Tahmid's Blog_ Using the SG3525 PWM Controller - Explanation and Example_ Circuit Diagram _ Schematic of Push-Pull Converter

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Monday,January7,2013

UsingtheSG3525PWMControllerExplanationandExample:CircuitDiagram/SchematicofPushPullConverter

PWMisusedinallsortsofpowercontrolandconvertercircuits.Somecommonexamplesincludemotorcontrol,DCDCconverters,DCACinvertersandlampdimmers.TherearenumerousPWMcontrollersavailablethatmaketheuseandapplicationofPWMquiteeasy.OneofthemostpopularofsuchcontrollersistheversatileandubiquitousSG3525producedbymultiplemanufacturersSTMicroelectronics,FairchildSemiconductors,OnSemiconductors,tonameafew.

SG3525isusedextensivelyinDCDCconverters,DCACinverters,homeUPSsystems,solarinverters,powersupplies,batterychargersandnumerousotherapplications.Withproperunderstanding,youcansoonstartusingSG3525yourselfinsuchapplicationsoranyotherapplicationreallythatdemandsPWMcontrol.

Beforegoingontothedescriptionandapplication,letsfirsttakealookattheblockdiagramandthepinlayout.

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Pins1(InvertingInput)and2(NonInvertingInput)aretheinputstotheonboarderroramplifier.Ifyouarewonderingwhatthatis,youcanthinkofitasacomparatorthatcontrolstheincreaseordecreaseofthedutycycleforthefeedbackthatyouassociatewithPulseWidthModulation(PWM).

ThisfunctionseithertoincreaseordecreasethedutycycledependingonthevoltagelevelsontheInvertingandNonInvertingInputspins1and2respectively.

WhenvoltageontheInvertingInput(pin1)isgreaterthanvoltageontheNonInvertingInput(pin2),dutycycleisdecreased.

WhenvoltageontheNonInvertingInput(pin2)isgreaterthanvoltageontheInvertingInput(pin1),dutycycleisincreased.

ThefrequencyofPWMisdependentonthetimingcapacitanceandthetimingresistance.Thetimingcapacitor(CT)isconnectedbetweenpin5andground.Thetimingresistor(RT)isconnectedbetweenpin6andground.Theresistancebetweenpins5and7(RD)determinesthedeadtime(andalsoslightlyaffectsthefrequency).

ThefrequencyisrelatedtoRT,CTandRDbytherelationship:

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WithRTandRDinandCTinF,fisinHz.

TypicalvaluesofRDareintherange10to47.Therangeofvaluesusable(asspecifiedbythemanufacturersofSG3525)is0to500.

RTmustbewithintherange2kto150k.CTmustbewithintherange1nF(code102)to0.2F(code224).Theoscillatorfrequencymustbewithintherange100Hzto400kHz.Thereisaflipflopbeforethedriverstage,duetowhichyouroutputsignalswillhavefrequencieshalfthatoftheoscillatorfrequencythatiscalculatedusingtheabovementionedformula.So,ifyouarelookingtousethisfora50Hzinverter,yourequiredrivesignalsof50Hz.So,theoscillatorfrequencymustbe100Hz.

Acapacitanceconnectedbetweenpin8andgroundprovidesthesoftstartfunctionality.Thelargerthecapacitance,thelargerthesoftstarttime.Thismeansthatthetimetakentogofrom0%dutycycletothedesireddutycycleormaximumdutycycleislarger.So,thedutycycleincreasesmoreslowlyinitially.Keepinmindthatthisonlyaffectsinitialrateofincreaseofdutycycle,ie,therateofincreaseofdutycycleaftertheSG3525startsup.

Typicalvaluesofthesoftstartcapacitanceliewithintherange1Fto22Fdependingonthedesiredsoftstarttime.

Pin16istheoutputfromthevoltagereferencesection.SG3525containsaninternalvoltagereferencemoduleratedat+5.1Vthatistrimmedtoprovidea1%accuracy.Thisreferenceisoftenusedtoprovideareferencevoltagetotheerroramplifierforsettingthefeedbackreferencevoltage.Itcanbedirectlyconnectedtooneoftheinputsoravoltagedividercanbeusedtofurtherscaledownthevoltage.

Pin15isVCCthesupplyvoltagetotheSG3525thatmakesitrun.VCCmustliewithintherange8Vto35V.SG3525hasanundervoltagelockoutcircuitthatpreventsoperationwhenVCCisbelow8V,thuspreventingerroneousoperationormalfunction.

Pin13isVCthesupplyvoltagetotheSG3525driverstage.ItisconnectedtothecollectorsoftheNPNtransistorsintheoutputtotempolestage.HencethenameVC.VCmustliewithintherange4.5Vto35V.TheoutputdrivevoltagewillbeonetransistorvoltagedropbelowVC.SowhendrivingPowerMOSFETs,VCshouldbewithintherange9Vto18V(asmostPowerMOSFETsrequireminimum8VtobefullyonandhaveamaximumVGSbreakdownvoltageof20V).FordrivinglogiclevelMOSFETs,lowerVCmaybeused.CaremustbetakentoensurethatthemaximumVGSbreakdownvoltageoftheMOSFETisnotcrossed.SimilarlywhentheSG3525outputsarefedtoanotherdriverorIGBT,VCmustbeselectedaccordingly,keepinginmindtherequiredvoltageforthedevicebeingfedordriven.ItiscommonpracticetotieVCtoVCCwhenVCCisbelow20V.

Pin12istheGroundconnectionandshouldbeconnectedtothecircuitground.Itmustshareacommongroundwiththedeviceitdrives.

Pins11and14aretheoutputsfromwhichthedrivesignalsaretobetaken.TheyaretheoutputsoftheSG3525internaldriverstageandcanbeusedtodirectlydriveMOSFETsandIGBTs.Theyhaveacontinuouscurrentratingof100mAandapeakratingof500mA.Whengreatercurrentorbetterdriveisrequired,afurtherdriverstageusingdiscretetransistorsoradedicateddriverstageshouldbeused.Similarlyadriverstageshouldbeused

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Tahmid

IamSyedTahmidMahbub,fromDhaka,Bangladesh,bornonAugust1,1994.

AboutMe

whendrivingthedevicecausingexcessivepowerdissipationandheatingofSG3525.WhendrivingMOSFETsinabridgeconfiguration,highlowsidedriversorgatedrivetransformersmustbeusedastheSG3525isdesignedonlyforlowsidedrive.

Pin10isshutdown.Whenthispinislow,PWMisenabled.Whenthispinishigh,thePWMlatchisimmediatelyset.Thisprovidesthefastestturnoffsignaltotheoutputs.Atthesametimethesoftstartcapacitorisdischargedwitha150Acurrentsource.AnalternativemethodofshuttingdowntheSG3525istopulleitherpin8orpin9low.However,thisisnotasquickasusingtheshutdownpin.So,whenquickshutdownisrequired,ahighsignalmustbeappliedtopin10.Thispinshouldnotbeleftfloatingasitcouldpickupnoiseandcauseproblems.So,thispinisusuallyheldlowwithapulldownresistor.

Pin9iscompensation.Itmaybeusedinconjunctionwithpin1toprovidefeedbackcompensation.

Nowthatweveseenthefunctionofeachpin,letsdesignacircuitwiththeSG3525andseehowitisputtousepractically.

Letsmakeacircuitrunningat50kHz,drivingMOSFETs(inapushpullconfiguration)thatdriveaferritecorewhichthenstepsupthehighfrequencyACandthenisrectifiedandfilteredtogivea290VregulatedoutputDCthatcanbeusedtorunoneormoreCFLs.

