第1页共45页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码:第1页共45页2018年《电路分析与电子线路》综合训练题注意:2018年《电路分析与电子线路》综合训练组队共同讨论完成综合训练题目3-4题,以书面形式撰写报告,需要详细的讨论过程和仿真的结果。请同学们自学“数值分析软件(如MATLAB等)及电路仿真软件(如Multisim或Pspice等)”。提交书面报告时间:6月20日前。Project1PowerSuppliesObjective:Thisprojectwillshowsomeofthebasicprinciplesofpowersuppliesusingfullwaverectifier,Zenerdiode,andfixed-voltageregulatorcircuits.Components:BridgeRectifier(50PIV,1A),Zenerdiode(10Vat500mW),7805regulatorIntroduction:Mostofthedirectcurrent(DC)powerusedinelectronicdevicesisderivedbyconverting60Hz,115Valternatingcurrent(AC)powertodirectcurrentpower.ThisACtoDCconversionusuallyinvolvesastep-downtransformer,rectifier,filter,andaregulator.Thestep-downtransformerisusedtodecreasetheAClinevoltagefrom115VRMStoanRMSvalueneartheDCvoltageneeded.Theoutputofthestep-downtransformeristhenfedintoadioderectifiercircuitthatonlyoutputspositivehalvesoftheinputsinusoid.AfilteristhenusedtosmooththerectifieroutputtoachieveanearlyconstantDCvoltagelevel.Aregulatorcanbeaddedafterthefiltertoensureaconstantoutputvoltageinspiteofchangesinloadcurrentandinputvoltages.Twodifferenttypesofvoltageregulatorswillbeusedinthisproject.ThefirstinvolvesaZenerdiodecircuitandthesecondinvolvesavoltageregulatorcircuit.AZenerdiodecanbeusedasavoltageregulatorwhenthediodeisreversebiasedandoperatedinthebreakdownregion.Tomaintainvoltageregulation,theZenerdiodemustbeoperatedinthebreakdownregionatacurrentgreaterthanthe"knee"current(IZK).ForcurrentsgreaterthanIZK,theZenerdiodecharacteristiccurveisnearlyverticalandthevoltageacross第2页共45页第1页共45页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码:第2页共45页thediodechangesverylittle.Ofcoursethereisamaximumcurrentthediodecantolerate,sogoodregulationisprovidedwhenthediodeisreversebiasedwithcurrentsbetweenIZKandIZMAX.Zenerdiodesareavailablewithawidevarietyofbreakdownvoltages.Anothertypeofvoltageregulatorisavailablewiththe7800seriesregulators.Thisseriesoffixed-voltageregulatorsisnumbered78xx,wherexxcorrespondstothevalueoftheoutputvoltage.Outputvoltagesfrom5to24voltsareavailable.Theseregulatorsareeasytouseandworkverywell.Design:1.FindapproximationsfortheDCvoltagelevelandACpeaktopeakripplevoltageforthebridgerectifierandfiltercircuitofFigure1-1.2.FortheZenerdioderegulatorcircuitofFigure1-2assumethattheZenerdiodewillregulateat10Voveracurrentrangeof5mAto25mA.AssumingthatthecurrentflowingthroughRisalwaysbetween5mAand25mAandtheZenerdiodeisregulatingat10V,findtheminimumvaluesofRandRLrequired.Youmayassumetheforwarddiodedropforthetwodiodesis1V.第3页共45页第2页共45页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码:第3页共45页LabProcedure:1.ConstructthebridgerectifiercircuitofFigure1-1withoutthecapacitor.UsetheVariacwiththestep-downtransformerfortheinputvoltagetothebridgerectifier.WiththetransformerpluggedintotheVariac,adjusttheVariacuntilthesecondaryvoltagefromthetransformerequals12VRMS.BECAREFULnottoshortthesecondaryterminals!Observethesecondarywaveformontheoscilloscope.PuttheoscilloscopeonDCcouplingandobservetheloadvoltagewaveformVL.Rememberthatboththeinputsourceandtheloadcannotshareacommongroundterminal.第4页共45页第3页共45页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码...