电工与电子技术

朽木易折，金石可镂。千里之行，始于足下。第页/共页ElectrotechnicsBasictheoremandcomputedmethodofDCcircuits,phasevalueofsinusoidalandresonate,computationofbalancedthree-phaseACcircuits,transientanalysisandcomputationoffirst-ordercircuit,structureandprincipleoftransformer,basicstructureandprincipleofthree-phaseinductionmotors.Thiscourseintroducessomebasicconceptionsandprinciples,suchastheOhmlaw,theKirchhoff’scurrentlawandvoltagelaw.Thesecontentsarefundamentalofanalyzingorcalculatingacircuit.Andifthecircuitisalittlebitmorecomplex,thiscoursealsoteachesussomeothermethodstoreduce(simplify)oranalyzethecircuit,suchastheequivalentcircuittransformation(等效变换),superpositionprinciple（叠加原理）,Thevenin’stheorem(戴维宁定理),Norton’stheorem(诺顿定理),thesearealsobasicmethodstoanalyzeacircuit.Wealsotalksomethingaboutthemotor,forexampletheACmotorandtheDCmotorandtheDCmotorismostlyusedinthevehicle.Inelectronicpart,theteacherintroducedsomeknowledgeabouttheSemi-conductordiodeandtriodeCavity（空穴）andelectrongeneratedbyexternalvoltagemove,thereforeresultingcurrentsTheBasis,theEmissionandtheCollector.Ie=Ic=IbAndsomecircuitwhichiscomposedbythesemi-conductorssuchastheamplifyingcircuit.Wealsolearntsomethingaboutthegatecircuitwhichiscomposedbythreecomponents:andgate,orgateandnogate.基尔霍夫定律（KirchhoffCircuitLaws）Kirchhoff’sCurrentLaw1)Atanynode(junction)inan

\o"Electricalcircuit"electricalcircuit,thesumof

\o"Current(electricity)"currents

flowingintothatnodeisequaltothesumofcurrentsflowingoutofthatnode,or,thealgebraicsumofcurrentsinanetworkofconductorsmeetingatapointiszero.Kirchhoff’sVoltageLaw2)Thedirectedsumoftheelectrical

\o"Potentialdifference"potentialdifferences

(voltage)aroundanyclosednetworkiszero,or,thesumofthe

\o"Electromotiveforce"emfs

(electromotiveforces)inanyclosedloopisequivalenttothesumofthepotentialdropsinthatloop.Theequivalentcircuittransformation(等效变换):Theequaltransferofresistance’sshuntconnectionandseriesconnectionTheequaltransferbetweenvoltageandcurrentpowerIs=E/RorE=RIsSuperpositionprinciple(叠加定理):Foralinearsystemtheresponse(\o"Voltage"Voltage

or

\o"Electriccurrent"Current)inanybranchofabilaterallinearcircuithavingmorethanoneindependentsourceequalsthealgebraicsumoftheresponsescausedbyeachindependentsourceactingalone,whileallotherindependentsourcesarereplacedbytheirinternal

\o"Electricalimpedance"impedances.Toascertainthecontributionofeachindividualsource,alloftheothersourcesfirstmustbe"turnedoff"(settozero)by:Replacingallotherindependent

\o"Voltagesource"voltagesources

witha

\o"Shortcircuit"shortcircuit

(therebyeliminatingdifferenceofpotential.i.e.V=0,internalimpedanceofideal

\o"Voltagesource"voltagesource

isZERO(\o"Shortcircuit"shortcircuit)).Replacingallotherindependent

\o"Currentsource"currentsources

withan

\o"Opencircuit"opencircuit

(therebyeliminatingcurrent.i.e.I=0,internalimpedanceofideal

\o"Currentsource"currentsource

isinfinite(\o"Opencircuit"opencircuit)).戴维宁定理和诺顿定理(Thevenin’stheoremandNorton’stheorem)Anycombinationof

\o"Voltagesource"voltagesources,

\o"Currentsource"currentsources,and

\o"Resistor"resistors

withtwoterminalsiselectricallyequivalenttoasinglevoltagesource

V

andasingleseriesresistor

R.任何一个线性有源二端口网络对于外部电路来说，总可以用一个电压源和电阻的串联来等效替代。Anycollectionof

\o"Voltagesource"voltagesources,

\o"Currentsource"currentsources,and

\o"Resistor"resistors

withtwoterminalsiselectricallyequivalenttoanidealcurrentsource,

I,inparallelwithasingleresistor,

R.任何一个线性有源二端口网络对于外部电路来说，总可以用一个电流源和电阻的并联来等效替代。Electronictechnology电子技术Triode’sfunctionisamplification.Diodehasone-wayconductivity.positive正极negative负极voltage电压

NPN：Nisthataddphosphorus磷inhighpuritysilicon高纯度硅Pisthataddboron硼inhighpuritysilicon

电子electron空穴holetriode三极管diode二极管transistor晶体管Electronictechnologyexperiment电子技术实验Thiscourserelatedtoanothercoursecalledelectronictechnology.Theexperimentisthatweshould