泰州職業(yè)技術(shù)學院畢業(yè)論文題目直流斬波電路實驗系統(tǒng)系別電子工程系專業(yè)應用電子技術(shù)班級XX學生姓名田領學號WX308009指導教師劉老師2010年5月DCCircuitcarrierexperimentalsystemChopper-choppedDCcutthebasicideais:Iftheswitchtochangethefrequencyofaction,ortochangetheDCcurrentconnectanddisconnecttheproportionoftime,youcanchangeaddedtotheloadvoltage,currentaverage.DCchopperaccordingtothefunctionscanbedividedinto:power-controlregulationtype,type,andsoon-resistanceByDCchopperrelationshipbetweeninputandoutputvoltagecanbedividedinto:WhenUothanUin,calledstep-upchopper(BoostConverter);WhenUocanalsobelessthanUinthanUin,Calledforthereversalchoppermovementsorpressurechopper(Buck-BoostConverter)ChopperswitchonthedeviceusedbyCategory:BJTchopper,MOSFETchopper,IGBTchopper,Thyristorchopper,etc.SupportedbyDCpowerandtheenergytransferbetweenthechopperCategory:outputvoltageandcurrenttakenoirreversibleknownassinglequadrantchopper;onlyoutputcurrentorvoltageoutputirreversibleasthetwoquadrantchopper;outputcurrentandVoltageisirreversibleasfourquadrantchopperIntheunit,UHPoflargepowerprojectsandnetworkconstructionprojectinNewTown,theDCpowersupplysystemofquality,toensuresafeoperationofaveryimportantimpact.Therefore,theDCpowersupplysystem,therewillstrivetoimprovethedesign,theuseofhigh-qualityequipment,andmustbecarefulmaintenance.

Toachievethisrequirement,regardlessofengineeringdesign,equipmentmanufactureandmaintenanceofproductionworkers,theDCsystemwillneedthetechnicaltheory,performanceandproductionequipmentrequiredamorecomprehensiveunderstanding.Choppercontrolofthesignificanceis:Windingfedonlywiththeactivepowerandcurrent,phase-shiftingfromamaximumcapacityof100percentcontroloftheelectricalpowerreducedto14.8percent,theFedgovernorinthemotorofsimplified,lowercosts.Fromthefundamentalsolutiontothephase-shiftingcontrolofartificiallytriggeredreactivepowergeneratedemotionalproblems,activeinvertertriggerpulsefixed,phaselocked,andconstantpowerfactorof0.9,stronganti-interference,highreliability.Reducethecurrentharmonics.Therefore,theFedgovernorchoppertoproduceaqualitativeleap,theFedgovernoristhebestcontrolmethodsandtechniquesforimprovingthesigns.Powerelectroniccircuits,inadditiontopowerelectronicdevicessuitableparameters,drivecircuitwell-designed,theappropriateuseofover-voltage,over-current,du/dtprotection,di/diprotectionisnecessary.ChoppermaincircuitschematicsVoltagecomparatorprinciple:voltagecomparisonistheapplicationofnon-linearintegratedoperationalamplifiercircuit,commonlyusedinavarietyofelectronicequipment,thenwhatis?Voltagecomparator?BelowIwillgiveyouabout,itwillsignalananalogvoltageandafixedvoltagereference,comparedtotwointhevicinityofthesamemagnitude,theoutputvoltagewillhaveajump,high-orlow-leveloutputaccordingly.Comparisoncantransformcomposedofnon-sine-circuitandusedanaloganddigitalsignalconverter,andotherfields.ShowninFigure1forthemostsimplevoltagecomparator,URforreference,theincreaseinoperationalamplifierwiththeinputphase,theinputvoltageoftheRP-uiincreaseininput.

