terminating and connecting of electrical wirings and electronics circuits
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HowtoUsethisModule.......................................................................................................
Introduction..........................................................................................................................
TechnicalTerms....................................................................................................................
LearningOutcome#1.......................................................................................................... 1
InformationSheet#11....................................................................................................... 2
OperationSheet#11.......................................................................................................... 6
LearningOutcome#2.......................................................................................................... 8
InformationSheet#2.1....................................................................................................... 9
ActivitySheet#2.1............................................................................................................ 10
LearningOutcome#3........................................................................................................ 13
JobSheet
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Welcome to the Module Terminating and Connecting Electrical Wiring and
Electronic Circuits. This module contains training materials and activities for you to
complete.
The unit of competency Terminate and Connect Electrical Wiring and Electronic
Circuits contains knowledge, skills and attitudes required for a Computer Hardware
Servicing NC IIcourse.
You are required to go through a series of learning activities in order to complete
each of the learning outcomes of the module. In each learning outcome there are Job
Sheets, andActivity Sheets. Follow these activities on your own and answer the Self-Check
at the end of each learning activity.
If you have questions, do not hesitate to ask your teacher for assistance.
Recognition of Prior Learning (RPL)
You may already have some of the knowledge and skills covered in this module
because you have:o been working for some timeo completed training in this area.If you can demonstrate to your teacher that you are competent in a particular skill or
skills, talk to him/her about having them formally recognized so you do not have to do the
same training again. If you have a qualification or Certificate of Competency from previous
trainings show it to your teacher. If the skills you acquired are still current and relevant to
this module, they may become part of the evidence you can present for RPL. If you are not
sure about the currency of your skills, discuss it with your teacher.
After completing this module ask your teacher to assess your competency. Result of
your assessment will be recorded in your competency profile. All the learning activities are
designed for you to complete at your own pace.
Inside this module you will find the activities for you to complete followed by
relevant information sheets for each learning outcome. Each learning outcome may have
more than one learning activity.
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Program/Course : Computer Hardware Servicing NC II
Unit of Competency : Terminate and Connect Electrical Wiring and Electronic
Circuits
Module : Terminating and Connecting Electrical Wiring and
Electronic Circuits
INTRODUCTION
ThismodulecontainsinformationandsuggestedlearningactivitiesonComputerHardware
Servicing NC II. It includes the following competencies: plan and prepare for termination/
connections of electrical wiring/electronic circuits, terminate/connect electricalwiring/electronic
circuits,andtesttermination/connectionsofelectricalwiring/electroniccircuits.
Itconsistsofthree(3)learningoutcomes.Each learningoutcomecontains learningactivities
supportedbyeachinstructionalsheet.Uponcompletionofthismodule,reporttoyourteacherto
assess your achievement of knowledge and skills requirement of this module. If you pass the
assessment,youwillbegivenacertificateofcompletion.
SUMMARYOFLEARNINGOUTCOMES:
Uponcompletionofthemoduleyoushouldbeableto:
LO1. Planandprepareforterminationandconnectionofelectricalwiringandelectroniccircuits.
LO2. Terminateandconnectelectricalwiringandelectroniccircuits.
LO3. TestTerminationandconnectionofelectricalwiringand/electroniccircuit.
REFERENCES:
1. Agpaoa,Feliciano,InteriorandExteriorWiringTroubleshooting,NationalbooksStore,19912. Enriquez, Michael, Simple Electronics (Basic) Fully Illustrated, Antonio M. Andes Sr.ElectronicsBookSeries
3. www.electronicslab.com4. www.wikipedia.com
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Voltage The measure of the push on each electron which makes the electron
move. The term potential difference and voltage are often used
interchangeably to mean the push, thus, you may see the term
electromotive force (EMF) orjust the word potential to describe the
electronpushincertaininstances.
Current Theflowofelectronsinthecircuit.
Resistance Theoppositiontocurrentflow.
Power Therateofdoingwork.
Resistor Adevicedesignedintentionallytohaveadefiniteamountof
resistance
Capacitor Adevicethatstoreselectricalenergy.
Termination - The point where a line, channel or circuit ends.
