《電氣工程原理與應(yīng)用》配套教學課件

電路與模擬電子技術(shù)CircuitsandAnalogElectronicsftp服務(wù)電路與模擬電子技術(shù)主要參考書1.PrinciplesAndApplicationsOfElectricalEngineering

作者：GiorgioRizzoniISBN:7-5053-9944-6(電氣工程原理與應(yīng)用喬治.里佐尼著郭福田等譯電子工業(yè)出版社)2.電路與模擬電子技術(shù)高玉良高教出版社3.EngineeringCircuitAnalysis.6nd,WilliamH.Hayt.李春茂改編

ElectronicDevicesandCircuitTheory.9nd,RobertL.Boylestad,LouisNashelsky李立華改編電子工業(yè)出版社Circuits

Thebasicprinciplesofcircuitanalysis,introductiontothecurrent,voltage,power,circuitelements,Ohm'slaw,Kirchhoff'scurrentandvoltagelaws,Superposition,andEquivalencetheorems,Transientanalysis,ACsteady-stateanalysis.AnalogElectronics

Basicphysicalmodelsoftheoperationofsemiconductordevicessuchasdiodes,bipolarjunctiontransistors，OPAmp，andterminalcurrent-voltagecharacteristicsofthecomponents，Analyzingsimplediodecircuitsandtransistoramplifiercircuits,OpAmpCircuits，includingcircuitdesign.CircuitsandAnalogElectronicsCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuits1.2

BasicQuantities1.3

CircuitElements

1.4

Kirchhoff'sCurrentandVoltageLaws

Readings:Ch2CircuitsandAnalogElectronicsCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsKeyWords:

LumpedCircuitAbstraction

CircuitsSystem

SignalprocessingandtransmissionAmplifiers1.1

BasicConceptsandElectricCircuitsCh1BasicConceptsandLawsofElectricCircuitsElectricalpowerconversionandtransmissionPowerSupplies

TransmissionLoadsCircuitsKinescopeAntennaSpeakertransmitterCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsSupposewewishtoanswerthisquestion:Whatisthecurrentthroughthebulb?Ch1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsRrepresentstheonlypropertyofinterest!

Risalumpedelementabstractionforthebulb.Then,wecanreplacethebulbwitharesistorforthepurposeofcalculatingthecurrent.Indoingso,youignoredtheobject’sshape，itstemperature，itscolor，pointofforce.Ch1BasicConceptsandLawsofElectricCircuitsAresistorisacircuitelementthatdissipateselectricalenergy(usuallyasheat).Real-worlddevicesthataremodeledbyresistors:incandescentlightbulb,heatingelements(stoves,heaters,etc.),longwires1.1