Figure12voltagecomparisonprincipleofPrinciple

(a)circuit(b)transmissioncharacteristicswhenui<UR,Yun-outputHIGHRegulatorsDzreverseregulatorofwork.PotentialoutputwasatitsclampingvoltageregulatortothestabilityoftheUZ,thatis,uO=UZ(2-1)Whenui>UR,Yun-lowoutput,DZisthewizard-,equivalenttotheoutputvoltageregulatoroftheforwardvoltagedropUD,thatis,uo=-UD(2-2)Therefore,toURforthesector,whentheinputvoltageuichanges,theoutputreflectsthetwostates,highpotentialandlowpotential.Thattheoutputvoltagewiththeinputvoltageoftherelationshipbetweenthecurve,knownasthetransmissioncharacteristics.Figure12(b)as(a)planscomparedwiththetransmissioncharacteristics.Thevoltageusedforcomparisontherehavebeenzero-voltagecomparator,ahysteresisofzerocomparison,hystereticvoltagecomparator,thewindow(evenlimited)voltagecomparator.LM339usedtoadifferentvoltagecomparatorVoltagefollower,asthenamesuggests,isthattheoutputvoltagewiththeinputvoltageisthesame,thatistosay,voltagefollow-voltagegainislessthanconstantandcloseto1.Thefollow-voltagenotablefeatureisthattheinputimpedancehigh,andlowoutputimpedance,ingeneral,theinputimpedancetoachieveJizhaoOhmisveryeasytodo.Outputimpedancelow,usuallytoafewohms,orevenlower.Inthecircuit,voltagefollowertobufferthegenerallevelandisolationlevel.Thisisbecausethevoltageoutputimpedanceamplifiersaregenerallyhigh,usuallyinthethousandstoseveralEuropeanEurope,iftheafter-classinputimpedanceisrelativelysmall,itwillsignalaconsiderablepartofthefirst-classlossinoutputresistance.Atthistime,itisnecessarytofollowthevoltagefromabuffer.Theconnectinglinkbetweentheprecedingplayarole.ApplicationofvoltagefollowerAnotheradvantageisthatincreasedinputimpedance,sothatinputcapacitancecangreatlyreducethecapacityfortheapplicationofhigh-qualitycapacitorprovideaguaranteethatpremise.Thevoltagewithanotherrolethatisisolated,HI-FIcircuit,thenegativefeedbackonthedisputehasbeenalongtime,infact,ifnottheroleofnegativefeedback,Ibelievethemajorityoftheamplifierisnotaverygoodjob.However,duetotheintroductionofalargenegativefeedbackloopcircuit,thespeakerwillbeadoptedbytheanti-EMFfeedbackcircuit,withtheinputsignalsuperimposed.Afuzzysoundquality,claritydecreased,so,someoftheamplifierattheendofclasswithouttheuseofanegativefeedbackloopofthecircuit,tryingtodisconnectthenegativefeedbacklooptoeliminatethenegativefeedbackloopofthedefects.However,becausetheamplifierlevelattheendofthecurrentworkofgreatchanges,itsdifficulttoensurethatdistortion.Undervoltagelatchalsoknownaslow-voltagelatches,referringtothepowersupplyforsomereason(suchaspowerfromthebattery-powered,thebatteryvoltageistoolow)sothattheoutputvoltagedowntoacertainlimit(forexample,5VpowersupplydropLimitto4.5V),under-voltagecircuitcanlatchautomaticallycutoffpowersupplycutoffandmaintainthestatus(latch),suchassupplyvoltageaboveacertainlimitrosetoavalue(asintheexampleabovethe4.72V),Circuitrestorepowersupply.Thisisnotguaranteedbecauseoflowvoltagecausedbycircuitisnotworkingproperlyorcircuitperformanceultra-poormeasuresofprotection.Accordingtoastep-upDC-DCPwMchipdesignrequirements,theneedtoinputvoltageVDDandunder-voltagethresholdtocomparelatchestoensurethatVDDhighenoughtomeettherequirementsofchipsandreliablework.WhenVDDthresholdsettoriseto2.5V,whenVDDfallsetthethresholdfor2.35V,this150mVundervoltagethresholdhysteresislatchontoavoidtheintervalsupplyvoltagefluctuationsleadtofrequentre-chipActivatedtoensurethereliabilityofelectronicequipment,fortheimproveddesignoftheUVLOcircuit.AsshowninFigure2,improvedUVLOcircuituseofthebandgapvoltagereferenceoftheprinciplestructure.ResistanceR1,R2andtransistorsQ1,Q2constitutesatwobandgapreferencevoltagesourceofthestructure[2],Q2,Q1emitteroftheratioofQ2/Q1=8,resistorsR3,R4andaMOSofM5M6Thebandgapreferenceofthecurrentsourceactiveload.R8andcapacitanceM4tostabilizeUVLOvoltage.Externalshutdownsignaltotheoutputlevelandsoft-startcircuitryallplayarole.WhenShutdown(10-pin),whenthesignalisHIGH,PWMSuoregisterswillimmediatelymovetobantheexportSG3525,atthesametime,soft-startcapacitorwillbegintodischarge.Ifthehigh-sustained,soft-startcapacitorwillfullydischargeuntiltheshutdownsignaltheend,onlytore-enterthesoft-starttheprocess.Note,Shutdownpincannotbeleftvacant,throughthegroundingresistancereliableground,topreventexternalinterferencesignalcouplingSG3525affectedthenormalwork.Undervoltagelockoutroleinthesameoutputlevelandsoft-startcircuitry.Iftheinputvoltageistoolow,theoutputintheSG3525wasshutdownatthesametime,soft-startcapacitorwillbegintodischargFromtheabovechopperprocesswecanseethattheimpulsecontrolVT2momenttoadjusttheoutputvoltagepulse,whichcanreachDCoutputvoltageregulationpurposes.VT1,VT2thetriggerpulseintervalsdeterminedbythetriggercircuit.Choppertriggercircuitandtheprincipleofacontentcanbefound.Experimentalwiringasshownbelow,withresistanceRD42three-phaseadjustableresistance,withoneofthe900Ωresistance;excitationpowerandDCvoltage,Ammetersareincontrolofon-screenchoppertriggercircuitdebugging

DJK05panelonregulatingthepotentialforRP1,RP2,RP1regulationsawtoothupperandlower-levelposition,andRP2toadjustthefrequencysawtooth.First-conditioningRP2,willadjustthefrequencyto200Hz~300Hzbetween,andthenensurethattriangleyetreallycircumstances,adjustingforthe1.30-RP1provideabiasvoltage(closetosupplyvoltage),themaincircuitchoppertotheworkofacertainStartDCvoltageforthemaintenanceofcertainSCRcurrent,reliablesystemtoensurethattheworkwillbeontheDJK06givenaccesstoobservethetriggerpointofthesecondwavecircuit,givenincreased,from0.3transferredtothedutycycle0.9.(2)DCinputvoltageofthecircuitfromACuibytherectifier,suchasexperimentalasshowninFigure2a.Figure2bexperimentforthebuckchoppermaincircuitFigure4buckchoppermaincircuitandcontrolcircuitDCpowersupplyb)buckchoppermaincircuitc)controlanddrivecircuitchoppercircuitvoltageDCinputuilow-voltagesingle-phaseACpowerfromthesingle-phasebridgerectifierdiodesandcapacitorsfilteredbyICPSG3525soft-start-access(8-pin),usuallybyone-fifthofsoft-startcapacitor.Powerprocess,duetovoltagecapacitorendsofthemutationcannot,andthesoft-startcapacitorconnectedtotheaccess-PWMcomparatorreverseinalow-levelinput,PWMcomparatoroutputHIGH.Atthispoint,PWMSuooftheoutputisalsohigh,thehigh-doorthroughtwooraddedtotheoutputtransistors,sothatitcannot-on.Onlysoft-startcapacitorchargetothevoltageonits8-pininthehigh-time,SG3525onlystartedwork.Aspractice,thereferencevoltageisusuallyreceivedinerroramplifierwiththesameinput,andvoltageoutputvoltageofsamplingerrorisplusintheRP-amplifierinputon.Whentheoutputvoltageduetotheincreaseofinputvoltageorchangesintheloadincreased,theerroramplifieroutputwillbereduced,thiswillleadtocomparePWMoutputforthetimebeinglonger,PWMoutputofhigh-SuotimeAlsolonger,sotheoutputtransistoron-timewilleventuallyshortened,sothattheoutputvoltagedowntoratingsandachieveasteadystate.Andviceversa.Voltagecomparatorprinciple:voltagecomparisonistheapplicationofnon-linearintegratedoperationalamplifiercircuit,commonlyusedinavarietyofelectronicequipment,thenwhatis?Voltagecomparator?BelowIwillgiveyouabout,itwillsignalananalogvoltageandafixedvoltagereference,comparedtotwointhevicinityofthesamemagnitude,theoutputvoltagewillhaveajump,high-orlow-leveloutputaccordingly.Comparisoncantransformcomposedofnon-sine-circuitandusedanaloganddigitalsignalconverter,andotherfields.ShowninFigure1forthemostsimplevoltagecomparator,URforreference,theincreaseinoperationalamplifierwiththeinputphase,theinputvoltageoftheRP-uiincreaseininput.

