of course, is not o scientific
detector, but ii does exploin the principle. You con use this on two people eoch holding
the oihers' hond, ond then holding the bore wire with their other hond.
Circuit No. 1O INTERCOM
The intercom is the most difficult circuit to consiruct.
This is the first thino to do before vou stort:
Disconnect the switfhes in both consoles, Post B, ond the slider.
Connect the block wire from the boitery holder to B ond the red wire to C.
Toke o wire from the slider switch through hole 3 ond connect to J.
Toke o wire from Post B through one of the smoll holes obove I + 2, ond connect it to A.
Do this in both consoles.
ln your kit you will find o length of wire which hos 3 seporote stronds o[ wire.
Connect these between Consoles A ond B os shown in the diogrom.
You must moke sure thot you connect these one ol o time
so thqt you do not cross ihe wires.
HOW THE INTERCOM OPERATES:
When the switch in Console A is in the "down" position (switch open), the switch in
Console B hos to be in ihe "up" posiiion (switch closedl.
ln ihis position, onyone speoking in Console A will be heqrd in Console B.
When you reverse this, you con speok from "B" to "A."

BEFOR.E BEGINNING IHE CIRCUIT CONNECTIONS:
You hove o seoorote booklet with oll of the instructions for ossembling ten different circuits.
Eoch circuit intludes o schemotic drowing, o circuit drowing ond o check list exploining
eoch connection. We hove left blonk sqrJores on these checklists so thot you con check-
off eoch connection vou hove mqde. Pldose note thot circuits #9 + #10 dre the most
complex, ond theref6re eoch of these circuits ore exploined on two poges, rother thon
on only one poge.
Don'l oanic - electronics is reallv lots of fun!
ln order to ensur'e your success- with. these circuits, we suggest thot,before octuolly
storting, try to connect some of the bosic comPonents to lh-e circuit boord.
Circuit A will show you how to connect ond light o LED.
Circuit B will show you how to connect ond light o IED ond o copocitor.
Circuit C will show you how to connect ond light o LED, o copocitor ond o diode,
ond you will ossembl6 o simple forword-reversdcircuit.
Il
Y)
I
dEt
T2
I-----l
H'm H,
t- - - - -l
"H H,
A-)(-)A
4-)k+(:
A+ I,ED -)B
B+4700-fu
6

Pleose reod ond understond oll instructions before proceedino with your work. We suooest
thot before ossembling, toke o morking pen ond mtrk the nr"rb"i. L.J t"tt"r, .; ti;l;Yil;
ot lhe console os thev oopeor on ihe dioorom. This will moke the ossembling simpler for you.
you should hove ihd iia Jon-"Juli;i";;;; iJii,iEril"iiij'inrr"li:ng-' '""
componenls where screws ore required.
N
r-f
ffito
Ja ffi
2. Now push the ossembled housing into the slots on rhe front of the console. (Figure 3!
ASSEttBLtil6 TtlE CoNS0LE
lsruPll PREPARTNG THE coNSoLE
l. Firstly you need to insert ihe metol connectors into the yellow housing. {Figure 2}
rE P]Z ATTAC H tN G Yo u R B ArT
ERy
Turn the console upsidedown so thot the speoker qrill touches fie toble.
AlToke the smoll metol cops ond press theh into e-och of the posts A, B, ond C.
FIG,l
FIG.2
FIG.3
(Figure 4)
FIG.4
FIG.5
B) Find the bottery snop. Toke the red wire
ond wrop the uninsuloted port of the wire
oround the screw in o clockwise direclion
on.posi B. Now lighten this screw,
moking. sure thgt the wire sits securely
under the heod of the screw.
(Figure 5)
C) Toke the block wire of the bottery snoo
ond choose the block wire from vtrr kit-
Wind them both oround the screw in oost
A. Tighien the screw os you did befoie
on post B. Poss the other end of the
block wire through the hole morked ',6.,,
D) You moy need Post C loter.

THE SWITCH
The switch is mode for ooenino ond closino Op"n, T
q circuit. ln diogroms, it is moted like this.] N
To ossemble your switch. follow these instructions:
llToke. the-switch slider (Figure 6) ond push it through the oblong hole between Posts B & C.
Do this from the front of the console. FIG.6
2) Slip the lorge spring spocer over the squore .This holds the slider in ploce. {Fig.{
FTG. 7
ti:l:i:t:t\::!jiit;::.1 l:i:-li
z!],,,,1!:jll:,::: ::!, &I
&
protrusion
3) Toke the red, loose wire ond wrop the uninsuloted port of the wire oround the screw, so
ftot the wire rests between the wosher ond the heod of the screw. Now lighten the screw
into the slider. Push the other end of the wire through the hole morked "2". (Figure 8)
4! To test the switch, push the slider bock ond forth. The wosher should touch post B
eoch time.When the slide is up ond when you push it down, the morker should touch
post C. Your console should look like this: (Figure 9)
l THESPEAKER
A)floce the speoker foce
down on the orill os
shown in figu;e lO.
..'''.-EB..+.*-
cur"a, f,_
eg
FIG.8
FIG.9

B! Toke the bottery cover ond screw down wiih 2 long screws. (Figure I l)
C) Push the speoker wires through
FIG. 11 holes 3 & 4. Your console should look like Figurel2.
FIG.12
@ fHE TNTEGRATED ctRCUtT (tc) Frc. lrA
Lobel the centrol yellow housing on your boord with numbers.
Study tig.ure l3A. lt is importadr fhof rhis is corn ct.
A).loke th-e.lobel numbered I - 7. This lobel will oo ot the
bose of the lower yellow housing. Nr.t", i ;h"*H b;
ploced directly below rhe firsr h-ole on the left.
Bl lJory toke.the lobel I - 14. ploce oilhe top of rhe uooer
block so thor I4 is directly obove the firri't"t" oni[5i"H.
Now odd the lnteorored circuit (rc) ro yorrr consore. corefuily study the figures berow.
I!:.1! l: ?.d"t',."ip component oniyo,';fuE'[;;; #'h1fi,oi'llroiirt, rhe nexr bir.
t-irst stroighten both sides of the pins'so rhonhey or" foroii"l i";;j[;; fress the ourside
edge of ihe pins.very gently on.I fi;i;r;f*;:-6" coreful noro over-bend them. The holf
moon shope on the lC is ploced nexl to the holf moon on tt'" ."ni"i".-ir"-riJJ i1,"iil';i..
motch up with the holes iently insed thern into tlie """i.f yl[,r-L-rrinJ'"ro.tly os in rhe
fol low i n! d ios ro m s. oircl #. rC i" ii"r"ti;i;-titi';;i il"L' ffi J,"a.
Fromihis:7] Tothis: ffi
f-sr l THE TERvL4INALS 0 & r)
To prepore T &.T terminols, toke o wosher, o sprino os in fioure ly'
ond screw it o linle woy into rhe rwo.q;r; h;i;;";r[;j"-'" '-'
T ond T.
These terminols ore used in severol circuits ond ore morked with o
broken line J-;- I where yo, n""J i" "JJ " *rc-.- r Jo"inoi iJtr",
wnrch..end. ot,the wire you connect to which terminol. Moke sure the
rnsurohon is creoned ott rhe copper. The connection is mode bv oushino
the.wosher down on the spring,'*ropping ihe;;; ";;ilrh;'J:;:"'"
ond releosins rhe wosher'so tllt it ti.itJ.ih;;i;;"dtr;iti.'" fr"".i"lf
Ine screw.
FIG. 14
&B
yau HAYE ilow cofrptEfflD ASSEttDttNG fHE COttSOtE.
@ 1997, Tree of Knowldege