电路原理课件讲义英文版-Chapter-4

Chapter4CircuitTheorems4.1Introduction4.2LinearityProperty4.3Superposition4.4SourceTransformation4.5Thevenin’sTheorem4.6Norton’sTheorem4.8MaximumPowerTransfer4.1IntroductionSimpleCircuitComplexCircuitBasicLawsBasicAnalysisMethodsSomeTheorems4.2LinearityPropertyAlinearcircuitisonewhoseoutputislinearlyrelated(ordirectlyproportional)toitsinput240I1I2I3I4I12537615sIAExample1FindI0Solution:AssumeI0=1A,anduselinearitytofindtheactualvalueofI001IA10(35)8VIV11/42IVAAtnode1:2103IIIV212214VVIV32/72IVA2415sIA0I1I2I3I4I125376Atnode2:4325IIIV5sIA03IAThus4.3Superposition(迭加)SuperpositionisbasedonlinearityThesuperpositionprinciplestatesthatthevoltageacross(orcurrentthrough)anelementinalinearcircuitisthealgebraicsumofthevoltagesacross(orcurrentsthrough)thatelementduetoeachindependentsourceactingaloneKeepinmind:1.Weconsideroneindependentsourceatatimewhileallotherindependentsourcesareturnedoff(orkilled,madeinactive,deadened,setequaltozero).2.Dependentsourcesareleftintact(完好的)becausetheyarecontrolledbycircuitvariables.StepstoApplySuperpositionPrinciple:1.Turnoffallindependentsourcesexceptonesource.Findtheoutput(voltageorcurrent)duetothatactivesourceusingnodalormeshanalysis.2.Repeatstep1foreachoftheotherindependentsources.3.Findthetotalcontributionbyaddingalgebraicallyallthecontributionsduetotheindependentsources.Assignment1.Solvetheproblems4.7,4.19,4.34inpages155-158