Figure12voltagecomparisonprincipleofPrinciple

(a)circuit(b)transmissioncharacteristicswhenui<UR,Yun-outputHIGHRegulatorsDzreverseregulatorofwork.PotentialoutputwasatitsclampingvoltageregulatortothestabilityoftheUZ,thatis,uO=UZ(2-1)Whenui>UR,Yun-lowoutput,DZisthewizard-,equivalenttotheoutputvoltageregulatoroftheforwardvoltagedropUD,thatis,uo=-UD(2-2)Therefore,toURforthesector,whentheinputvoltageuichanges,theoutputreflectsthetwostates,highpotentialandlowpotential.Thattheoutputvoltagewiththeinputvoltageoftherelationshipbetweenthecurve,knownasthetransmissioncharacteristics.Figure12(b)as(a)planscomparedwiththetransmissioncharacteristics.Thevoltageusedforcomparisontherehavebeenzero-voltagecomparator,ahysteresisofzerocomparison,hystereticvoltagecomparator,thewindow(evenlimited)voltagecomparator.LM339usedtoadifferentvoltagecomparatorVoltagefollower,asthenamesuggests,isthattheoutputvoltagewiththeinputvoltageisthesame,thatistosay,voltagefollow-voltagegainislessthanconstantandcloseto1.Thefollow-voltagenotablefeatureisthattheinputimpedancehigh,andlowoutputimpedance,ingeneral,theinputimpedancetoachieveJizhaoOhmisveryeasytodo.Outputimpedancelow,usuallytoafewohms,orevenlower.Inthecircuit,voltagefollowertobufferthegenerallevelandisolationlevel.Thisisbecausethevoltageoutputimpedanceamplifiersaregenerallyhigh,usuallyinthethousandstoseveralEuropeanEurope,iftheafter-classinputimpedanceisrelativelysmall,itwillsignalaconsiderablepartofthefirst-classlossinoutputresistance.Atthistime,itisnecessarytofollowthevoltagefromabuffer.Theconnectinglinkbetweentheprecedingplayarole.ApplicationofvoltagefollowerAnotheradvantageisthatincreasedinputimpedance,sothatinputcapacitancecangreatlyreducethecapacityfortheapplicationofhigh-qualitycapacitorprovideaguaranteethatpremise.Thevoltagewithanotherrolethatisisolated,HI-FIcircuit,thenegativefeedbackonthedisputehasbeenalongtime,infact,ifnottheroleofnegativefeedback,Ibelievethemajorityoftheamplifierisnotaverygoodjob.However,duetotheintroductionofalargenegativefeedbackloopcircuit,thespeakerwillbeadoptedbytheanti-EMFfeedbackcircuit,withtheinputsignalsuperimposed.Afuzzysoundquality,claritydecreased,so,someoftheamplifierattheendofclasswithouttheuseofanegativefeedbackloopofthecircuit,tryingtodisconnectthenegativefeedbacklooptoeliminatethenegativefeedbackloopofthedefects.However,becausetheamplifierlevelattheendofthecurrentworkofgreatchanges,itsdifficulttoensurethatdistortion.Undervoltagelatchalsoknownaslow-voltagelatches,referringtothepowersupplyforsomereason(suchaspowerfromthebattery-powered,thebatteryvoltageistoolow)sothattheoutputvoltagedowntoacertainlimit(forexample,5VpowersupplydropLimitto4.5V),under-voltagecircuitcanlatchautomaticallycutoffpowersupplycutoffandmaintainthestatus(latch),suchassupplyvoltageaboveacertainlimitrosetoavalue(asintheexampleabovethe4.72V),Circuitrestorepowersupply.Thisisnotguaranteedbecauseoflowvoltagecausedbycircuitisnotworkingproperlyorcircuitperformanceultra-poormeasuresofprotection.Accordingtoastep-upDC-DCPwMchipdesignrequirements,theneedtoinputvoltageVDDandunder-voltagethresholdtocomparelatchestoensurethatVDDhighenoughtomeettherequirementsofchipsandreliablework.WhenVDDthresholdsettoriseto2.5V,whenVDDfallsetthethresholdfor2.35V,this150mVundervoltagethresholdhysteresislatchontoavoidtheintervalsupplyvoltagefluctuationsleadtofrequentre-chipActivatedtoensurethereliabilityofelectronicequipment,fortheimproveddesignoftheUVLOcircuit.AsshowninFigure2,improvedUVLOcircuituseofthebandgapvoltagereferenceoftheprinciplestructure.ResistanceR1,R2andtransistorsQ1,Q2constitutesatwobandgapreferencevoltagesourceofthestructure[2],Q2,Q1emitteroftheratioofQ2/Q1=8,resistorsR3,R4andaMOSofM5M6Thebandgapreferenceofthecurrentsourceactiveload.R8andcapacitanceM4tostabilizeUVLOvoltage.Externalshutdownsignaltotheoutputlevelandsoft-startcircuitryallplayarole.WhenShutdown(10-pin),whenthesignalisHIGH,PWMSuoregisterswillimmediatelymovetobantheexportSG3525,atthesametime,soft-startcapacitorwillbegintodischarge.Ifthehigh-sustained,soft-startcapacitorwillfullydischargeuntiltheshutdownsignaltheend,onlytore-enterthesoft-starttheprocess.Note,Shutdownpincannotbeleftvacant,throughthegroundingresistancereliableground,topreventexternalinterferencesignalcouplingSG3525affectedthenormalwork.Undervoltagelockoutroleinthesameoutputlevelandsoft-startcircuitry.Iftheinputvoltageistoolow,theoutputintheSG3525wasshutdownatthesametime,soft-startcapacitorwillbegintodischarge.Figure5SG3525externalpinmapFigure6buckcircuitschematicsFigure7SG3525internaldiagramSoft-startisthestartofabuck,usethepowerofelectronictechnologythatSCRtechnology,canbeactivatedinthemotorvoltagePromiseZhongshismoothprocessfromtheinitialvalueofuptothetotalpressure.Thatis,theso-calledsoft-startthemotorofasoftstart,thestartofthecurrenteffectivecontrol,thegeneralapproachnowiselectronic,throughtheBTAorhigh-powerelectronicdevices,andnopowertochangethefrequencyofelectricityandElectricityisthevoltagedrop,thecurrentcut.Soft-startthroughthemaincircuitintheelectricaltransformerpiecesorseriesconnectionfrequencydividerpiecessothatthemotorstartedintheprocess,theterminalvoltagefromasetofautomatic-uptofullpressure,sothatasmoothmotorspeedincreasedtoafull-speedAmotorlaunchmode.Soft-startadvantages:1.Inthewholeprocessstartedinthemotorsteadyacceleration,nomechanicalimpact.2.Asfaraspossibletoreducethestartingcurrent,sothatnocurrentimpactofswitchingReferencetothemoredistortionInouranalysis,isthethreeofthethresholdvoltageaszero,butinreality,thethresholdvoltagecannotbezero,andtherelationshipbetweenvoltageandcurrentisnotlinear,lowinputvoltage,outputvoltage,thereisadeath,Thissectionistheoutputvoltagewiththeinputvoltagethereisnolinearrelationship,adistortion.Thisdistortionintheadoptionofzerovalue,soitiscalledpaymoredistortion.Voltagecomparatorprinciple:voltagecomparisonistheapplicationofnon-linearintegratedoperationalamplifiercircuit,commonlyusedinavarietyofelectronicequipment,thenwhatis?Voltagecomparator?BelowIwillgiveyouabout,itwillsignalananalogvoltageandafixedvoltagereference,comparedtotwointhevicinityofthesamemagnitude,theoutputvoltagewillhaveajump,high-orlow-leveloutputaccordingly.Comparisoncantransformcomposedofnon-sine-circuitandusedanaloganddigitalsignalconverter,andotherfields.ShowninFigure1forthemostsimplevoltagecomparator,URforreference,theincreaseinoperationalamplifierwiththeinputphase,theinputvoltageoftheRP-uiincreaseininput.

