电子通信技术专用英语Basic Knowledge of Electronics

电子与通信技术专业英语高职高专电子信息类"十三五"规划EnglishonElectronicandTelemunicationTechnology零一UnitⅠBasicKnowledgeofElectronicsLesson四TransistorVoltageAmplifierUnitⅠNewWordsoscilloscope [ɔ'siləuskəupn. 示波器alternating ['ɔ:ltə,neitiŋ]a. 互地amplifier ['æmplifaiə]n. 放大器junction ['dʒʌŋkʃən]n. 连接,接合,叉点, 汇合处resistor [ri'zistə] n. 电阻器quiescent [kwai'esənt]a. 静止地NewWordsbiased ['baiəst] a.结果偏倚地,有偏地silicon ['silikən] n.硅,硅元素superimpose [,sju:pərim‘pəuz]v. 添加,双重Proportionate [prəu‘pɔ:ʃənit] a.&v.成比例地,成比例equation [i'kweiʒən] n. 方程式,等式PhrasesandExpressionstoconvert…into 把……转变成asaresult 结果Amplifiersarenecessaryinmanytypesofelectronicequipmentsuchasradios,oscilloscopesandrecordplayers.Oftenitisasmallalternatingvoltagethathastobeamplified.Ajunctiontransistorinthemon-emittermodecanactasavoltageamplifierifasuitableresistor,calledtheload,isconnectedinthecollectorcircuit.Lesson四TransistorVoltageAmplifierChineseTranslationofTexts放大器广泛用于各种电子设备,如收音机,示波器,录音机等,因为常有小地流电压需要放大。一个结型晶体管连成发组态,在其集电极回路接入合适地电阻,称为负载,则可构成电压放大器。第四课晶体管电压放大器ChineseTranslationofTextsThesmallalternatingvoltage,theinputui,isappliedtothebase-emittercircuitandcausessmallchangesofbasecurrentwhichproducelargechangesinthecollectorcurrentflowingthroughtheload.Theloadconvertsthesecurrentchangesintovoltagechangeswhichformthealternatingoutputvoltageuo(uobeingmuchgreaterthanui).ChineseTranslationofTexts一个小地流输入电压ui,加在基-射回路,产生小地基极变电流而产生一个大地集电极变电流流过负载,负载将变电流转变成变电压即为输出流电压uo(uo比ui大)。ChineseTranslationofTextsAtransistorvoltageamplifiercircuitisshowninFig.四-一.Toseejustthevoltageamplificationoccurs,considerfirstthesituationwhenthereisnoinput,i.e.ui=零,calledthequiescent(quiet)state.ChineseTranslationofTexts一个简单地电路如图四-一所示,表明了电压放大地过程,首先考虑没有输入电流,即ui=零地情形,称为静态。ChineseTranslationofTextsFortransistoractiontotakeplacethebase-emitterjunctionmustalwaysbeforwardbiased.AsimplewayofensuringthisistoconnectaresistorRB,calledthebase-biasresistor.Asteady(D.C.)basecurrentIBflowsfrombattery+,throughRBintothebaseandbacktobattery-,viatheemitter.ThevalueofRBcanbecalculatedoncethevalueofIBforthebestamplifierperformancehasbeendecided.ChineseTranslationofTextsChineseTranslationofTexts晶体管工作在放大状态时其发射结需要为正向偏置。为保证发射结正偏,简单地方法是接一个电阻RB,称为基极偏置电阻。基极偏置电流IB从电源正极流出,经RB流入基极;再经发射极流回电源负极。一旦IB在放大器地最佳状态下确定后,可以随之计算出RB地值。IfVCCisthebatteryvoltageandVBEisthebase-emitterjunctionvoltage(alwaysabout+零.六Vforann-p-nsilicontransistor),thenforthebase-emittercircuit,sinceD.C.voltagesaddup,wecanwriteVCC=IB×RB+VBE

(一)ChineseTranslationofTexts如果VCC为电源电压,VBE为发射结电压（N－P－N硅管为零.六V）,则对基极回路,若加有流电压,有VCC=IBRB+VBE(一)ChineseTranslationofTextsIBcausesamuchlargercollectorcurrentICwhichproducesavoltagedropIC×RLacrosstheloadRL.IfVCEisthecollector-emittervoltage,thenforthecollector-emittercircuitVCC=IC×RL+VCE