Fortheturnscalculation,checkoutmyarticle"FerriteTransformerTurnsCalculationforHighFrequency/SMPSInverter":http://tahmidmc.blogspot.com/2012/12/ferritetransformerturnscalculation.html

Soheresthecircuit(clickonthecircuittoenlargetheimage):

ElectronicsismypassionandfromclassV,Ihavebeenlearningelectronics.IlearntandworkedmostlyonSMPS,powerelectronics,microcontrollersandintegrationofmicrocontrollerswithSMPSandpowerelectronics.I'veusedPICandAVRmicrocontrollersPIC10F,12F,16F,18F,24F,dsPIC30F,33F,PIC32,ATmegaandATtiny,integratingthemwithvariousSMPSandpowerelectronicscircuits.IamnowastudentofCornellUniversity(Classof2017)inIthaca,NewYork,USA.IwillmajorinElectricalandComputerEngineering(ECE)andhavebeenattendingclassesfromFall'13.Iamamemberoftheforumwww.edaboard.com,whereIaman"AdvancedMemberLevel5"(thehighestlevelattainable)andalsotheforumallaboutcircuits.com,whereIama"SeniorMember".Ipostontheforumsandblogsintheforumstohelpsolveelectronicsrelatedproblemsofengineersandengineeringstudentsfromallovertheworld.IalsoenjoyprogrammingusingVisualBasic(6,.NET,2005,2008,2010).Ilovewatchingandplayingcricketandfootball(soccer),andlisteningtomusic.Viewmycompleteprofile

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LetsanalyzeitandseewhatIvedone.

Youcanfirstlyseethatthesupplyvoltagehasbeenprovidedandgroundhasbeenconnected.AlsonoticethatVChasbeenconnectedtoVCC.Iveaddedabulkandadecouplingcapacitoracrossthesupplypins.Thedecouplingcapacitor(0.1F)shouldbeplacedasclosetotheSG3525aspossible.Youshouldalwaysusethisinallyourdesigns.Donotomitthebulkcapacitoreither,althoughyoumayuseasmallervalue.

Letsseepins5,6and7.IveaddedasmallresistanceRD(betweenpins5and7)thatprovidesalittledeadtime.IveconnectedRTbetweenpin6andgroundandCTbetweenpin5andground.RD=22,CT=1nF(Code:102)andRT=15k.Thisgivesanoscillatorfrequencyof:

Astheoscillatorfrequencyis94.6kHz,theswitchingfrequencyis0.5*94.6kHz=47.3kHzandthisiscloseenoughtoourtargetfrequencyof50kHz.Nowifyouhadneeded50kHzaccurate,thenthebestwaywouldhavebeentouseapot(variableresistor)inserieswithRTandadjustthepot,ortouseapot(variableresistor)asRT,althoughIpreferthefirstasitallowsforfinetuningthefrequency.

Letslookatpin8now.Iveconnecteda1Fcapacitorfrompin8togroundandthisprovidesasmallsoftstart.Iveavoidedusingtoolargeasoftstartastheslowdutycycleincrease(andthustheslowincreaseinvoltage)causesproblemswhenusingCFLsattheoutput.

Letslookatpin10now.InitiallyitspulleduptoVREFwithapullupresistor.So,PWMisdisabledanddoesnotrun.However,whentheswitchison,pin10isnowatgroundandsoPWMisenabled.So,wevemadeuseoftheSG3525shutdownoption(viapin10).Thustheswitchactslikeanon/offswitch.

Pin2isconnectedtoVREFandisthusatapotentialof+5.1V(1%).Theoutputoftheconverterisconnectedtopin1throughavoltagedividerwithresistances56kand1k.Voltageratiois57:1.Atfeedbackequilibrium,voltageatpin1is5.1Vaswellasthisisthetargetoftheerroramplifiertoadjustthedutycycletoadjustthevoltageatpin1sothatitisequaltothatofpin2.So,whenvoltageatpin1is5.1V,voltageatoutputis5.1V*57=290.7Vandthisiscloseenoughtoour290Vtarget.Ifgreateraccuracyisrequired,oneoftheresistorscanbeeitherreplacedwithapotorinserieswithapotandthepotadjustedtogiverequiredreading.

Theparallelcombinationoftheresistorandcapacitorbetweenpins1and9providesfeedbackcompensation.Iwontgointodetailintofeedbackcompensationasitisavasttopiconitsown.

Pins11and14drivetheMOSFETs.Thereareresistorsinserieswiththegatetolimitgatecurrent.TheresistorsfromgatetosourceensurethatMOSFETsdontgetaccidentallyturnedon.

Sothatsaboutit.Youcanseethatthisisquiteaneasycircuittodesign.Ifyouveunderstoodallofthis,youcannowdesigncircuitswithSG3525yourself.Trytomakeafew,egfor50Hzoutputandwithisolatedfeedback.Ifyoucantdontworry,Illputupanotherarticlewithafewmorecircuits

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PostedbyTahmidat4:59AM

Labels:inverter,pushpull,SG3525,SG3525,SG3525circuit

usingSG3525sothatyoubecomecompletelyclearwithit(ifyouhaventalready).

Referencedocuments:

SG3525datasheet:www.onsemi.com/pub/Collateral/SG3525AD.PDFFerriteTransformerTurnsCalculationforHighFrequency/SMPSInverter:http://tahmidmc.blogspot.com/2012/12/ferritetransformerturnscalculation.html

+6 Recommend this on Google

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310comments:

Yaghiyah January9,2013at2:44AM

Atipyougotsomegood informationherebut, thecolourschemeyouchoosearenotgoodfor readability, its reallybad..Trywhiteonblackinsteadiftheinverse(asyouhaveitcurrently).

Reply

Tahmid February7,2013at6:25AM

I'llkeepthatinmindandwillmakechangesifnecessary.Thanksfortheinput.

Regards,Tahmid.

Anonymous February22,2013at9:38PM

hellotahmidIhaveaquestionhere.Iambuildingahighfrequencyinverter.Iuseirfz46inthedctodcsectionandthedcvoltagestandsupgoodundera loadof300wattwhenIuseirf3205insteadwhichcanhandlemorecurrentthedcvoltagefallsoff to35vfrom165v.Couldthisbedefective3205fetsorIneedtochangecomponentstomatchtheirf3205.Thanksforursupport

Reply

Tahmid February22,2013at11:54PM

ItcouldbedefectiveIRF3205's.Butbeforethat,youshouldmakesurethattheMOSFETsareproperlydriven.Iftheyaren'tproperlydriventoturnthemfullyon,theproblemcouldliethere.So,addadrivercircuit(totempoleordiscretedriverbased,egTC427)andthentestagain.

Seehere:http://tahmidmc.blogspot.com/2012/12/lowsidemosfetdrivecircuitsand_23.html

Regards,Tahmid.


OhthankyouTahmidiwilltrythisdriverandletyouknowtheresults.keepthegoodworkgoing

PrasanthKumar January31,2013at7:01PM

HiTahmid,WhatistheroleofR3intheabovecircuit?

Regards,Prasanth.

Reply


HiPrasanth,

R3pullsuppin2tothelevelofVREFandisthususedasreferencevoltage(atpin2)fortheerroramplifier.

Regards,Tahmid.

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PrasanthKumar February9,2013at5:23AM

HiTahmid,Iamsorry ifumisunderstoodmyquestion. Imean if thevalueofR3 ismade0ohms, is itgoing tomakeanydifference? If Iamright, theinputofthecomparatorsarehavingveryhighimpedance.

Regards,Prasanth.

Reply


Yeah,itshouldn'tbeaproblem.Ifyouwon'tusepin2withanyvoltagedividercircuitandjustneedtoprovide5V,youshouldjustbeabletoconnectittoVREF.Theinputstotheerroramplifiershouldhavehighimpedance.

Regards,Tahmid.


hi,tahmidireallyneedyourhelpialreadymailedyousomeinfomaybeyoudidntchekitkindlyreplymeimintrouble.Regards:Waqas.(mah****[email protected])

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Checkyourinbox.

I'llansweryourquestionhereaswell:

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ThePIC,inasinewaveinverter,isusedtogeneratetheSPWMsignalsanddothe"housekeeping"tasksaswellbatterylowcut,overload,batteryhighcutandotherprotection,etc.Andyoualsohavethebenefitofnotbeingabletocopysomeoneelse'swork!

Regards,Tahmid.

abm February19,2013at2:31PM

thankstahmidforyourtutorials.

pleasecanyouguidemeonhowtouseTL431andoptocouplerasfeebackforsg3525.

thanks..

Reply


Hiabm,

I'mgladthatthetutorialswereofhelp.

I'lltrytowriteupanarticleonTL431andoptocouplerforfeedbackforSG3525.

Regards,Tahmid.

abm March6,2013at9:59AM

thankstahmidiwillbelookingforwardtothat.

youjustmadetheseSG3525aplaythingformeiamenjoyingit.ihaveplacedorderfroferriteinductorshopetostartlearningsmps,atleastenoughofsimulation.