Figure12voltagecomparisonprincipleofPrinciple

(a)circuit(b)transmissioncharacteristicswhenui<UR,Yun-outputHIGHRegulatorsDzreverseregulatorofwork.PotentialoutputwasatitsclampingvoltageregulatortothestabilityoftheUZ,thatis,uO=UZ(2-1)Whenui>UR,Yun-lowoutput,DZisthewizard-,equivalenttotheoutputvoltageregulatoroftheforwardvoltagedropUD,thatis,uo=-UD(2-2)Therefore,toURforthesector,whentheinputvoltageuichanges,theoutputreflectsthetwostates,highpotentialandlowpotential.Thattheoutputvoltagewiththeinputvoltageoftherelationshipbetweenthecurve,knownasthetransmissioncharacteristics.Figure12(b)as(a)planscomparedwiththetransmissioncharacteristics.Thevoltageusedforcomparisontherehavebeenzero-voltagecomparator,ahysteresisofzerocomparison,hystereticvoltagecomparator,thewindow(evenlimited)voltagecomparator.LM339usedtoadifferentvoltagecomparatorVoltagefollower,asthenamesuggests,isthattheoutputvoltagewiththeinputvoltageisthesame,thatistosay,voltagefollow-voltagegainislessthanconstantandcloseto1.Thefollow-voltagenotablefeatureisthattheinputimpedancehigh,andlowoutputimpedance,ingeneral,theinputimpedancetoachieveJizhaoOhmisveryeasytodo.Outputimpedancelow,usuallytoafewohms,orevenlower.Inthecircuit,voltagefollowertobufferthegenerallevelandisolationlevel.Thisisbecausethevoltageoutputimpedanceamplifiersaregenerallyhigh,usuallyinthethousandstoseveralEuropeanEurope,iftheafter-classinputimpedanceisrelativelysmall,itwillsignalaconsiderablepartofthefirst-classlossinoutputresistance.Atthistime,itisnecessarytofollowthevoltagefromabuffer.Theconnectinglinkbetweentheprecedingplayarole.ApplicationofvoltagefollowerAnotheradvantageisthatincreasedinputimpedance,sothatinputcapacitancecangreatlyreducethecapacityfortheapplicationofhigh-qualitycapacitorprovideaguaranteethatpremise.Thevoltagewithanotherrolethatisisolated,HI-FIcircuit,thenegativefeedbackonthedisputehasbeenalongtime,infact,ifnottheroleofnegativefeedback,Ibelievethemajorityoftheamplifierisnotaverygoodjob.However,duetotheintroductionofalargenegativefeedbackloopcircuit,thespeakerwillbeadoptedbytheanti-EMFfeedbackcircuit,withtheinputsignalsuperimposed.Afuzzysoundquality,claritydecreased,so,someoftheamplifierattheendofclasswithouttheuseofanegativefeedbackloopofthecircuit,tryingtodisconnectthenegativefeedbacklooptoeliminatethenegativefeedbackloopofthedefects.However,becausetheamplifierlevelattheendofthecurrentworkofgreatchanges,itsdifficulttoensurethatdistortion.Undervoltagelatchalsoknownaslow-voltagelatches,referringtothepowersupplyforsomereason(suchaspowerfromthebattery-powered,thebatteryvoltageistoolow)sothattheoutputvoltagedowntoacertainlimit(forexample,5VpowersupplydropLimitto4.5V),under-voltagecircuitcanlatchautomaticallycutoffpowersupplycutoffandmaintainthestatus(latch),suchassupplyvoltageaboveacertainlimitrosetoavalue(asintheexampleabovethe4.72V),Circuitrestorepowersupply.Thisisnotguaranteedbecauseoflowvoltagecausedbycircuitisnotworkingproperlyorcircuitperformanceultra-poormeasuresofprotection.Accordingtoastep-upDC-DCPwMchipdesignrequirements,theneedtoinputvoltageVDDandunder-voltagethresholdtocomparelatchestoensurethatVDDhighenoughtomeettherequirementsofchipsandreliablework.WhenVDDthresholdsettoriseto2.5V,whenVDDfallsetthethresholdfor2.35V,this150mVundervoltagethresholdhysteresislatchontoavoidtheintervalsupplyvoltagefluctuationsleadtofrequentre-chipActivatedtoensurethereliabilityofelectronicequipment,fortheimproveddesignoftheUVLOcircuit.AsshowninFigure2,improvedUVLOcircuituseofthebandgapvoltagereferenceoftheprinciplestructure.ResistanceR1,R2andtransistorsQ1,Q2constitutesatwobandgapreferencevoltagesourceofthestructure[2],Q2,Q1emitteroftheratioofQ2/Q1=8,resistorsR3,R4andaMOSofM5M6Thebandgapreferenceofthecurrentsourceactiveload.R8andcapacitanceM4tostabilizeUVLOvoltage.Externalshutdownsignaltotheoutputlevelandsoft-startcircuitryallplayarole.WhenShutdown(10-pin),whenthesignalisHIGH,PWMSuoregisterswillimmediatelymovetobantheexportSG3525,atthesametime,soft-startcapacitorwillbegintodischarge.Ifthehigh-sustained,soft-startcapacitorwillfullydischargeuntiltheshutdownsignaltheend,onlytore-enterthesoft-starttheprocess.Note,Shutdownpincannotbeleftvacant,throughthegroundingresistancereliableground,topreventexternalinterferencesignalcouplingSG3525affectedthenormalwork.Undervoltagelockoutroleinthesameoutputlevelandsoft-startcircuitry.Iftheinputvoltageistoolow,theoutputintheSG3525wasshutdownatthesametime,soft-startcapacitorwillbegintodischargWepaymoretoovercomethedistortionmeasuresare:toavoiddead-voltageareas,sothateachtransistoron-a-state,onceaccessiontotheinputsignaltoimmediatelyenterthelinearworkarea.Complementarycomponentsofthepoweramplifiercircuitsymmetryoftheoutputcurrentaregreat,andthegeneralpowerofthemagnificationfactordoesnot,tothisendwehavetoenlargecurrent,generallythroughthecompositepipetosolvetheproblem.PowerofchoicefortheprincipleofselectionprinciplesReferences[1]JohnNewbury，WilliamMiller.MultiprotocolRoutingforAutomaticRemoteMeterReadingUsingPowerLineCarrierSystems［J］.IEEETRANSACTIONSONPOWERDELIVERY,2001［２］ManfredZimmermann，KlausDostert.AnalysisandModelingofImpulsiveNoisinBroad-BandPowerlineCommunications［J］.IEEETRANSACTIONSONELECTROMAGETICCOMPATIBLITY,2002［３］CharlesJKim，MohamedFChouikha.AttenuationCharacteristicsofHighRateHome-NetworkingPLCSignals［J］.IEEETRANSACTIONSONPOWERDELIVERY,2002［４］TianYewLim，Tat-WaiChan.ExperimentingRemoteKilowatthourMeterReadingThroughLow-VoltagePowerLinesatDenseHousingEstates［J］.IEEETRANSACTIONSONPOWERDELIVERY,2002［５］ManfredZimmermann，KlausDostert.AMultipathModelforthePowerlineChannel［J］.IEEETRANSACTIONSONCOMMUNICATIONS,2002，５０［６］JMichaelSilva，BruceWhitney.EvaluationofthePotentialforPLCtoInterfereWithUseoftheNationwideDifferentialGPSNetwork［J］.IEEETRANSACTIONSONPOWERDELIVERY,2002直流斬波電路實驗系統(tǒng)用斬波器斬切直流的基本思想是：如果改變開關(guān)的動作頻率，或改變直流電流接通和斷開的時間比例，就可以改變加到負載上的電壓、電流平均值。依直流斬波器的功能可以分為：功率控制型、調(diào)壓型、調(diào)阻型等等按直流斬波器輸入輸出電壓間關(guān)系可以分為：當Uo大于Uin時，稱其為升壓斬波器(BoostConverter)；當Uo既可以小于Uin也可以大于大于Uin時，稱其為反轉(zhuǎn)斬波器或升降壓斬波器（Buck-BoostConverter）按斬波開關(guān)所采用的器件分類：BJT斬波器、MOSFET斬波器、IGBT斬波器、Thyristor斬波器等等按直流電源與負載間的能量傳遞關(guān)系對斬波器分類：輸出電壓和電流皆不可逆的稱為單象限斬