BasicConceptsandElectricCircuitscalledelementv-irelationshipLumpedcircuitabstraction!Acircuitiscomposedofelements(sources,resistors,capacitors,inductors)andconductors(wires).Elementsarelumped.Conductorsareperfect.1=1V/AG=1/RistheconductanceinSiemens(S)i(t)=Gv(t)1S=1A/VCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsUnderstandingtheAMradiorequiresknowledgeofseveralEEsubdisciplines:--Communications/signalprocessing(frequencydomainanalysis)--Electromagnetics(antennas,high-frequencycircuits)--Power(batteries,powersupplies)--Solidstate(miniaturization,low-powerelectronics)TheAMRadio“System”Ch1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTransmitterReceiverTheAMRadio“System”Ch1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Asignalisaquantitythatmayvarywithtime.--Voltageorcurrentinacircuit--Sound(pressurewavetravelingthroughair)--Lightorradiowaves(electromagneticenergytravelingthroughfreespace)TheanalysisanddesignofAMradios(andcommunicationsystemsingeneral)isusuallyconductedinthefrequencydomainusingFourieranalysis.Fourieranalysisallowsustorepresentsignalsascombinationsofsinusoids(sinesandcosines).Ch1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Frequencyistherateatwhichasignaloscillates.HighFrequencyLowFrequencyCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Visiblelightiselectromagneticenergywithfrequencybetween380THz(Terahertz)and860THz.Ourvisualsystemperceivesthefrequencyoftheelectromagneticenergyascolor.Redis460THz,greenis570THz,andblueis630THz.AnAMradiosignalhasafrequencyofbetween500kHzand1.8MHz.FMradioandTVusesdifferentfrequencies.MathematicalanalysisofsignalsintermsoffrequencyMostcommonlyencounteredsignalscanberepresentedasaFourierseriesoraFouriertransform.AFourierseriesisaweightedsumofcosinesandsines.Ch1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Example-FourierSeriesSquarewaveFourierSeriesrepresentationofthesquarewaveCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Example-FourierSeriesCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Signalscanberepresentedintermsoftheirfrequencycomponents.TheAMtransmitterandreceiverareanalyzedintermsoftheireffectsonthefrequencycomponentssignals.SignalSourceModulatorPowerAmplifierAntennaTransmitterBlockDiagramCh1BasicConceptsandLawsofElectricCircuitsThemodulatorconvertsthefrequencyoftheinputsignalfromtheaudiorange(0-5kHz)tothecarrierfrequencyofthestation(i.e..605kHz-615kHz)1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”frequency5kHzFrequencydomainrepresentationofinputFrequencydomainrepresentationofoutputfrequency610kHzModulator調(diào)制器Ch1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”InputSignalOutputSignalModulator-TimeDomainCh1BasicConceptsandLawsofElectricCircuitsAtypicalAMstationbroadcastsseveralkWUpto50kW-ClassIorclassIIstationsUpto5kW-ClassIIIstationUpto1kW-ClassIVstationTypicalmodulatorcircuitcanprovideatmostafewmWPoweramplifiertakesmodulatoroutputandincreasesitsmagnitude1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”PowerAmplifier功率放大Theantennaconvertsacurrentoravoltagesignaltoanelectromagneticsignalwhichisradiatedthroughoutspace.AntennaCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”RFAmplifierIFMixerIFAmplifierEnvelopeDetectorAudioAmplifierAntennaSpeakerReceiverBlockDiagramCh1BasicConceptsandLawsofElectricCircuitsTheantennacaptureselectromagneticenergy-itsoutputisasmallvoltageorcurrent.Inthefrequencydomain,theantennaoutputis

1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”0frequencyUndesiredSignalsDesiredSignalCarrierFrequencyofdesiredstationAntennaCh1BasicConceptsandLawsofElectricCircuitsRFstandsforradiofrequency.RFAmplifieramplifiessmallsignalsfromtheantennatovoltagelevelsappropriatefortransistorcircuits.RFAmplifieralsoperformsabandpassfilteroperationonthesignalBandpassfilterattenuatesthefrequencycomponentsoutsidethefrequencybandcontainingthedesiredstation1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”RFAmplifierFrequenciesoutsidethedesiredfrequencybandareattenuatedFrequencydomainrepresentationoftheoutput:RFAmplifier-FrequencyDomain0frequencyUndesiredSignalsDesiredSignalCarrierFrequencyofdesiredstationCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”TheIFMixershiftsitsinputinthefrequencydomainfromthecarrierfrequencytoanintermediatefrequencyof455kHzIFMixer0frequencyUndesiredSignalsDesiredSignal455kHzCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”TheIFamplifierbandpassfilterstheoutputoftheIFMixer,eliminatingessentiallyalloftheundesiredsignals.IFAmplifier0frequencyDesiredSignal455kHzCh1BasicConceptsandLawsofElectricCircuitsComputestheenvelopeofitsinputsignal1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”EnvelopeDetectorOutputSignalInputSignalCh1BasicConceptsandLawsofElectricCircuitsAmplifiessignalfromenvelopedetectorProvidespowertodrivethespeaker1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”AudioAmplifierCh1BasicConceptsandLawsofElectricCircuitsHierarchicalmodeling(程序化建模）ismodelingatdifferentlevelsofabstractionHigherlevelsofthemodeldescribeoverallfunctionofthesystemLowerlevelsofthemodeldescribedetailnecessarytoimplementthesystem1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”HierarchicalSystemModelsIntheAMreceiver,theinputistheantennavoltageandtheoutputisthesoundenergyproducedbythespeaker.InEE,asystemisanelectricaland/ormechanicaldevice,aprocess,oramathematicalmodelthatrelatesoneormoreinputstooneormoreoutputs.SystemInputsOutputsCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”TopLevelModelAMReceiverInputSignalSoundCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”SecondLevelModelRFAmplifierIFMixerIFAmplifierEnvelopeDetectorAudioAmplifierAntennaSpeakerPowerSupplyCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheAMRadio“System”Half-waveRectifier半波整流Low-passFilter低通濾波LowLevelModelEnvelopeDetector.CircuitLevelModelEnvelopeDetector+-RC+-VoutVinCh1BasicConceptsandLawsofElectricCircuitsThemoderntelephonesystemdrawsfromtheseElectricalEngineeringsubdisciplines:Signalprocessing:Speechcompression,noisereduction,A/DandD/Aconversion..Communicationsandnetworking:transmissiontechnologies,networkarchitecturesandprotocols.Digitalandcomputer:configurableswitchinghardware.Electromagnetics:microwavetransmission