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thanksforallyoureffortmayGodgrantyoumoreeaseofwisdomandknowledge(amen).


hitahmid""""

mynameismohamedmustafafromegyptpleasehelpmetodesignmypowerinverter>>>iboughtferritecoreETD34andifindthatat100khzthistransformergive321watt"fromdatasheet"canioperateirfz44nat100khzorthisnotadvisableandicalculatebutwith75khzthenumberof turnsofprimaryandsecondaryand i found it ::::Np=3 turnsandNs=96 turns>>>>what is the thicknessof thiswireofbothprimaryandsecondarymyemail::[email protected]

Reply


Hi,

321Wmentionedinthedatasheetistheabsolutemaximum.Youshoulduseitataconsiderablylowerpowerlevel.

Thethicknessofthewireoftheprimaryandsecondarywilldependonyourselectedpowerlevel.Rememberthatyoucan'tusetoothickwiresduetoskineffect,especiallysinceyou'reoperatingat100kHz.Don'tusewiresthickerthan26SWG.Then,usemultiple26SWGwirestohandletherequiredcurrent.

Regards,Tahmid.


forinput12v21A75KHZ250watt...foroutput310V0.9A75KHZ250watt...iwoundtheprimarywithwirethick=22SWGandthesecondarywithwirethick=27SWGIsthatsatisfied?

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thankyouforhelpingme

Anonymous March4,2013at4:37AM

IsthereanywaytomakedutycyclecontrolonSGICtobefrom1to99%?....Ibuiltfewcircuitsanditryedmanythingsbuticanreachthisrangeon300Khz.

Reply

Tahmid March4,2013at11:25AM

Areyouattemptingtocontrolthedutycyclewithoutafeedbackloop?

Anonymous March4,2013at2:52PM

hitahmid::mydesign:formyferriteETD34transformerforinput12v21A75KHZ250watt...foroutput310V0.9A75KHZ250watt...iwoundtheprimarywithwirethick=22SWGandthesecondarywithwirethick=27SWGIsthatsatisfied?thankyouforhelpingme

Reply


BeforeIgoontocheckforcurrentrating,IwillletyouknowthatSWG22wireistoothickforuseat75kHz.Skineffectwillplayalarge part and at high load, thewirewill overheat.Use quite a fewSWG26 in parallel tomake up thewirewith required current

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handlingcapacity.

Regards,Tahmid.


hitahmid:i purchase thecomponentofabovedesignbut i haveaquestion .... in theLC filter of theoutput the capacitor is 10micro ..1what is thewithstandvoltageofthecapacitor?????2whatisthespecificationofthiscapacitor?3haveyoupcblayoutofthisdesign?thankyouverymuch..........

Reply

Tahmid March11,2013at12:46PM

1)Makesurethevoltageishigherthanthemaximumoutputvoltage.A400VcapacitorwouldbegoodsinceIassumeyouroutputvoltagewouldbelowerthan330V.Ifit'shigherthanthatandcloseto400V,use630V.

2)Itisanelectrolyticcapacitor.TrytousealowESRcapacitor.

3)Unfortunately, Idon'thave thePCBdesign for this.Therearemany freePCBdesignsoftwareyoucanuse todesign thePCByourself.

ExpressPCB:http://www.expresspcb.com/expresspcbhtm/download.htmCadsoftEAGLE(freewarewithlimitation):http://www.cadsoftusa.com/downloadeagle/freeware/PCB123:http://www.sunstone.com/pcb123.aspxDesignSparkPCB:http://www.designspark.com/page/designsparkpcbhomepageDipTrace(freewarewithlimitation):http://www.diptrace.com/TINA:http://www.tina.com/English/tina/gEDA:http://www.gpleda.org/KiCadEDA:http://www.kicadpcb.org/display/KICAD/KiCad+EDA+Software+Suite

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ThereareotherfreePCBdesignsoftwareavailableaswell.

So,downloadone.Gothroughthemanualandstartusingit.

I'veusedExpressPCBandPCB123 (a littlebitofEAGLEaswell). I'dsay they'reprettygoodandcertainlygoodenough foryourpurpose.

Hopethishelps!

Regards,Tahmid.

TrentPalmer March7,2013at3:00AM

Hi,it's really an interesting topic "Using the SG3525 PWM Controller Explanation and Example: Circuit Diagram / Schematic of PushPullConverter".Asfarasmyconsolationitisanexcellentexplanation.Thankyoudear.Invertercharger

Reply


You'rewelcome!

I'mgladyoufoundithelpful.

Regards,Tahmid.


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hellotahmidkeepupthegoodwork.Ihaveaquestioniseeurcalculationsfortransformer.ifIcalculatetheprimaryturnsfora12dcsupplyto330vsayIwanttostepupmysystemto24dccaniusethesameprimaryturnsandadjust thesecondaryfor the330vormyprimaryturnswouldalsohavetobedifferentfor24v..Thankuforursupport

Reply


You should recalculate for 24VDC. Keeping the same primary turns means that you'll have twice the flux density you'll do for12VDC.

Regards,Tahmid.


hitahmid",,,,,plz..iwantPCBofthisdesign

Reply


Ihaven'tdesignedPCBforthis.TherearemanyfreePCBdesignsoftwareyoucanusetodesignthePCByourself.

ExpressPCB:http://www.expresspcb.com/expresspcbhtm/download.htmCadsoftEAGLE(freewarewithlimitation):http://www.cadsoftusa.com/downloadeagle/freeware/PCB123:http://www.sunstone.com/pcb123.aspxDesignSparkPCB:http://www.designspark.com/page/designsparkpcbhomepageDipTrace(freewarewithlimitation):http://www.diptrace.com/TINA:http://www.tina.com/English/tina/gEDA:http://www.gpleda.org/KiCadEDA:http://www.kicadpcb.org/display/KICAD/KiCad+EDA+Software+Suite

Reply

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Reply

ThereareotherfreePCBdesignsoftwareavailableaswell.

So,downloadone.Gothroughthemanualandstartusingit.

I'veusedExpressPCBandPCB123 (a littlebitofEAGLEaswell). I'dsay they'reprettygoodandcertainlygoodenough foryourpurpose.

Regards,Tahmid.

Anonymous March13,2013at7:33AM

hitahmidyouaredoingsomeexcellentworkiseeyourcalculationsforthenumberofprimaryturnsfortransformerfrom12VDCto330Vcouldyou please calculate from 24VDC TO 330V the number of primary turns because i dont fully understand the steps after setting out theequasionthanksinadvance

Reply


You should try it yourself by following the steps mentioned here: http://tahmidmc.blogspot.com/2012/12/ferritetransformerturnscalculation.html

Specifytheproblemsyouhave.Then,youcanlearnbydoingityourselfandIcanhelpyouifyouarestuck.

Regards,Tahmid.

Anonymous August12,2013at3:53PM

If ichangethenumberofTransformer turnratioaccordingly for24VDc ,should thevaluesofotherparametersremainsame???@tahmid

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hitahmid::mydesign:formyferriteETD34transformerforinput12v21A75KHZ250watt...foroutput310V0.9A75KHZ250watt...iwoundtheprimarywithwirethick=26SWG*4andthesecondarywithwirethick=35SWG*3whenapplying12vthecircuitgive310vbutthetransformermakenoisesound....isthisnoisesoundrefertoproblem?

Reply


Howloudisthesound?

Ensurethat thetransformerandwindingaretightandthat there'snoscopeforanysortof"movement".Dippingthetransformer invarnishshouldhelp.

Many a times, the reason for the audible noise is due to problems in the feedback circuitry. The oscillations in the unstablefeedbackcircuitrycausethenoise.Stabilizingthefeedbackloopshouldhelp.

Regards,Tahmid.


hiiiiiiiiiiiyouareverygeniusplz...ihavedone12vto310vcircuitandiwantcircuitdiagramofHbridgetoproduce220v,50hzpuresinewave...thankyouverymuch

Reply


Hi,

Thanksforthecompliment.

YoucanfindmanycircuitsifyousearchonGoogle.IthinkyoushouldfirstsearchonGoogle,ifyouhaven'tdonesoalready.Ifyouareunabletochooseoneduetoproblemsinunderstandingcriteria,etc,feelfreetoaskforhelp.