OHS OccupationalHealthandSafety
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Program/Course : ComputerHardwareServicingNCII
UnitofCompetency : TerminateandConnectElectricalWiringandElectronic
Circuits
Module#3 : TerminatingandConnectingElectricalWiringandElectronic
Circuits
LearningOutcome1:PlanandPrepareforTerminationandConnectionofElectrical
WiringandElectronicCircuits
AssessmentCriteria:
1. Materialsarecheckedaccordingtospecificationsandtask.2. Appropriatetoolsandequipmentareselectedaccordingtotaskrequirements.3. TaskisplannedtoensurethatOHSguidelinesandproceduresarefollowed.4. Electricalwiringelectronicscircuitsareappropriatelypreparedforconnection/
terminationinaccordancewithinstructionsandworksiteprocedure.
References:1. Agpaoa, Feliciano, Interior and Exterior Wiring Troubleshooting, National booksStore,19912. Enriquez,Michael,SimpleElectronics(Basic)FullyIllustrated,AntonioM.AndesSr.
ElectronicsBookSeries
3. Cardenas,Elpidio,FundamentalsandElementsofElectricity,NationalBookStore,1991
4. www.wikipedia.com
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DirectCurrentandAlternatingCurrent
DirectCurrent
orDCisthefirsttypeofcurrentbecauseitwaseasytoproduce.Thistypeof
currentalwaysflows inonedirection.OneofthedisadvantagesofusingDCistheexcessive
voltagedropandpowerlossinthepowerlinesinalongdistancetransmission.Batteriesare
commonsourcesofdirectcurrent.
AlternatingCurrentorACisthesolutiontotheproblemofDC.ACallowstheflowofcurrent
intwodirections.Today,itispossibletostepupelectricity,apowerstation,transmititto
anydistantplaceandstepitdowntoforconsumption.Atransformeristhedeviceusedfor
steppingup
or
stepping
down
AC
voltage.
Common
sources
of
AC
are
found
in
our
AC
outlet(Typically,220volts,inthePhilippines).
OHMSLAWANDPOWERLAW
Ohms law states that, for a constant current, the current in a circuit is directlyproportional to the totalvoltageacting in the circuitand inversely proportional to thetotalresistanceofthecircuit.
ACandDCWaveForm
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ThelawmaybeexpressedbythefollowingequationifthecurrentIisinamperes,EMFEisinvolts,andtheresistanceRisinohms.
The relationship of the foregoing three variableswasdiscovered by Georg
Simon
Ohm,
who theorized that current is in direct proportion to resistance. The relationship is
explainedalgebraically,usingthisformula:
R = E/I
Resistance
E = I x R I = E/R
Voltage Current
where:
E EMF in Volts
R Resistance
I Current in Amperes
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A. PracticeProblems:1.
2.
E=25VR=25
Required
G. I
H. P
I=?
E=?R=72
Required
E. E
F. P
I=9A
E=?P=100W
Required
C. R
D. E
I=25A
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3.
E=?P=350W
Required
A. E
B. R
I=4.5A
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ASimplecircuitcontainstheminimumthingsneededtohaveafunctioningelectric
circuit.Asimplecircuitrequiresthefollowing:
AC/DCsource EquipmentthatwilloperateoneitheranACorDCpowersource BatteryAdcvoltagesourcecontainingtwoormorecellsthatconvert
chemicalenergytoelectricalenergy.
Cell Single unit used to convert chemical energy into a DC electricalvoltage.
FUSEOnceyoudesignasimplecircuitonelectronics,it
isimportanttoincludea fuse in the primary or
secondaryofatransformer.
Fuse is a safety device used to protect anelectricalcircuit from theeffectofexcessive
current. Itsessential component is usually a
strip of metal that will melt at a given
temperature.Afuseissodesignedthatthestripofmetalcaneasilybe
placed in the electric circuit. If the current in the circuit exceed a
predeterminedvalue,thefusiblemetalwillmeltandthusbreak,oropen
thecircuit.
A fuse is usually rated in Amperes, which represent the maximumcontinuouscurrentitcouldhandlewithoutblowing.
The most popular type of fuse in Electronics is 3AG type. This codedescribes the case size and material where G indicates a glass
materialsandA indicatesthat intendedforautomotiveapplication.A
3AGfusemeasuresapproximately32mmx6mm.
WiresandCable Awireisasingleslenderrodorfilamentofdrawnmetal.Thisdefinitionrestrictstheterm
to what would ordinarily be understood as
solidwire.Thewordslenderisusedbecausethe length of a wire is usually large when
comparedto itsdiameter. Ifawire iscovered
with insulation, It is an insulated wire.Although the term wire properly refers to
themetal,italsoincludestheinsulation.