hardware.Solidstate:miniaturization,integrationofcomplexsystemsontoasinglechip.PowerElectronics:extremelyreliablepowersupplies.1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemAnEarlyPhoneSystemTelephoneTelephoneSpeakerMic.TelephoneSpeakerMic.CentralOfficeSwitchboardSpeakerMic.PowerSupplyCh1BasicConceptsandLawsofElectricCircuitsThemajorcomponentsofatelephonewereacarbonmicrophoneandaspeakermadefromanelectromagnetandaparamagneticdiaphragm.Telephoneswereconnectedtothecentralofficebytwisted-pairwires.Atthecentraloffice,callswerecompletedbyahumanoperatorataswitchboard-aphysicalconnectionbetweentwotelephoneswasmade.1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemAnEarlyPhoneSystemCh1BasicConceptsandLawsofElectricCircuits1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemAnEarlyPhoneCircuitTelephoneHandsetCarbonMicrophoneEarphoneCentralOfficeBatteryTelephoneHandsetCarbonMicrophoneEarphoneElectricalcurrentflowsinthiscircuitinaloopfromthebatteryatthecentraloffice,throughthecomponentsofthetwotelephones(thespeakerandthemicrophone),andbackintothebattery.Thiscircuitisaseriesconnectionofthecomponentsinthetwotelephonesandthebattery.Allofthecurrentthatflowsthroughthebatteryalsoflowsthroughthecomponentsinthetwotelephones.Ch1BasicConceptsandLawsofElectricCircuitsFundamentally,themoderntelephonesystemsappearsmuchthesameastheearlysystemtohandsetusers.Thereareverysignificantdifferences:Digitaldata,video,andothersignalsaretransmittedalongwithspeech.Callsareroutedautomaticallyundersoftwarecontrol.Mosttransmissionisdigital.1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemTheModernTelephoneSystemPCMEncoderPCMDecoderSwitchingNetworkPCMDecoderPCMEncoderAnalogAnalogDigitalCh1BasicConceptsandLawsofElectricCircuitsAnanalogsignalisacontinuous-timesignal:1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemAnalogVs.DigitalAdigitalsignalisasequenceof1’sand0’s:1101001010011100100110001001110timeCh1BasicConceptsandLawsofElectricCircuitsTransmissionoverlongdistancesdegradesbothanaloganddigitalsignalscanbe“cleanedup”,allowingrepeaterstobeusedwithoutanysignaldistortion.Canmixmanytypesofinformation(phone,video,data,etc.)Digitalhardwareislessexpensive.Digitaldatacanbeencrypted.1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemWhyDigital?Ch1BasicConceptsandLawsofElectricCircuitsAPCMencoderconvertsananalogsignalintoadigitalsignalwithaparticularformat.APCMdecoderconvertsadigitalsignalintoananalogsignal.PCMisoneformofquantization.PCMisoneformofanalog-to-digital(A/D)conversion.1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemPCM-PulseCodeModulationCh1BasicConceptsandLawsofElectricCircuitsAcontinuoussignalisconvertedintoabitstream:1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemPCM-PulseCodeModulationPCMEncoder0000010100000000111111Involvesthreeoperations:Sampling,Quantization,andEncodingCh1BasicConceptsandLawsofElectricCircuitsValueofthesignalisobtainedatequallyspacedpointsintime:1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemPCM-PulseCodeModulationSamplingtimePCMEncoderCh1BasicConceptsandLawsofElectricCircuitsEachsampleisquantizedtooneofafinitenumberofvalues.Quantizerinput/outputrelationship:1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemPCM-PulseCodeModulationQuantizerinputvoltageoutputvoltagePCMEncoderCh1BasicConceptsandLawsofElectricCircuitsApatternofbitsisassignedtoeachpossibleoutputlevelofthequantizer.nbitscanrepresent2nquantizeroutputlevels.1.1

