電氣工程及其自動(dòng)化專業(yè)英語(yǔ)

Chapter1CircuitFundamentals電路基礎(chǔ)1.內(nèi)容簡(jiǎn)介

本章主要介紹電荷；導(dǎo)體、絕緣體、半導(dǎo)體；電流、電壓、電阻的概念；電阻、電壓、電流的測(cè)試方法；直流串聯(lián)電路和交流電路基本原理等內(nèi)容。2.文中涉及理論知識(shí)可參考《電路》中有關(guān)內(nèi)容。3.生詞與短語(yǔ)1．electrostaticadj.靜電的2．chargen.電荷3．positiveadj.正的4．negativeadj.負(fù)的5．electronn.電子6．protonn.質(zhì)子7．gravitationaladj.引力的8．precipitatorn.電濾器9．powerplant發(fā)電廠10.currentn.電流11．conductorn.導(dǎo)體12．insulatorn.絕緣體13．semiconductorn.半導(dǎo)體14．valenceshell價(jià)電子層

Chapter1CircuitFundamentals15．Siliconn.硅16．germaniumn.鍺17．seleniumn.硒18．voltagen.電壓19．resistancen.電阻20．circuitn.電路21．electromotiveforce(EMF)電動(dòng)勢(shì)22．repelv.排斥23．multimetern.萬(wàn)用表24．milliammetern.毫安表

Chapter1CircuitFundamentals25．a(chǎn)mmetern.安培表26．ohmmetern.歐姆表27．voltmetern.電壓表28．polarityn.極性29．paralleln.并聯(lián)30．seriesn.串聯(lián)31．filamentn.燈絲32．resistorn.電阻器33．phasen.相位34．hotwire火線

Chapter1CircuitFundamentals35．neutralwire中線36．electricalpower電源4.重點(diǎn)句子翻譯[1]However,apositivechargeistheoppositeofanegativecharge.Thesechargesarecalledelectrostaticcharges.Eachchargedparticleissurroundedbyanelectrostaticfield.

然而，正電荷與負(fù)電荷的極性是相反的。這些電荷被稱為靜電荷。每一個(gè)帶電粒子被靜電場(chǎng)圍繞著。

Chapter1CircuitFundamentalsChapter1CircuitFundamentals[2]Theeffectthatelectrostaticchargeshaveoneachotherisveryimportant.Theyeitherrepel(moveaway)orattract(cometogether)eachother.Itissaidthatlikechargesrepelandunlikechargesattract.靜電荷彼此之間的影響是很重要的。它們或者排斥（遠(yuǎn)離），或者吸引（聚集）。這就是通常人們所說(shuō)的同性排斥，異性相吸。[3]Itisalsopossibletochargeothermaterialsbecausesomematerialsarechargedwhentheyarebroughtclosetoanotherchargedobject.Ifachargedrubberrodistouchedagainstanothermaterial,thesecondmaterialmaybecomecharged.

當(dāng)一些材料與另一帶電體接近時(shí)就會(huì)帶上電荷，所以它也可能使其它材料帶上電荷。如果帶電的橡膠棒與另一種材料接觸，就可能使這種材料帶上電荷。

Chapter1CircuitFundamentals[4]Electricalchargesareusedtofilterdustandsootindevicescalledelectrostaticfilters.Electrostaticprecipitatorsareusedinpowerplantstofiltertheexhaustgasthatgoesintotheair.在被稱為靜電過(guò)濾器的設(shè)備中，使用電荷來(lái)濾除灰塵和煙灰。在電廠，使用靜電濾器過(guò)濾排放到空氣中的廢氣。

Chapter1CircuitFundamentals[5]Conductorsaresaidtohavelowresistancetoelectricalcurrentflow.Conductorsusuallyhavethreeorfewerelectronsintheouterorbitoftheiratoms.導(dǎo)體對(duì)流通的電流阻力小。導(dǎo)體原子的外層軌道通常有三個(gè)或少于三個(gè)的電子。[6]Theelectronsofmaterialsthatareinsulatorsaredifficulttorelease.Insomeinsulators,theirvalenceshellsarefilledwitheightelectrons.Thevalenceshellsofothersareoverhalf-filledwithelectrons.Theatoms

Chapter1CircuitFundamentals絕緣體材料的電子難于釋放。在一些絕緣體里，它們的價(jià)電子層填充有八個(gè)電子。其它絕緣體的價(jià)電子層也填充有一半以上的電子。絕緣體材料的原子據(jù)說(shuō)是穩(wěn)定[7]Semiconductormaterialsareneitherconductorsnorinsulators.Theirclassificationalsodependsonthenumberofelectronsthattheiratomshaveintheirvalenceshells.Semiconductorshave4electronsintheirvalenceshells.

Chapter1CircuitFundamentals

半導(dǎo)體材料既不是導(dǎo)體，也不是絕緣體。它們的分類取決于原子的價(jià)電子層電子的數(shù)量。半導(dǎo)體原子的價(jià)電子層有四個(gè)電子。[8]Staticelectricityiscausedbystationarycharges.However,electricalcurrentisthemotionofelectricalchargesfromonepointtoanother.Electriccurrentisproducedwhenelectrons(-)areremovedfromtheiratoms.