Aconductor isawire suitable forcarryinganelectriccurrent.
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A stranded conductor isaconductor composedofagroupofwireoranycombinationofgroupofwires.Thewires inastrandedconductorareusually
twistedtogetherandnotinsulatedfromeachother.
A cable is either a stranded conductor (singleconductor cable) or acombination of conductors insulated from one another (multipleconductor
cable).Thetermcable isageneraloneandusuallyappliesonlytothe large
sizesofconductor.Asmallcable ismoreoftencalledastrandedwireorcord
(suchasthatusedforanironoralampcord).Cablesmaybebareorinsulated.
Insulatedcablesmaybesheathed(covered)withlead,orprotectivearmor.
Switchanditsfunction Switch isadeviceusedtobreakanelectriccurrentortransfer it toanother
conductor.Switchesarecommonlyusedtoopenorcloseacircuit.Closed is
theONposition,whileopen isOFFposition.Normally, switch is installed in
serieswiththe linecarryingcurrentfrom
thepowersourcetotheload.
A switch is a mechanical device used toconnect and disconnect a circuit at will.
Switches cover a wide range of types,
from subminiature up to industrial plant
switching megawatts of power on high
voltagedistributionlines.
Switch is a manually operated devicecapableofmaking,breaking,orchanging
the connection in an electronics or
electrical circuit. A switch connected in
serieswithoneof theconnectingwiresofsimplecircuitaffordsameansof
controllingthecurrentinthecircuit.
Switchfunctiono When theswitch isclosed, theelectron findsan interruptedpath in the
circuit.
o OpenistheOFFpositionoftheswitch,whileclosedistheONposition.o Whentheswitch isopened,thecurrentdeliveredbythepowersupplyis
normallyinsufficienttojumptheswitchgapintheformofanarcandthe
electronflowinthecircuitisblocked.
Load a source drives a load. Whatever component or piece of equipment isconnectedtoasourceanddrawscurrentfromasourceisaloadonthatsource.
o Thefollowingareexamplesbutnotlimitedto: Bulb Appliances
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I. ClassificationsofElectronicComponentA. Passive devices A Passive Device is one that contributes no power gain
(amplification)toacircuitorsystem. Ithasnocontrolactionanddoesnot
requireanyinputotherthanasignaltoperformitsfunction.Inotherwords,
"A component with no brains!" Examples are Resistors, Capacitors and
Inductors.
RESISTOR
Thisisthemostcommoncomponentinelectronics.
It is used mainly to control current and voltage
withinthecircuit.Youcanidentifyasimpleresistor
by its simple cigar shapewithawire lead coming
out of each end. It uses a system of color coded
bands to identify the value of the component
(measuredinOhms)
Capacitors,or"caps",varyinsizeandshape from
asmallsurfacemountmodeluptoahugeelectric
motorcapthesizeofpaintcan.Whateverthesize
or shape, the purpose is the same. It storeselectricalenergyintheformofelectrostaticcharge.
It is chargedwithamagnetic fieldandwhen that
field collapses itproduces current in the opposite
direction.InductorsareusedinAlternatingCurrent
circuitstoopposechangesintheexistingcurrent.
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B. ActiveDevicesarecomponents thatarecapableofcontrollingvoltagesorcurrents and can create a switching action in the circuit. In other words,
"Devices with smarts!" Examples are Diodes, Transistors and Integrated
circuits.
Diodes are basically a oneway valve for electrical
current. They let it flow in one direction (from
positivetonegative)andnotintheotherdirection.
Mostdiodesaresimilar inappearancetoaresistor
andwillhaveapaintedlineononeendshowingthe
direction or flow (white side is negative). If the
negativeside ison thenegativeendof thecircuit,
currentwill flow. If thenegative ison thepositive
side
of
the
circuit
no
current
will
flow.
LEDsaresimplydiodes thatemit lightofone form
or another. They are used as indicator devices.
Example:LED litequalsmachineon.Theycome in
several sizes and colors. Some even emit Infrared
Lightwhichcannotbeseenbythehumaneye.
The transistor is possibly the most important
invention of this decade. It performs two basic
functions.1) Itactsasa switch turning currenton
and off. 2) It acts as an amplifier. This makes an
output signal that is a magnified version of the
inputsignal.
Integrated Circuits, or ICs, are complex circuits
inside
one
simple
package.
Silicon
and
metals
are
used to simulate resistors, capacitors, transistors,
etc.Itisaspacesavingmiracle.