BasicConceptsandElectricCircuitsTheTelephoneSystemPCM-PulseCodeModulationEncodingPCMdecoderisonetypeofdigital-to-analog(D/A)converter.PCMEncoder0000010100000000111111Ch1BasicConceptsandLawsofElectricCircuitsAhouseorbusinessiscalledasubscriber.Typically,phonelinestohousesorsmallbusinessesareanalogtwisted-pairwireconnections.Subscribers’analoglinesareconnectedtoaRegionalTerminal(RT)ortoaCentralOffice(CO).AttheRTorCO,theanalogsignalisconvertedtoadigitalsignal.1.1

BasicConceptsandElectricCircuitsTelephoneNetworkTheTelephoneSystemSubscriberSubscriberRTSubscriberSubscriberRTCOLong-distanceNetworkCh1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesKeyWords:

current,voltage,powerandenergy

Ch1BasicConceptsandLawsofElectricCircuitsStandardSIPrefixes10-12pico(p)10-9nano(n)10-6micro()10-3milli(m)103kilo(k)106mega(M)109giga(G)1012tera(T)1.2

BasicQuantitiesUnitsElectriccharge(q)inCoulombs(C)Current(I)inAmperes(A)Voltage(V)inVolts(V)Energy(W)inJoules(J)Power(P)inWatts(W)Ch1BasicConceptsandLawsofElectricCircuitsTimerateofchangeofcharge1.2

BasicQuantities基本物理量Current電流ConstantcurrentTimevaryingcurrentNotation:CurrentflowrepresentstheflowofpositivechargeAlternatingversusdirectcurrent(ACvsDC)Unit(1A=1C/s)Ch1BasicConceptsandLawsofElectricCircuitsTimerateofchangeofcharge1.2

BasicQuantitiesCurrentConstantcurrentTimevaryingcurrentNotation:CurrentflowrepresentstheflowofpositivechargeAlternatingversusdirectcurrent(ACvsDC)Unit(1A=1C/s)Ch1BasicConceptsandLawsofElectricCircuitsP1.1,Inthewireelectronsmovinglefttorighttocreateacurrentof1mA.DetermineI1andI2.1.2

BasicQuantitiesCurrentPositiveversusnegativecurrent2A-2AAns:I1

=-1mA;I2=+1mA.Ch1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesVoltage(Potential)VoltageUnits:1V=1J/CPositiveversusnegativevoltage+––+2V-2VCh1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesVoltage(Potential)P1.2,aba、b,whichpoint’spotentialishigher？

baVab=?ab+Qfrompointbtopointagetenergy，PointaisPositive?ornegative?Ch1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesVoltage(Potential)P1.3,abc′cdd′Vab=Va-Vb=VaICh1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesVoltage(Potential)P1.4,KOpenKCloseVa=?IICh1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesCh1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesCh1BasicConceptsandLawsofElectricCircuitsRateofchangeofenergy1.2