Chapter1CircuitFundamentalsChapter1CircuitFundamentals

靜電是由靜止的電荷產(chǎn)生的。然而，電流是由電荷從一點(diǎn)到另一點(diǎn)的運(yùn)動(dòng)產(chǎn)生的。當(dāng)電子從它們的的原子移除時(shí)，就會(huì)產(chǎn)生電流。[9]Themovementofvalenceshellelectronsofconductorsproduceselectricalcurrent.Theouterelectronsoftheatomsofaconductorarecalledfreeelectrons.Energyreleasedbytheseelectronsastheymoveallowsworktobedone.

Chapter1CircuitFundamentals導(dǎo)體價(jià)電子層電子的運(yùn)動(dòng)產(chǎn)生電流。導(dǎo)體原子的外部電子叫做自由電子。當(dāng)這些電子運(yùn)動(dòng)時(shí)釋放出能量，從而做功。[10]Acircuitisapathorconductorforelectriccurrentflow.Electriccurrentflowsonlywhenithasacomplete,orclosed-circuit,path.Theremustbeasourceofelectricalenergytocausecurrenttoflowalongaclosedpath.Chapter1CircuitFundamentals電路是由于電流流通的路徑或?qū)w。只有當(dāng)電路是通路或閉合的路徑時(shí)才有電流流通。必須有電源來(lái)引起電流沿閉合路徑流通。[11]Anelectricalenergysourcesuchasabatteryorgeneratorproducescurrentflowthroughacircuit.Asvoltageisincreased,theamountofcurrentinthecircuitisalsoincreased.Voltageisalsocalledelectromotiveforce(EMF).Chapter1CircuitFundamentals電能源，如電池或發(fā)電機(jī)，產(chǎn)生流過(guò)電路的電流。當(dāng)電壓增加時(shí)，電路中電流的數(shù)值也增加。電壓也稱為電動(dòng)勢(shì)。[12]Atomsofsomematerialsgiveuptheirfreeelectronseasily.Thesematerialsofferlowoppositiontocurrentflow.Othermaterialsholdtheirouterelectronsandofferhighoppositiontocurrentflow.一些材料的原子容易釋放它們的自由電子。這些材料對(duì)流通電流的阻力小。而其它材料束縛它們的外層電子，對(duì)流通電流的阻力大。Chapter1CircuitFundamentals[13]Currentismeasuredbyconnectingthemeterintoacircuit,i.e.connectingthemeterinserieswiththecircuit.Currentflowsfromavoltagesourcewhensomedevicethathasresistanceisconnectedtothesource.測(cè)量電流時(shí)需把儀表接入電路中，即儀表與電路相串聯(lián)。當(dāng)某個(gè)有阻值的器件與電源相連時(shí)就會(huì)從電壓源產(chǎn)生電流。Chapter1CircuitFundamentals[14]Therearethreetypesofelectricalcircuits.Theyarecalledseriescircuits,parallelcircuits,andcombinationcircuits.Theeasiesttypeofcircuittounderstandistheseriescircuit.電路可分為三種類型。分別為串連電路，并聯(lián)電路和串并聯(lián)組合電路。串連電路是最容易理解的電路類型。Chapter1CircuitFundamentals[15]Forexample,themostimportantACvalueiscalledtheeffective,ormeasured,value.Thisvalueislessthanthepeakpositivevalue.AcommonACvoltageis220V,whichisusedinhomes.Thisisaneffectivevaluevoltage.Itspeakvalueisabout311V.例如，最重要的交流值叫做有效值或測(cè)量值。這個(gè)值比正向峰值小。通常應(yīng)用于我們家庭的交流電壓為220伏，這個(gè)電壓是有效值電壓。它的峰值電壓大約是311伏。Chapter1CircuitFundamentals[16]Thetermphasereferstotime,orthedifferencebetweenonepointandanother.Iftwosine-wavevoltagesreachtheirzeroandmaximumvaluesatthesametime,theyareinphase.術(shù)語(yǔ)“相位”指的是時(shí)間上或兩點(diǎn)之間的不同。如果兩個(gè)正弦波電壓在同一時(shí)刻到達(dá)它們的零點(diǎn)和最大值，就說(shuō)它們是同相位的。Chapter1CircuitFundamentals[17]Three-phaseACisusedtopowerlargeequipmentinindustryandcommercialbuildings.Itisnotdistributedtohomes.Therearethreepowerlinesonathree-phasesystem.Somethree-phasesystemshaveaneutralconnectionandothersdonot.在大功率工業(yè)設(shè)備和商業(yè)建筑上使用三相交流。三相交流電不配送給家庭。三相系統(tǒng)有三條動(dòng)力線。其中一些三相系統(tǒng)有中性線，而其它的沒(méi)有中性線。Chapter1CircuitFundamentals[18]Thepowerratingsofmotorsandgeneratorsisgreaterwhenthree-phaseacpowerisused.Foracertainframesize,theratingofathree-phaseacmotorisalmost50%largerthanasimilarsingle-phaseacmotor.

當(dāng)使用三相交流電源時(shí)，電動(dòng)機(jī)和發(fā)電機(jī)的功率額定值要大得多。