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ELECTRONICSCHEMATICSYMBOLS
Wiresandconnections
Component CircuitSymbol FunctionofComponent
WireTopasscurrentveryeasilyfromonepartof
acircuittoanother.
Wiresjoined
A'blob'shouldbedrawnwherewiresare
connected(joined),butitissometimes
omitted.Wiresconnectedat'crossroads'
shouldbestaggeredslightlytoformtwoT
junctions,asshownontheright.
Wiresnotjoined
Incomplexdiagramsitisoftennecessaryto
drawwirescrossingeventhoughtheyare
notconnected.Ipreferthe'bridge'symbol
shownontherightbecausethesimple
crossingontheleftmaybemisreadasa
jointwhereyouhaveforgottentoadda
'blob'!
PowerSupplies/Source
Component CircuitSymbol FunctionofComponent
Cell
Supplieselectricalenergy.
Thelargerterminal(ontheleft)ispositive(+).
Asinglecellisoftencalledabattery,but
strictlyabatteryistwoormorecellsjoined
together.
Battery
Supplieselectricalenergy.Abatteryismore
thanonecell.Thelargerterminal(ontheleft)ispositive(+).
DCsupply
Supplieselectricalenergy.
DC=DirectCurrent,alwaysflowinginone
direction.
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ACsupply
Supplieselectricalenergy.
AC=AlternatingCurrent,continuallychanging
direction.
Fuse
Asafetydevicewhichwill'blow'(melt)ifthe
currentflowingthroughitexceedsaspecified
value.
Transformer
Twocoilsofwirelinkedbyanironcore.
Transformersareusedtostepup(increase)
andstepdown(decrease)ACvoltages.Energy
istransferredbetweenthecoilsbythe
magneticfieldinthecore.Thereisnoelectrical
connectionbetweenthecoils.
Earth
(Ground)
Aconnectiontoearth.Formanyelectronic
circuitsthisisthe0V(zerovolts)ofthepower
supply,butformainselectricityandsome
radiocircuitsitreallymeanstheearth.Itisalso
knownasground.
OutputDevices/Loads:Lamps,Heater,Motor
Component CircuitSymbol FunctionofComponent
Lamp(lighting)
Atransducerwhichconvertselectrical
energytolight.Thissymbolisusedfora
lampprovidingillumination,forexamplea
carheadlamportorchbulb.
Lamp(indicator)
Atransducerwhichconvertselectrical
energytolight.Thissymbolisusedfora
lampwhichisanindicator,forexamplea
warninglightonacardashboard.
HeaterAtransducerwhichconvertselectrical
energytoheat.
MotorAtransducerwhichconvertselectrical
energytokineticenergy(motion).
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BellAtransducerwhichconvertselectrical
energytosound.
BuzzerAtransducerwhichconvertselectrical
energytosound.
Inductor
(Coil,Solenoid)
Acoilofwirewhichcreatesamagneticfield
whencurrentpassesthroughit.Itmayhave
anironcoreinsidethecoil.Itcanbeused
asatransducerconvertingelectricalenergy
tomechanicalenergybypullingon
something.
Switches
Component CircuitSymbol FunctionofComponent
PushSwitch
(pushto
make)
Apushswitchallowscurrenttoflowonlywhenthe
buttonispressed.Thisistheswitchusedtooperatea
doorbell.
PushtoBreak
Switch
Thistypeofpushswitchisnormallyclosed(on);itis
open(off)onlywhenthebuttonispressed.
OnOffSwitch
(SPST)
SPST=SinglePole,SingleThrow.
Anonoffswitchallowscurrenttoflowonlywhenit
isintheclosed(on)position.
2waySwitch
(SPDT)
SPDT=SinglePole,DoubleThrow.
A2waychangeoverswitchdirectstheflowof
currenttooneoftworoutesaccordingtoitsposition.
SomeSPDTswitcheshaveacentraloffpositionand
aredescribedas'onoffon'.
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DualOnOff
Switch
(DPST)
DPST=DoublePole,SingleThrow.
Adualonoffswitchwhichisoftenusedtoswitch
mainselectricitybecauseitcanisolateboththelive
andneutralconnections.
Completethetablebelow:
A. Identifyeachofthesesymbols:COMPONENTS SYMBOLS
1.
2.
3.
4.
5.
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B. Identifythefollowingbasicelectroniccomponents
COMPONENT FIGURE
1.
2.
3.
4.