Regards,Tahmid.


ihadsearchoninternetbutuselesshaveyoucircuitdiagramfordrivinghbridge.....i'msosorryfordisturbingyou.....


Whatarethespecifications?Icanhelpyoudesignone.

Regards,Tahmid.


iwant250watt220v50hzpuresinewavecircuitdiagram....ihavedone12vto310vcircuitandiwantcircuitdiagramofHbridgetoproduce220v,50hzpuresinewave...thankyouverymuch


iwant250watt220v50hzpuresinewavecircuitdiagram....ihavedone12vto310vcircuitandiwantcircuitdiagramofHbridgetoproduce220v,50hzpuresinewave...thankyouverymuch


Pleasegothroughthisthoroughly:

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http://tahmidmc.blogspot.com/2013/01/usinghighlowsidedriverir2110with.html

Regards,Tahmid.


Hitahmid,yourblogisawesome.knowufromedaboard.haveaprojecttodoandnowjustneedtodopushpulldctodcconverterwhichconverts36VDCto311VDC.Icantsimulatethecircuitaboveandalsoneedtoimplementthiscircuit.Doesthiscircuitreallywork?needaferrite transformerbut cant implement this circuitwithout this transformer. meanshould selectproper ferrite first right?and then canimplement thiscircuit.Whicharticleshould readonyourblogabout ferrite transformercalculation?Myprojecthas1kVAoutputpower.Soferrite transformer must be 1kVA. My question is that how should start to implement this circuit ? because cant simulate it in proteus,multisim,ltspiceetc.

Reply


Hi,

Thanksforthecompliment.MayIknowyouredaboardusername?

Yes, the circuit works. But, for your project, don't just "copypaste" this circuit into the application. If you go through this entiretutorialonSG3525thoroughly,youshouldbeabletodesignthecircuityourself.

Regardingferritecoretransformercalculation,Ihavewrittenatutorialaswell.Youcanfindithere:

http://tahmidmc.blogspot.com/2012/12/ferritetransformerturnscalculation.html

Regards,Tahmid.


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Myedaboardusernameisfethiyeli.guesscanmodifythiscircuitformyrequirementsbutifhaveaquestion,askuinthisblog.Because of lacking of the ferrite transformermodel in simulation software, cant simulate it. So, do u have any idea how canimplement this circuitwithout simulating ?Should I calculate ferrite core transformer calculation first ? I dont knowwhich step shouldstart=)thnxagain.

Tahmid April2,2013at6:03AM

Youshouldstartwith thedesignof thePWMcontrollerstage, thenthedriverstageandthentheferrite transformerstage.For theferrite transformer, firstselectyourcoreandthencalculate thenumberof turns.Thendecidewhichwire touseandthenwindthetransformercarefullyandtightly.

Regards,Tahmid.


hitahmidiwantsmpsbatterycharger10A....iwantcircuitdiagram...canyouhelpme?

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YoucandesignoneusingSG3525andIR2110.GothroughthistutorialandtheoneonIR2110aswell.Alsogothroughthetutorialregardingtransformerdesignforhalfbridgeconverters.

http://tahmidmc.blogspot.com/2013/01/usingsg3525pwmcontrollerexplanation.htmlhttp://tahmidmc.blogspot.com/2013/01/usinghighlowsidedriverir2110with.htmlhttp://tahmidmc.blogspot.com/2013/02/ferritetransformerturnscalculation_22.html

Regards,Tahmid.

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hitahmidiwantsmpsbatterycharger10A....iwantcircuitdiagram...canyouhelpme?

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YoucandesignoneusingSG3525andIR2110.GothroughthistutorialandtheoneonIR2110aswell.Alsogothroughthetutorialregardingtransformerdesignforhalfbridgeconverters.

http://tahmidmc.blogspot.com/2013/01/usingsg3525pwmcontrollerexplanation.htmlhttp://tahmidmc.blogspot.com/2013/01/usinghighlowsidedriverir2110with.htmlhttp://tahmidmc.blogspot.com/2013/02/ferritetransformerturnscalculation_22.html

Regards,Tahmid.

Anonymous August29,2013at12:22AM

http://sandysplash.blogspot.in/


AftervisitingyourblogandreadingyourpostsIdidliketobecommunicatingwithyouhenceforth.

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Youcanemailmeatinfernorage(at)hotmail(dot)com

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Regards,Tahmid.


hitahmid...what'sthedifferencebetweensg3525&sg3525anifiplaceSG3525ANinsteadofSG3525atpushpullapplication??????????

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YoucanuseSG3525ANdirectlyforpushpullapplication.SG3525ANandSG3525arethesamechip.Differentmanufacturersusedifferentsuffixes,ANbeingoneofthem.

Regards,Tahmid.


DearTahmid, I'vefoundyourtutorialveryhelpful,especiallysincethedatasheetof theSG3525chip lackstheproper information,regardingthe associated circuit design. For example a profound information given by the Linear Technology, which comes along their buck/boostcontrollerchips,ispolesapartdifferentfromtheinformationmiseryofferedbytheSG3525manufacturers.Ithinkthoseguysoweyoualotofmoneysofar,asyourinformationservestheircustomers..Justonething,IMHO,yourvoltagedividerisslightlywronglycalculated.Whenyouhave that resistances, youractual resultant voltagewill beV=280x1/(56+1)=4.91V,not5.1,hence5.1x57=290.7V.Butapart from that,yourworkisexcellent.Thanksforyourefforts,justkeepitup,Iwishyouallthebest,mate,Alex,Krakow,Poland.(TemporarlyinLondon,UK)

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I'mgladtohearthatyoufoundmytutorialhelpful.I'mhappytobeabletohelpwheneverIcan.

Thanksforpointingouttheerror.I'vefixeditbyadjustingtheoutputvoltagerequirementsothattheoutputdesiredis290V.So,thecurrentcombinationworks.Thanksforpointingitout.

Yourcommentsandsuggestionsregardingtheblogandanyfurthermaterialarewelcomeandwillbeappreciated.

Regards,Tahmid.

star April6,2013at2:43AM

incapacitor8howmanyvlotageswillbeused.....?

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C8shouldberatedfor400Vormore.

Regards,Tahmid.

TrentPalmer April9,2013at3:59AM

Hello,TheblockdiagramofSG3525isfabulous.Andthedescriptionisreallyhelpfulforknowingthiscircuit.Thanksalotforsharingthisblog.DCtoACpowerinverter

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You'rewelcome.I'mgladthatyou'vefoundituseful.

Regards,Tahmid.

Anonymous April11,2013at9:54AM

Cool!thankyouveryverymuch!

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You'rewelcome.I'mgladthatyou'vefoundituseful.

Regards,Tahmid.


Greatresource!GreetingsfromSouthAfrica:)

Ihavejustonequestion.I'venoticedthatIamabletoonlyobtainamaxof50%dutycycleattheoutputsofAandBrespectively.CouldIjointheseoutputstogethersomewheretoobtainahigherdutycycle?Ifso,howwouldIachievethis?

Iamthinkingofusinganadderopamp?Whatdoyouthink?

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KindRegards.

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Hi,

The internal circuitry of the SG3525 is such that the outputs of A and B can only go up to 50% duty cycle. That is where theusefulnessoftheSG3525lies.Ifyouneedhigherdutycycle,youcoulduse2diodes,theanodesofwhichareconnectedtopins11and14,andthecathodeofbothareshorted.Thenyoutaketheoutputfromthispoint thecathodeof thediodes.Makesureyouuse ultrafast recovery diodes for higher frequencies. If you use this method, remember that you're blocking the pulling down /sinking ability of the internal totempole of theSG3525.So, you should use an external (totempole based or driver chip based)drivertodrivetheMOSFET.

Hopethishelps!

Regards,Tahmid.

gosthwhisper April15,2013at4:39AM

hieverybodyi'mafrenchsoidon'ttalkenglishverywell!ijustwanttoknowifwesuply18Vinsteadof12v,willitwork???thak'sregards

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Hi,

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I'vementionedthisinthearticleabove:

Pin15 isVCC thesupplyvoltage to theSG3525 thatmakes it run.VCCmust liewithin the range8V to35V.SG3525hasanundervoltagelockoutcircuitthatpreventsoperationwhenVCCisbelow8V,thuspreventingerroneousoperationormalfunction.