BasicQuantitiesPowerP=W/tUsedtodeterminetheelectricalpowerisbeingabsorbedorsuppliedifPispositive(+),powerisabsorbedifPisnegative(–),powerissupplied+–v(t)i(t)p(t)=v(t)i(t)v(t)isdefinedasthevoltagewithpositivereferenceatthesameterminalthatthecurrenti(t)isentering.Ch1BasicConceptsandLawsofElectricCircuitsPowerabsorbedbyaresistor:1.2

BasicQuantitiesPowerCh1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesPower12345I1I2I3+-----++++-++-+-P1.5Findthepowerabsorbedbyeachelementinthecircuit.Ch1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesOpenCircuitR=I=0,V=E,P=0ER0ShortCircuitR=0ER0R＝0Ch1BasicConceptsandLawsofElectricCircuits1.2

BasicQuantitiesLoadedCircuitER0RICh1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsKeyWords:

Resistors,Capacitors,Inductors

voltagesource,currentsource

Ch1BasicConceptsandLawsofElectricCircuitsPassiveelements(cannotgenerateenergy)e.g.,resistors,capacitors,inductors,etc.Activeelements(capableofgeneratingenergy)batteries,generators,etc.ImportantactiveelementsIndependentvoltagesourceIndependentcurrentsourceDependentvoltagesourcevoltagedependentandcurrentdependentDependentcurrentsourcevoltagedependentandcurrentdependent1.3

CircuitElementsCh1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsResistorsDissipationElements

v=iR

P=vi=Ri2=v2/R>0，

v-irelationshipviResistorsconnectedinseries:EquivalentResistanceisfoundbyReq=R1+R2+R3+…Resistorsconnectedinparallel1/Req=1/R1+1/R2+1/R3+…Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsCapacitorsCapacitanceoccurswhentwoconductors(plates)areseparatedbyadielectric(insulator).Chargeonthetwoconductorscreatesanelectricfieldthatstoresenergy.Thevoltagedifferencebetweenthetwoconductorsisproportionaltothecharge:q=CvTheproportionalityconstantCiscalledcapacitance.UnitsofFarads(F)-C/V1F=106F,1F=106pF

Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsCapacitors

storeenergyinanelectricfieldv-irelationshipi(t)+-v(t)TherestofthecircuitCapacitorsconnectedinseries:Equivalentcapacitanceisfoundby1/Ceq=1/C1+1/C2+1/C3+…CapacitorsconnectedinparallelCeq=C1+C2+C3+…Energystored

Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsCapacitorsti(t)1A-1A1s2si(t)+-v(t)Therestofthecircuit0.2Ftv(t)5V1s2stw

(t)2.5J1s2sP1.7Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsInductors

storeenergyinamagneticfieldv-irelationshipi(t)+-v(t)TherestofthecircuitLEnergystored:

Inductorsconnectedinseries:Leq=L1+L2+L3+…Inductorsconnectedinparallel:1/Leq=1/L1+1/L2+1/L3+…Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsIndependentvoltage

source+VSRS＝0viVSIdealpracticalCh1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsIndependentcurrent

sourceIviISRS＝IdealpracticalCh1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsVoltagesourceconnectedinseries:Currentsourceconnectedinparallel:Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsVoltagecontrolled(dependent)voltagesource(VCVS)+__+Currentcontrolled(dependent)voltagesource(CCVS)+_Q:Whataretheunitsforandr?Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsVoltagecontrolled(dependent)currentsource(VCCS)Currentcontrolled(dependent)currentsource(CCCS)_+Q:Whataretheunitsforandg?Ch1BasicConceptsandLawsofElectricCircuits1.3

CircuitElementsIndependentsourcedependentsourceCanprovidepowertothecircuit;Excitationtocircuit

;Outputisnotcontroledbyexternal.Canprovidepowertothecircuit;

Noexcitationto

circuit;Outputiscontroledbyexternal.Ch1BasicConceptsandLawsofElectricCircuitsSofar,wehavetalkedabouttwokindsofcircuitelements:Sources(independentanddependent)active,canprovidepowertothecircuit.Resistorspassive,canonlydissipatepower.1.3