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Asimplecircuitcontainstheminimumthingsneededtohaveafunctioningelectric
circuit
Source adeviceusedtosupplyACorDCvoltage Consuming anydevicethatconsumesvoltage,whatevercomponentorpieceof
equipmentthat isconnectedtoasourceanddrawscurrentfromasource isa
loadonthatsource.
Controlling any device having two states, on (closed) or off (open). Ideallyhavingzeroimpedancewhenclosedandinfiniteimpedancewhenopen.
Protectinga component used to open the circuit when current exceeds apredeterminedmaximumvalue.
Connecting a material that conducts electric current very well and used toconnectacompletepathforcurrent.
ProcedureinCircuitDesigning1. Prepareallthetoolsandmaterialsneeded.2. Byusingschematicsymbol,makeasimplecircuitwiththefollowing:
a. loadb. consumingdevicec. protectingdeviced. consumingdevicee. connectingdevice
3. Make sure that the circuit has the following requirement that asimplecircuitmusthave:
a. Asourceofelectricalpotentialdifferenceorvoltage.b. A conductive path which would allow for the
movementofcharges.
c. Anelectricalresistancewhichislooselydefinedasanyobjectthatuseselectricitytodowork.
4. Test the designed circuit by comparing it with the sample circuitproducedbyyourteacher.
CONTROLLING
CONSUMINGsource
Connectin device
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A.Fillintheblankswithwhatisreferredtobyeachofthefollowing.
1._______________________ Interconnection of components which provides anelectricalpathbetweentwoormorecomponents.
2._______________________ Atypeofcircuitinwhichtheflowofcurrentiscutoff.3._______________________ Acircuitinwhichthecomponentsareconnectedfrom
end to end so that the current hasonlyonepath to
followthroughthecircuit.
4._______________________ A circuit where there is more than one path for thecurrenttoflowthrough.
5._______________________ AdeviceusedtosupplyACorDCvoltage.6._______________________ Anydevicehavingtwostates,ONorOFF.7._______________________ Asafetydeviceusedtoprotectanelectricalcircuit
fromtheeffectofexcessivecurrent.
8._______________________ pathwayforcarryinganelectricalcurrent.9._______________________ Components or pieces of equipment connected to a
source whichdrawscurrentfromasource.
10._______________________ADCvoltagesourcecontainingtwoormorecellsthatconvertchemicalenergytoelectricalenergy.
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A. InitialStepsinUsingAnalogMultitester
1. Connectthetestprobetotheappropriatejack.Theredtestprobetothepositive(+)jackandtheblacktothecommon()jack.
2. Checkifthepointerrestsexactlyattheinfinitezeropositioninohmmeterrange.
COM
(Black)
+POS
(Red)
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3. Checktheprobesiftheyareincondition.(Ohmmetercalibration)a. SettheMultitestertocorrespondingselectorresistancerange.b. Shortthetwotestprobesleadtogether.
ZeroOhm
Adjustment
knob
Note:
Thepointershoulddeflect
towardszeroohmreading
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B. ResistanceMeasurements1. AlwaysdotheInitialStepsinUsingAnalogMultitester.2. In testing resistors, capacitors, diodes etc. do not touch both test probe lead,
because our body also has resistance that could affect the reading value of the
electroniccomponentswearetesting.
3. Ifyoudonotknow thevalueof the resistor tobemeasured, find theohmmeterselectorsettinguntilyouhaveaclearreadingintheohmmeterscale.
Zero
ohm
Adjust the ohm adjustment if the
pointer could not rest exactly at O
ohm reading.
As indicated, the pointer rests out of
the range of ohmmeter scale. Adjust
the ohm adjustment counter
clockwise until the pointer rests O
ohm reading.
OhmmeterSelector
Range
(x1,x10,x1K,x10K
ohms)
Ohm
Adjustment
OhmmeterScale
(FrominfinitetoZero)
InfiniteResistance
openresistorOpen
connectionor
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4. Selectthedesiredresistancerangescalewithselectorswitch.
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Testinga55Kohmresistance
Range:x10Kohm
Thepointerstopsat5.5inx10Krangeonselectorswitch
Testinga55Kohmresistance
Range:x1Kohm
The setting (x1K in 56K Ohm resistor) is not an
advisablesettingintesting55Kohmsresistance.Because,
the pointer stops somewhere in 50. You cannot clearly
readtheresistancevalue,unlikeinx10Kohmsetting.
top related