Pin13isVCthesupplyvoltagetotheSG3525driverstage.ItisconnectedtothecollectorsoftheNPNtransistorsintheoutputtotempole stage.Hence thenameVC.VCmust liewithin the range4.5V to35V.Theoutputdrivevoltagewill beone transistorvoltagedropbelowVC.SowhendrivingPowerMOSFETs,VCshouldbewithin the range9V to18V (asmostPowerMOSFETsrequireminimum8VtobefullyonandhaveamaximumVGSbreakdownvoltageof20V).Fordriving logic levelMOSFETs, lowerVC may be used. Care must be taken to ensure that the maximum VGS breakdown voltage of the MOSFET is not crossed.Similarly when the SG3525 outputs are fed to another driver or IGBT, VC must be selected accordingly, keeping in mind therequiredvoltageforthedevicebeingfedordriven.ItiscommonpracticetotieVCtoVCCwhenVCCisbelow20V.

Ihopethatanswersyourquestion!

Regards,Tahmid.

Anonymous April16,2013at6:08PM

mysg3525isalwaysheatup.afterdheat,it(sg3525)getdamage&canttakereadingofdfrequencyatthegateofthemosfetoncethesourceisconnectedtotheground.plskindlyguidemeinrectifingthisproblem.avalreadydamagelike3sg3525ic

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Check thepowerconnections to theSG3525.Ensure thatpin16 (VREF) isn'tshorted togroundorVCC.Ensure thatnoneof theoutputsareshortedtogroundorVCC.EnsurethatVCCiswithinacceptablelimits.

RemovetheconnectionstotheMOSFETsalltogetherandthenchecktheoutputsoftheSG3525.Measureboththefrequencyandthevoltage.Checktheshapeusinganoscilloscope,ifpossible.

You might even have damaged MOSFETs that are damaging the SG3525. So, if the outputs seem to be correct without theMOSFETsconnected,replacetheMOSFETswithnewones.

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Hopethishelps!

Regards,Tahmid.


HiTahmid,I am trying your circuit out, I get 48.8Khz from pin 11 (output A) but nothing at pin 14 (ouput B).What could be the problem? I have justconnected the SG3525 chip to 12V. I have not connected this to a MOSFET driver of CFL circuit yet?Just tryin this chip first to get afrequencycloseto50Khz.Thanksforyourhelpinadvance?

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Haveyoudesigned thecircuitcorrectly?Exactlyas I'veshown?Didyoumakeanychanges? Ifyouhave,whatchangesdidyoumake?CanyoutrywithanotherSG3525?

Regards,Tahmid.


HiTahmid,greatblogandthanksforsharingthisvaluableinformation!!!lastnightItriedthiscircuitanditseemstoworkfine,butther10forfeedbackwasveryhot..

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Ihavejustonequestion:thenetformatofR10andR11is57kohm,thecurrentflowingis290v/57kohm=5.08mAmoreorless...thepowerdissipatedisP=R*I^2=57000*(5.08mA)^2=1.47Wisnottoohigh?

InThisconfigurationshouldIUsea1Wresistors?It'snotbettertoincreasethevalueofthenetresistanceandlimitthecurrentflowwhilemaintainingthesameratioofdivider?

forexampleR10=120KohmandR11=2.2kohmsothecurrentflowis290v/124.2kohm=2,33mAandthepowerdissipationis(2.33mA)^2*124200=0.67WSocanusethehalfwattresistors...Iamright?

GreetingsfromItalyPier

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Yes,1.47Wisalittlehigh.Butyoucanuse3Wresistorssafely.1Wresistorswon'tdo.Youneedtoselectaresistorwithapowerdissipationcapacityhigherthantheactualmaxdissipation.Twicetheactualdissipationisagoodfigure.Andthat'swhyImentioned3W.

Yes, you can use larger resistance to lower the current and thus the power dissipation. If you get a 0.67W power dissipation(calculated),thenyoushouldusearesistorwithapowerdissipationcapacityofatleast1W.

RememberthatthisisforR10.R11won'tgethot.

Hopethishelps.

Regards,Tahmid.


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Thanks....:)Pier


I havemade circuit as per your procedure but 25watt energy saver is notworking properlymaking fluctuatingwhile i am using 12v 3ampchargertoswitchoninverter.Youarerequestedtoexplainwhybulbisnotworkingproperly.

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My first suspicion is that theoutput voltage is too low.So, before checking for other things, useahigh voltageDCvoltmeter tomeasuretheoutputvoltage.

AlsoyoumaywanttouseanoscilloscopetochecktheoutputsoftheSG3525toobservetheoutputpulsesanddetermineiftheyareok.

Postyourfindingsandthenwemayproceedtofixingtheproblem.

Regards,Tahmid.


iamusingetdcore.....

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WhichETDcoreareyouusing?egETD34,ETD39,ETD44,etc.....

Whatfrequencydidyouselect?

Howmanyprimaryturnsdidyouuse?Howmanysecondaryturnsdidyouuse?

Whataretheinputandoutputvoltagespecificationsyouhavedefined?

Regards,Tahmid.


tahmidplzreplyveryquickly.....andthanksalsowillbeforsupporting.....

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Iamextremelybusywithmyexams.KnowthatIwillreplytoyourpostsandwillbegladtodoso.Pleasebepatient.Thanks.

Regards,Tahmid.


pls.mymosfetisburninout.wotshudido

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Could youdescribe your situationwithmoredetails?Specifications?Circuit connections/ configuration?Transformer core?Turnsused?

Withoutknowingthese,there'snowayIcantellyouwhyyourMOSFETsareburning.

Regards,Tahmid.


mycoreisETD44...igiveninprimaryturns4+4...andinsecondaryturns200+200...sothenyoutellmeamiright?

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Whatisyourdesiredoutputvoltage?Whatistheinputvoltage?Didyouusefeedbackforoutputregulation?

Youransweringtheabovequestionswillhelpdeterminewheretheproblemlies.

Regards,Tahmid.


Anotherproblemyoumayhaveisthatthe"softstart"maybetooslow.Whatisthevalueofthesoftstartcapacitorthatyouused?


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amusingsg3524.rt=20Pot,ct=1nf.100khzfrequency.transformeree42.primary=4..0..4,sec=66turn.mosfet=75N06.frompin11&1410ohmand1ktodground.dutycylearud51%.plsyismymosfetburninout.amgettinfrustrated.ioptforsg3524bcusmysg3525keepsburnathighfrequencyi.e100KHZ

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Tahmid May17,2013at9:16AM

Therecouldbemanyreasons.

Ensurethatyou'vegotagoodenoughdriverinplaceandthatyou'vegotsufficientdeadtime.

The 51% duty cycle seems erroneous, if it's on one output. If both outputs have 51% duty cycle, that's what's causing theMOSFETstoburn.

Regards,Tahmid.


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star April21,2013at12:02PM

tahmid...icheckdotheirinverteroutputvoltageis240V.....

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ForaCFL,thatcouldbetoolow.Ofcourseitdependsonthebulbtoo.Iwouldrecommendyouincreasetheoutputvoltagetoabout

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280V.

Regards,Tahmid.


ThanksTahmid,ItriedanotherSG3525chipanditworked.Cheersbrother.

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That'sgreat!

mj April22,2013at3:39PM

amusingsg3524.rt=20Pot,ct=1nf.100khzfrequency.transformeree42.primary=4..0..4,sec=66turn.mosfet=75N06.frompin11&1410ohmand1ktodground.dutycylearud51%.plsyismymosfetburninout.amgettinfrustrated.ioptforsg3524bcusmysg3525keeps

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burnathighfrequencyi.e100KHZ

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Use a goodMOSFET driver circuit between theSG3525 and theMOSFET. This is critical, especially at higher frequencies like100kHz.YoucandesignasimplecircuitusingdedicatedgatedriverlikeTC427.Youcanalsousesimpletransistors.

Refertothis:tahmidmc.blogspot.com/2012/12/lowsidemosfetdrivecircuitsand_23.html

Regards,Tahmid.


iwanttodesigna50hzpuresinewavewhichhas10Vpeaktopeakoutputandaround100mAouputcurrent.pleasetellmethecircuitforthatandtheexactspecificationsofallcomponentsrequired.(ItriedmakingitusingphaseshiftoscillatorusingBJTbutfrequencywouldnotcomebelow150hz)PLZHELP

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Forsuch lowpower,usingamicrocontroller+bridgewouldbeoverkill.Therearemanysinewaveoscillatorcircuitsyoucan findonline,withBJTsandalsowithoperationalamplifiers.