CircuitElementsReviewTheenergysuppliedbytheactiveelementsisequivalenttotheenergyabsorbedbythepassiveelements!Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KeyWords:

Nodes,Branches,LoopsKCL,KVL

Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

Nodes,Branches,Loops,meshNode:pointwheretwo,ormore,elementsarejoined(e.g.,bignode1)Loop:Aclosedpaththatnevergoestwiceoveranode(e.g.,theblueline)Branch:Componentconnectedbetweentwonodes(e.g.,componentR4)TheredpathisNOTaloopMesh:Aloopthatdoesnotcontainanyotherloopsinit.Ch1BasicConceptsandLawsofElectricCircuitsAcircuitcontainingthreenodesandfivebranches.Node1isredrawntolookliketwonodes;itisstillonenodes.1.4

Kirchhoff'sCurrentandVoltageLaws

Nodes,Branches,Loops,meshP1.8Ch1BasicConceptsandLawsofElectricCircuitssumofallcurrentsenteringanodeiszerosumofcurrentsenteringnodeisequaltosumofcurrentsleavingnode1.4

Kirchhoff'sCurrentandVoltageLaws

KCLKCLMathematicallyi1(t)i2(t)i4(t)i5(t)i3(t)Ch1BasicConceptsandLawsofElectricCircuitssumofallcurrentsenteringanodeiszerosumofcurrentsenteringnodeisequaltosumofcurrentsleavingnode1.4

Kirchhoff'sCurrentandVoltageLaws

KCLP1.9Ch1BasicConceptsandLawsofElectricCircuitsFindcurrentsthrougheachlightbulb:IB=1W/120V=8.3mAApplyKCLtothetopnode:IS-50IB

=0SolveforIS:IS=50IB=417mA1.4

Kirchhoff'sCurrentandVoltageLaws

KCL+-120V50*1WBulbsIsP1.10KCL-ChristmasLightsCh1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KCLP1.11Wecanmakesupernodesbyaggregtingnode.Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KCLP1.12FindixCh1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KCLCurrentdividerNVR1R2I+-I1I2Ch1BasicConceptsandLawsofElectricCircuitssumofvoltagesaroundanyloopinacircuitiszero.1.4

Kirchhoff'sCurrentandVoltageLaws

KVLAvoltageencountered+to-ispositive.Avoltageencountered-to+isnegative.KVLMathematicallyCh1BasicConceptsandLawsofElectricCircuitsKVLisaconservationofenergyprinciple1.4

Kirchhoff'sCurrentandVoltageLaws

KVLApositivechargegainselectricalenergyasitmovestoapointwithhighervoltageandreleaseselectricalenergyifitmovestoapointwithlowervoltageIfthechargecomesbacktothesameInitialpointthenetenergygainMustbezero.Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLP1.13Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLP1.13Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLVoltagedividerR1R2-V1++-V2+-VImportantvoltageDividerquationsNCh1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLVoltagedividerVolumecontrol?P1.14Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLP1.15I2I3I1HowdowefindI1andI2,I3,?Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLP1.16CURRENTCONTROLLEDVOLTAGESOURCEIo=?Ch1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLiBCh1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVLI3I2I1+-VCh1BasicConceptsandLawsofElectricCircuits1.4

Kirchhoff'sCurrentandVoltageLaws

KVL2.2UsefulCircuitAnalysisTechniquesCh2BasicAnalysisMethodstoCircuitsMesh(Loop)AnalysisDEPENDENTCURRENTSOURCE.CURRENTSOURCESNOTSHAREDBYMESHESWetreatthedependentsourceasaconventionalsourceThenKVLontheremainingloop(s)Andexpressthecontrollingvariable,Vx,intermsofloopcurrentsEquationsformesheswithcurrentsourcesWEAREASKEDFORVo.WEONLYNEEDTOSOLVEFORI3REPLACEANDREARRANGECh1BasicConcepts