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1、Chapter1ElectricandElectronicTechnologyFundamentalsUnit3TransistorTextNewWordsandExpressionsExercisesEndProcessofTranslationUnit3TransistorAtransistorisasemiconductordeviceusedtoamplifyandswitchelectronicsignals.Itismadeofasolidpieceofsemiconductormat
2、erial,withatleastthreeterminalsforconnectiontoanexternalcircuit.Avoltageorcurrentappliedtoonepairofthetransistor'sterminalschangesthecurrentflowingthroughanotherpairofterminals.Becausethecontrolled(output)powercanbemuchmorethanthecontrolling(input)pow
3、er,thetransistorprovidesamplificationofasignal.Today,sometransistorsarepackagedindividually,butmanymorearefoundembeddedinintegratedcircuits.Thetransistoristhefundamentalbuildingblockofmodernelectronicdevices,andisubiquitousinmodernelectronicsystems.Fo
4、llowingitsreleaseintheearly1950sthetransistorrevolutionisedthefieldofelectronics,andpavedthewayforsmallerandcheaperradios,calculators,andcomputers,amongstotherthings.Unit3TransistorImportanceThetransistoristhekeyactivecomponentinpracticallyallmodernel
5、ectronics,andisconsideredbymanytobeoneofthegreatestinventionsofthetwentiethcentury.Itsimportanceintoday'ssocietyrestsonitsabilitytobemassproducedusingahighlyautomatedprocess(semiconductordevicefabrication)thatachievesastonishinglylowper-transistorcost
6、s.Unit3TransistorUnit3TransistorAlthoughseveralcompanieseachproduceoverabillionindividuallypackaged(knownasdiscrete)transistorseveryyear,thevastmajorityoftransistorsnowproducedareinintegratedcircuits(oftenshortenedtoIC,microchipsorsimplychips),alongwi
7、thdiodes,resistors,capacitorsandotherelectroniccomponents,toproducecompleteelectroniccircuits.Alogicgateconsistsofuptoabouttwentytransistorswhereasanadvancedmicroprocessor,asof2009,canuseasmanyas2.3billiontransistors(MOSFETs)."About60milliontransistor
8、swerebuiltthisyear[2002]...for[each]man,woman,andchildonEarth."Thetransistor'slowcost,flexibility,andreliabilityhavemadeitaubiquitousdevice.Transistorizedmechatroniccircuitshavereplacedelectromechanicaldevicesincontrollingappliancesandmachiner