Regards,Tahmid.

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Anonymous May5,2013at4:24AM

Tahmid,moregreasetoyourelbow.Plzcanyouexpliantomethecompensationnetworkandhowitworks.AnotherthingIwanttoknowisifIcanusetheoutputfromthetransformerdirectlytoappliancesassumingitisapproximately230V,50Hz.Plzreply.Thanks

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There'squiteabitIhavetolearnaboutcompensationnetworkbeforeIcanwriteatutorialaboutthat.

Yes,youcanconnecttheoutputdirectly.Adda1uFcapacitoracrosstheoutputforfiltering.

Regards,Tahmid.


HiTahmidwillcurrentflowthroughR5i.e2.2k??

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Therewillbeaverysmallamountofcurrent.YoumightfindithelpfultothinkofR5asa"pullupresistor".

Regards,Tahmid.

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DinaHady May13,2013at1:25PM

Electronics is a study of flow of electrons in electrical circuits. Youmade some good points about electronics. I have read your post it isgenuineandhelpful.ThanksAerospaceandElectronicsSystems

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Nomi May16,2013at1:26AM

DearTahmid,

IhavefollowingissuesinSMPSInverter.

Iammakinga1KVAsystem.IsETD49enaughfor24Vto350VDCDCBoostConverterworking@40KHzPushPull?Whatarethestepstocalculatenumberofturnsforhighfrequencytransformer?Ihavecalculatedaccordingtomentionedcalculationbutitisnotworkig.

ThanksinAdvance

RegardsGapoo

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Fortransformerwinding,refertothis:

tahmidmc.blogspot.com/2012/12/ferritetransformerturnscalculation.html

ETD49couldbeenough.YoucouldmoveuptoETD54.

Regards,Tahmid.

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Nomi May20,2013at8:04AM

Igot350VatoutputbutasIputanysmallloadoutputreducestozero.

Tahmid June21,2013at5:12PM

DotheMOSFETsheatupandgetdamagedaftertheloadisputon?

NandulalGavali May16,2013at9:01AM

HiTahmid,Iamdesigningsinewaveinverter.Input:8Vto16VDCBatteryPushpullOut:325V/0.5AFullBridgeInverter:230V/50Hzoutput

Now,inpushpull,howtouseSG3525inisolatedvoltagefeedback?Canyoushareanyideaorcircuit?Iwanttoregulate325Vbutwithisolation(anyisolatorwith100%or200%CTR).

RegardsNKG

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Youmayuseasimpleauxiliarywinding(thatcanalsobeusedtopowerthesecondarysidecircuits)alongwithoptocoupler+TL431forisolatedfeedback.

PC817BhasaCTRbetween130%to260%.PC817C:200%to400%.PC817D:300%to600%.

Regards,Tahmid.

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Anonymous May19,2013at12:23PM

plsineedurhelp,oneofmymosfetgethotfastthantheotherone

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WhichMOSFETsareyouusing?AreyoudrivingthemdirectlyfromSG3525?WhatisthefrequencyyousetforSG3525?Didyouuseadeadtimeresistor?


amusingirfp250.amdrivingitfromthesg3525.65khzfrequencyandnodeadtimeresistor.iconnectedpin7directlytopin5


Useasmalldeadtime.

YoumayneedtouseadrivercircuitfortheMOSFETs.Youcanuseasimpletotempoledriveroradedicateddriverbaseddesign.Takealookhere:

tahmidmc.blogspot.com/2012/12/lowsidemosfetdrivecircuitsand_23.html

Regards,Tahmid.


thanks.nowamdrivingthemosfetfromatotempoleandalso39ohmbetweenpin7and5.havealsoreduceddfrequencyto31KHZbutafter5minuteswithoutloadbothmosfetwillstartgettinghotslowly


Haveyouensuredthatthetransformerhasbeenwoundproperly?

YoumightneedtousesnubbersyoumightbefacingproblemsduetospikesattheMOSFETdrains, iethetransformerprimary.UseanoscilloscopeandobservethewaveformattheMOSFETdrains.

Regards,Tahmid.

Anonymous June22,2013at9:26AM

idon'thaveaccess tooscilloscope.isavagemy transformer froma t.vwithouthavingany informationon it.so i rewinds itby justassumingitaparticularcore.pleasewhatcanidonowsinceidon'thaveaccesstooscilloscope.

Tahmid July20,2013at5:00PM

Useasnubbercircuit.Withoutanoscilloscopeitwillbedifficulttounderstandthenatureofthespikes,butyoumayexperimentwithdifferentvaluestofindwhichworksbest.

Doesthetransformeryouusehavealargegappedcores?


avusesnubberstilldsametini.e47ohmresistorden1nfcap.btweniputcapof100nfmyresistorsburnsout.amusing12v88ahbattery.notenofeedbackyet.


anothertinagainisthatweniswitchonmycircuitwendmosfetisnothot,idoavlikeathousandvoltforsomesecondsbeforeitdropstolike7hundredsomethingvolt

Tahmid August8,2013at2:29AM

Thatvoltageiswaytoohigh!

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I thinkyouhaveaproblemwithyour transformerwinding.The leakage inductance is toohighand thatcontributes tohighspikes.Also,thewindingsmaynotbeperfectlysymmetrical,causingtheheating.

Try with snubber values of about 56 ohm resistance (2W5W depending on how much heat you dissipate) and 68nF 100Vcapacitance.Thenexperimentfurtherwiththeresistorandcapacitorvalues.

Regards,Tahmid.


HiTahmid,

greatwebsite!savesmealottime....

so, Idon't thinkyousawmy lastpostaboutauc2845 ic, looks like theycall ita flybackconverter (what Iwasbuilding),simpledesignbutsincemyecoretransformersmadeanoyingnoise(can'treallyexplain it,nothingtodowith losewindingswithtoroidstherewasnoproblem)evenat48khzspecialywithlitleornoload,under"heavy"loaditwasbetter,andafterremovingsomesecundarywindingsitwasalsobetterbuttheoutputvoltagewasdroppingunderhigherload.

SoIstartedbuildingthe3525circuitMygoalwasstill24>+200VDC

Imadeeverythinglikeyourschematicanditworked!ExceptIputinalm7818forfeedingthe3525andmosfets.Sincetheefficiencywascrapwithafirsttest(Iusedthe1N4007forthebridgerectifier),maybetheoutputcapacitorof470uF450Vistobig,theywerealsogettinghot.IswapedthediodesforBuy27.

So now I got 209V 0.63A output@ 75% efficiency and 208V 0.17A@ 74% efficiency. No load (only about 1W for the voltage sensingfeedbackresistors)thecircuitdrawsabout2.2W.I'musing2times7turnsprim,and70turnssec.Somyturnratioisabitonthehighside,maybeIcouldremove5turns.Thefets250v38A0.075mohmandarenotwarm,mountedonabigheatsinkImustsay.@0.2Aoutputthetransformerisnotgettingwarm,at0.6Athewindingsarewarmingup,butthecorestayscool.(with48khzIcouldevenbesavewithonly3primturns)I'musing0.28mmwire for the transformer. I think I need toparallelmorewires formyprimary coil since it is recomended touse3A/mmright?0.28mmistolowIguesssincemyprimpulls67A.I'mnotusingtheoutputriple/snubber?coilsoIwillexperimentlaterwiththat.

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NOw,Iwanttohighermyefficiency,sinceI'mlosingalmost45Wwithanoutputof130W,theremustbesomethinginthechainthatislosingalotofpower!NowIcantnoticepartsthatareheatingupmorethantheyshould,anytips?Mymultimeterisdecentandmadenocalculationmistakes.

Btwisitpossibletomakeacurrentprotectionwiththe3525ordoIneedamorecomplicateddriver?

thanks!

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UseadrivercircuitbetweentheSG3525outputsandtheMOSFETgates.

Bringtheprimaryturnsdownfrom2x7turnsto2x4turnsor2x5turns.Adjustthesecondaryaccordingly.