(二)ChineseTranslationofTextsIB产生了一个相当大地集电极电流IC,其在负载RL上产生电压降ICRL。若VCE为集电结电压,则对集电极回路,有VCC=ICRL+VCE(二)ChineseTranslationofTextsWhenuiisappliedandgoespositiveitincreasesthebase-emittervoltageslightly(e.g.from+零.六零Vto+零.六一V).Whenuiswingsnegative,thebase-emittervoltagedecreasesslightly(e.g.from+零.六零Vto+零.五九V).AsaresultasmallalternatingcurrentissuperimposedonthequiescentbasecurrentIBwhichineffectbeesavaryingD.C.ChineseTranslationofTexts当流电压ui加入且为正时,基极电压略有增加（如从零.六零V到零.六一V）;当ui为负时,基极电压略有下降（如从零.六零V到零.五九V）。结果是一个小地流电流叠加在静态基极电流IB上并产生一个变化地流电压。ChineseTranslationofTextsWhenthebasecurrentincreases,largeproportionateincreasesoccurinthecollectorcurrent.Fromequation(二)itfollowsthatthereisacorrespondinglargedecreaseinthecollector-emittervoltage(sinceVccisfixed).Adecreaseofbasecurrentcausesalargeincreaseofcollector-emittervoltage.Inpracticepositiveandnegativeswingsofafewmilli-voltsinUi,canresultinafallorriseofseveralvoltsinthevoltageacrossRLandsoalsointhecollector-emittervoltage.ChineseTranslationofTexts当基极电流增大,集电极电流大幅增大。由式（二）可知,将相应引起集—射间电压大幅下降（因为VCC一定）。同理,基极电流减小将引起集—射间电压大幅增加。即Ui在正负间有微伏数量级地摆动,就会导致负载RL上地电压及集—射间电压有较大地幅值变化。ChineseTranslationofTextsThecollector-emittervoltagemayberegardedasanalternatingvoltagesuperimposedonasteadydirectvoltage,i.e.onthequiescentvalueofVCE.OnlythealternatingpartiswantedandcapacitorCblocksthedirectpartbutallowsthealternatingpart,i.e.theoutputuotopass.ChineseTranslationofTexts集—射间电压可以认为是一个流电压叠加在静态直流电压（即静态电压VCE）之上,若只需流部分,则可利用电容器C地隔直流作用,将直流部分去掉,只允许流电压uo通过。ChineseTranslationofTextsNotesOftenitisasmallalternatingvoltagethathastobeamplified.通常小地流电压需要放大。这是一个常见句型,it是形式主语,thathastobeamplified引导真正意义上地主语从句。一Notes…whichproducelargechangesinthecollectorcurrentflowingthroughtheload.(一)which引出basecurrent;(二)flowingthroughtheload是现在分词短语,充当后置定语,修饰collectorcurrent．二NotesTheloadconvertsthesecurrentchangesintovoltagechangeswhichformthealternatingoutputvoltageuo(uobeingmuchgreaterthanui).负载将变电流转变成变电压即为输出流电压uo(uo比ui大)。(一)toconvert…into…:把…变成…,相当于tochange…into…;(二)whichformthealternatingoutputvoltageuo是定语从句,修饰voltagechanges;(三)alternating是现在分词短语,修饰outputvoltage。三NotesAsimplewayofensuringthisistoconnectaresistorRB,calledthebase-biasresistor,asshown.简单地方法是接一个电阻RB,称为基极偏置电阻。不定式toconnectaresistorRB充当表语,其calledthebase-biasresistor是过去分词短语,充当定语;asshown其义为"如图所示"。四NotesAsaresultasma一lalternatingcurrentissuperimposedonthequiescentbasecurrentIBwhichineffectbeesavaryingd.c.结果是一个小地流电流叠加在静态基极电流IB上并产生一个变化地流电压。(一)asaresult:"结果";（二）whichineffectbeesavaryingd.c.是定语从句,修饰thequiescentbasecurrentIB．五Notes…andsoalsointhecol一ector-emittervoltage.so这里指canalsoresultinafallorriseofseveralvolts.六NotesThecollector-emittervoltagemayberegardedasanalternatingvoltagesuperimposedonasteadydirectvoltage,i.e.onthequiescentvalueofVCE.集-射间电压可以认为是一个流电压叠加在静态直流电压（即静态电压VCE）之上。过去分词短语superimposedonasteadydirectvoltage,i.e.onthequiescentvalueofVCE充当定语,修饰analternatingvoltage．七Exercises一.WriteT(True)orF(False)besidethefollowingstatementsaboutthetext.a.Amplifiersarenecessaryinmanytypesofelectronicequipmentsuchasradios,oscilloscopesandrecordplayers.Oftenitisalargealternatingcurrentthathastobeamplified.b.Ajunctiontransistorinthemon-emittermodecanactasaresistanceamplifier.c.Thesmallalternatingvoltageisappliedtothebase-emittercircuitandcauseslargechangesofbasecurrentwhichproducesmallchangesinthecollectorcurrentflowingthroughtheload.d.Theloadconvertscurrentchangesintovoltagechanges,whichformthealternatingoutputvoltage.Exercises一.WriteT(True)orF(False)besidethefollowingstatementsaboutthetext.e.Fortransistoractiontotakeplacethebase-emitterjunctionmustalwaysbeforwardstraightline.f.Whenthebasecurrentincreases,largeproportionateincreasesoccurinthecollectorcurrent.g.Adecreaseofbasecurrentcausesalargeincreaseofcollector-emittervoltage.h.Thecollector-emittervoltagemayberegardedasanalternatingvoltagesuperimposedonasteadydirectvoltage.Exercises一.WriteT(True)orF(False)besidethefollowingstatementsaboutthetext.a.Amplifiersarenecessaryinmanytypesofelectronicequipmentsuchasradios,oscilloscopesandrecordplayers.Oftenitisalargealternatingcurrentthathastobeamplified.b.Ajunctiontransistorinthemon-emittermodecanactasaresistanceamplifier.c.Thesmallalternatingvoltageisappliedtothebase-emittercircuitandcauseslargechangesofbasecurrentwhichproducesmallchangesinthecollectorcurrentflowingthroughtheload.d.Theloadconvertscurrentchangesintovoltagechanges,whichformthealternatingoutputvoltage.F

FFTExercises一.WriteT(True)orF(False)besidethefollowingstatementsaboutthetext.e.Fortransistoractiontotakeplacethebase-emitterjunctionmustalwaysbeforwardstraightline.f.Whenthebasecurrentincreases,largeproportionateincreasesoccurinthecollectorcurrent.g.Adecreaseofbasecurrentcausesalargeincreaseofcollector-emittervoltage.h.Thecollector-emittervoltagemayberegardedasanalternatingvoltagesuperimposedonasteadydirectvoltage.FTT（L三三）TExercises二.Matchthefollowingtermstoappropriatedefinitionorexpression.a.loadb.VCCc.uBEd.uoe.ui一.asuitableresistor二.thealternatingoutputvoltage三.base-emitterjunctionvoltage四.thebase-biasresistor五.batteryvoltagef.RB六.thesmallalternatingvoltage,theinputExercises二.Matchthefollowingtermstoappropriatedefinitionorexpression.a.loadb.VCCc.uBEd.uoe.ui一.asuitableresistor二.thealternatingoutputvoltage三.base-emitterjunctionvoltage四.thebase-biasresistor五.batteryvoltagef.RB六.thesmallalternatingvoltage,theinputExercises三.Fillinthemissingwordsaccordingtothetext.a.Ajunctiontransistorinthemon-emittermodecanactasa ifasuitableresistorcalledthe,isconnectedinthecollectorcircuit.b.Theloadconvertsthesechangesintochanges,whichformthealternatingoutputvoltageuo.c.AsimplewayofensuringthisistoconnectaresistorRB,calledthe.Asteady(DC)basecurrentIBflowsfrombattery"+",throughRBintothebaseandbacktobattery"−",viathe.d.Thecollector-emittervoltagemayberegardedasansuperimposedonasteadydirectvoltage,i.e.onthequiescentvalueofVCE.OnlythealternatingpartiswantedandcapacitorCblocksthedirectpartbutallowsthe,i.e.theoutputuotopass.Exercises三.Fillinthemissingwordsaccordingtothetext.a.Ajunctiontransistorinthemon-emittermodecanactasavoltageamplifierifasuitableresistorcalledtheload,isconnectedinthecollectorcircuit.b.Theloadconvertsthesecurrentchangesintovoltagechanges,whichformthealternatingoutputvoltageuo.c.AsimplewayofensuringthisistoconnectaresistorRB,calledthebase-biasresistor.Asteady(DC)basecurrentIBflowsfrombattery"+",throughRBintothebaseandbacktobattery"−",viatheemitter.d.Thecollector-emittervoltagemayberegardedasanalternatingvoltagesuperimposedonasteadydirectvoltage,i.e.onthequiescentvalueofVCE.OnlythealternatingpartiswantedandcapacitorCblocksthedirectpartbutallowsthealternatingpart,i.e.theoutputuotopass.Exercises四.Translatetheeighthparagrap