0.28mm^2iswhat,SWG24,right?Withaprimarycurrentof67A,use3xSWG26wires inparallel.Thatshouldhelp improvedcurrenthandling+reducedlossesfromskineffecy.

Use ultrafast diodes at the output.What are the specifications for BUY27? I regularly useUF4007 diodes.DONOT use regularrectifierdiodeslike1N4007astheyaretooslow.Justtakealookatthereverserecoverytimeinthedatasheet!

Reducetheoutputcapacitancetoabout100uF.

Trywiththesechangesandletmeknowtheresult.Goodluck!

Regards,Tahmid.

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For(over)currentprotection,youneedtouseanexternalcircuit.TheSG3525itselfdoesn'tprovideovercurrentprotection.UseanexternalcircuitthatshutsdowntheSG3525whenthecurrentistoohigh.Youcanuseashuntresistor,halleffectsensororcurrenttransformerforcurrentsense.

Regards,Tahmid.

QunhDng July31,2013at1:07AM

HiTahmid,

Iwantmyoutput230VDC,500realwatt(50Ainput),soithinkishouldwindpri3turn+3turn,sec75turn.Canyoutellmehowtochoosecooperwireforpriandseccoils?

Bymycalculation,iwind72x26SWGwiresinparallelforpri,butduetoskineffect,ithink65x26SWGisOK!

Plzhelpmethisdoubt.

Regards,

Quynh


72 x 26 SWG is not required! If you can use that many, 72 or even 65, there's no harm. It's even better due to lower windingresistance.Butabout1520x26SWGshouldbemorethanenough.Ofcourse,theactualcapacitywilldependonthespecificwireitself,duetoitspropertiessuchasinsulatingmaterial,etc.So,oversizingmayactuallybeagoodideaifyouhavespace.

Forfrequencieslessthanabout100kHz,Idon'tthinkyoureallyneedtoworryaboutskineffectforSWG#26wire.

Regards,Tahmid.

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Hi,canIputapwmsignalontheshutdownpin?

( forasolarproject Iwant tocontrol theoutputpower,becausethe loadwillbeabatteryandIdon'twant the inputvoltagetocollapseorgolowerthanacertainlevel,sinceitispoweredbyasolarpanelabout5timestheoutputvoltage)

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Don'tapplyPWMsignals to theshutdownpin. Instead, I think, it'llbebetter if youuse theMOSFETs for theswitchinganddrivethem off when required and back on when required, ie control the MOSFET on/off via the drive signals instead of using theshutdownpin.

Regards,Tahmid.

TrentPalmer June5,2013at2:35AM

Hello,thankyoufortheinformationaboutthistypeofpowerinverter.I lovetoreadthispostbecauseit isveryusefulandeasytounderstand,afterreadingthispageIwillseetheotherpagesofthiswebhopefullyhavealotofgoodinformation.Powerinverters

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I'mgladyou'refindingmypostshelpful!

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NoahTJ June9,2013at4:17PM

What is the formula for calculating the value of feedback resistors supposing the ferrite transformer would be wound to produce lets say340v??

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It's the same formula as the normal voltage divider formula. Take Vin to be 340V and Vout to be 5.1V (as that's the referencevoltageused).Makesureyouuselargeenoughresistancessothatcurrentthroughtheresistorsisverysmall.

Regards,Tahmid.

Anonymous June9,2013at11:53PM

hiTahmidwhypin1connecttoinverteroutput?canweusewithoutconnectithowselectprimaryandsecondarywirethick?

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Thegivenconnection(withpin1connectedtooutputviatheresistors)providesfeedback.Pleasegothroughthearticlethoroughlyandyoucanunderstandthefeedbackimplementation.

Youcanavoidconnectingpin1asshownifyouchoosenottousefeedback.

The thicknessof theprimaryandsecondarywiresareselecteddependingon thecurrent through them.Usemultiple thinwires inparalleldon'tusewiresthataretoothick.Google"wireskineffect"andreadaboutittoknowmoreaboutthis.

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Regards,Tahmid.


Hi,Dear

Icantfindsg3524orsg3525ProteouseliberaryCanupleasehelpinthis?i'llbethankfull

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Takealookonthispage:http://320volt.com/proteusisissmpspwmentegremodellerilibrarydosyalari/

Thelinksgivenontheabovementionedpageare:

https://dl.dropbox.com/s/z6axv7owsnt73ax/proteusisissmpspwmentegremodellerilibrarydosyalari.rar?dl=1

https://rapidshare.com/files/2895824845/proteusisissmpspwmentegremodellerilibrarydosyalari.rar

http://www.mediafire.com/?0sz11ua84ah3v2d

http://320volt.com/wpcontent/uploads/2011/10/proteusisissmpspwmentegremodellerilibrarydosyalari.rar

Regards,Tahmid.


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Aoa!howtodesignfeedbackofthegivencct.

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Thecircuitshownhasnonisolatedfeedbackimplemented.Pleasereadthearticlethoroughlyandyoucanunderstandthefeedbackimplementation.

Regards,Tahmid.


Aoa!imeanhow todesign feedbackcompensationb/wpin1and9.orgivegeneralvaluesof resistorandcapacitorb/wpin1and9.alsocanugivemereferenceforunderstandingthistopic.thanks


Ifyouwanttounderstandfeedbackcompensation,referto"SwitchingPowerSupplyDesign"byAbrahamPressman.Tolearnaboutquicklyimplementingit,referto"PowerSupplyCookbook"byMartyBrown.

Regards,Tahmid.

akeem2203 June25,2013at4:53AM

PleaseTahmid, Idesigned50HZsinewavesignalusingOPAMPandcarriersignalof20KHZusingOPAMP.Canyou tellmehow touseSG3525asPWMwiththistwosignalstoproduce50HZPURESINEWAVEsignalforinverter.BecausethisSG3525hasshutdownpinandthepinwillbeusedforoverload,batterylowandACONshutdown.

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SG3525shouldnotbeusedforgeneratingSPWMsignals.Youcanusetheanalogmethodasyoudescribed.ButbetterwouldbetouseamicrocontrollertogeneratetheSPWMsignals.Takealookatthese:

http://tahmidmc.blogspot.com/2011/01/generationandimplementationofsine.html

http://tahmidmc.blogspot.com/2012/10/smartsinesoftwaretogeneratesine.html

http://tahmidmc.blogspot.com/2012/10/generationofsinewaveusingspwmin_10.html

http://tahmidmc.blogspot.com/2012/10/600w50hzsinewaveinvertertest.html

http://tahmidmc.blogspot.com/2012/11/feedbackinsinewaveinverterpic16f.html

http://tahmidmc.blogspot.com/2013/02/demystifyinguseoftablepointerin.html

http://tahmidmc.blogspot.com/2013/02/generationofsinewavewithouteccp_16.html

http://tahmidmc.blogspot.com/2013/02/sinewavegenerationwithfastpwmmode_2525.html

http://tahmidmc.blogspot.com/2013/07/sinewavegenerationandimplementation.html

Hopethishelps!

Regards,Tahmid.



EmbSysDev June27,2013at5:55PM

HiTahmid,

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Niceblog.YoudidnotneedasnubbercircuitforyourMOSFETs?

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Inmost ofmy experimental lowvoltage inputDCDC converter circuits I did not need snubbers as the peak spikewas not highenoughtodamagetheMOSFETs.However, forhighpowercircuitsandfor finalcommercialproducts,asnubbercircuitshouldbeused.

Regards,Tahmid.

EmbSysDev June28,2013at3:28AM

AndIdowish,youwouldconsiderusingablackonwhitebackgroundforyourblog:)

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Ididgetthatsuggestiononcebefore.HoweverI likethewhiteonblackbackgroundandmostpeopledon'tmindit.However, Iwillkeepyoursuggestioninmind.

Withthanks,Tahmid.

Anvaya June28,2013at5:44AM

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DearTahmid.

Canyoupleaseprovidetheschematicfor300VAInverter.

Regards,Anvaya

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Ican'tgiveyouanycompletecircuit,butgothroughthese:

http://tahmidmc.blogspot.com/2013/01/usingsg3525pwmcontrollerexplanation.html



http://tahmidmc.blogspot.com/2013/03/outputinductancecalculationforsmps.html

http://tahmidmc.blogspot.com/2013/02/nchannelmosfethighsidedrivewhen.html

http://tahmidmc.blogspot.com/2012/12/lowsidemosfetdrivecircuitsand_23.html

http://tahmidmc.blogspot.com/2013/05/debuggingbridgetipstosuccessfully.html

http://tahmidmc.blogspot.com/2012/12/learningsmpshardway.html

Hopethishelps!

Regards,Tahmid.



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Aoa!ihavecoresaturationproblemwithmypushpullconverter.Bynow,ihavetesteditwithoutload.plzguidemeaboutitssolution.

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Howdoyouknowthattheproblemiswithcoresaturation?

Providemore details of the PWM section, theMOSFET drive section, theMOSFET connection section, andmost importantly,transformerparametersandspecifications.

Regards,Tahmid.

TrentPalmer July2,2013at1:41AM

Hi,The topic about Using the SG3525 PWM Controller Explanation and Example: Circuit Diagram / Schematic of PushPull Converter isfabulous.It'sagoodpost formebecause I amalways interesting to knowabout the Inverters,it's shellingandproducts .ThanksSir for thisusefulpostwhichisverymuchimportantforme.ThanksagainDCpowerinverter

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Anonymous July16,2013at9:24PM

helloTahmidkeepthegoodworkgoing.Ihaveaproblemwithamodifiedsinewaveinverteribuilt.Itsrunningat60hzontheoutputwheneveriplugappliances in it like tv radio fridge lightsetc the frequencyat theoutput remainsat 60hzbutwhen i pluga fan into it I seemymetershowingfrequencychangelike158hzanditisnotstableifIuseonelegofmymeterandtouchonelegoftheacoutitreads60hzbutaccross

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twolegsIseeanincreasebutthisonlyhappenswithafanplugedin.Pleasehelpmehere.Thankyou

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Doesthefanoperateproperly?Doesitrunsmoothlywithoutanyunusualnoise?

Whatmeterareyouusing?

Canyoutestwithotherfanstooandposttheresult?

Anonymous July22,2013at9:34AM

thank u Tahmid for your support. The fan runs smoothely just the usual low hum beingmodified sine wave I am using a flukemultimeter. I triedotherfansandthesamethinghappensbut if Ihavethetvplugedinat thesametimewiththefanIdontseeadifferenceinthepictureonthescreenoroperationofthetvsoIdontknowhowtoexplainthissoIasku.Thanku


Itcouldbethateverything'sokaybutthemeterisgivingsomekindofafalsereading.Maybethefancontributestothissomehow.I'mnotsurebutit'spossible.Likeyousay,everythingelseseemsfine.

See if you get the same resultswith a different fan.See if you get the same resultswith a differentmeter. If possible, see theoutputwithanoscilloscopeandseeiftherereallyisachangeintheoutput.Thatshouldclearthingsup.

Regards,Tahmid.

RAHUL.R July20,2013at9:14AM

helloTahmid,iamrahullaluaelectronicsEngineeringDiplomastudentfromtrivandrum,inIndia,nowiamtryingtomakea12Vdc/24Vdc500Wtransformerlesspuresinewave(pwm)inverterformyclassroom,butidon'thaveanygoodcircuit,socanyougivemeagoodcircuit??iamwaitingforyourfavorablereply(myemailid:[email protected])

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thankyou....

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Ican'tgiveyouanycompletecircuit,butgothroughthese:

http://tahmidmc.blogspot.com/2013/01/usingsg3525pwmcontrollerexplanation.html



http://tahmidmc.blogspot.com/2013/03/outputinductancecalculationforsmps.html

http://tahmidmc.blogspot.com/2013/02/nchannelmosfethighsidedrivewhen.html

http://tahmidmc.blogspot.com/2012/12/lowsidemosfetdrivecircuitsand_23.html

http://tahmidmc.blogspot.com/2013/05/debuggingbridgetipstosuccessfully.html

http://tahmidmc.blogspot.com/2012/12/learningsmpshardway.html

Hopethishelps!

Regards,Tahmid.

QunhDng July23,2013at10:32PM

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ihavesimplequestionthatthiscircuitisdesignedfor12Vinput,whatchangesshouldimadefor40Vinput

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Youneedtoaddalowvoltageregulator(egfor12Voutput)tosupplytheSG3525.Therestisprettymuchthesame.

Youmaywanttoconsideraswitchingregulatoroveralinearregulatorforlowerlossesandhigherefficiency.

Regards,Tahmid.

QunhDng August8,2013at4:35AM

HiTahmid,

CanyoushowmehowincreaseefficencyofDCDCconverterSG3525andreducetemparatureoneachMOSFET?

IthinkthatishouldforcedturnoffMOSFETwithnegativevoltage?Butihaventkonwnyetwhatishoulddo?

Plzhelpme.

Bestregards,

Qunh.

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1) Use MOSFETs with very low RDS(on) to reduce onstate resistance, thus reducing power loss and increasing efficiency. If

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necessary,connectMOSFETsinparalleltoreduceRDS(on).Thisreducesconductionpowerlosses.

2)Negativevoltageisnotrequired.ButuseagooddrivercircuittoturntheMOSFEToffasquicklyaspossibleandtoensurethattheMOSFETisturnedfullyonwhenitison.

3)Don'tusetoohighafrequencythattheswitchinglossesareincreased.

4)Usegoodtransformerswithlowleakageinductance.

Hopethishelps.

Regards,Tahmid.


Bro,urblogisveryexellent,mayALLAHrewarduforureffort,ihavetoaskthatifiuse4mosfets(insteadof2dueto largepower) thenhowshouldiconnectthem???plzreply

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YouhavetoconnectMOSFETsinparallel.ConnectthedrainsoftheparalleledMOSFETstogetherandconnectthesourcesoftheparalleledMOSFETstogether.UseindividualgateresistorsforalltheMOSFETsandconnectthemalltothecommoninputsignal.

Ifyouhave4MOSFETsinsteadof2,thatmeansthatyouhave2MOSFETsparalleledineachjunction.

Regards,Tahmid.

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how to calculate the valueof inductor ( L1) ???andwill therebeanydifference ifC5,C6arenot used?andwhat is thepurposeofC8??actuallyimnewinpowerelectronics.canuplzhelpRegardsQamar

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C5andC6mustbeused.C6shouldbeplacedasclosetotheSG3525aspossible.

C8istheoutputbulk/filtercapacitor.

Forcalculationoftheoutputinductor,gohere:http://tahmidmc.blogspot.com/2013/03/outputinductancecalculationforsmps.html

Regards,Tahmid.


thanksalotsir:)


howdoimakemyoutputdutycycle50%?weniconnectoneendofmyoutputpin11orpin14,thenoneendtothenegativeterminalofmybattery,ddutycycle isalwaysaround50.9%.butwheni testbothoutputpin11&14togetherwithoutput itonthenegative,isalwaysaround52.2%.anysolutionwhyisnot50%?mymosfetisgettinhottoo

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Anonymous October30,2013at7:48AM

hello,ineedtosetmydutycycleto58%howdoidothis?

DirleanRsantos August21,2013at3:49PM

HiYourblogisverygood.ThetimesIhavebeenusinginmylearning.congratulationsforyourblog.RegardingtheSG3525amwonderinghowdoIconnectseveralcontrollerstosynchronizethem

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Tahmid August25,2013at2:18PM

Ihaven'tyettriedtosynchronizemultiplecontrollers.MayIknowwhyyouaretryingtosynchronizemultiplecontrollers?

Iwilltakealookaroundandexperimentonthis,andI'llgetbacktoyou.

Regards,Tahmid.

DirleanRsantos September4,2013at2:22PM

I'mtryingtomakeaconverterusingSG3525asPWMcontrollerforawindgeneratorthatwillworkwithvariablevoltagefrom80to240VACandtheoutputvoltageoftheconvertershouldbe50Vdcpowertonotbeveryhighineachmodule,thetimingwouldbeforconnectingmodules inparallel convertersputwithout timing theydonotworkperfectlypwma feedback influenceon theother. Iawaitanyideathanksforyourattention...

DirleanRsantos October7,2013at8:15AM

Hi,IfoundadatasheetwheretimingisshownitcallsTC35C25ofTELCOM.IfthisisalsothedoubtsIhavehelpedsomeone...

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AnvayaDesignHouse August24,2013at8:04AM

HiTahmid,

Howtogetsinewaveoutputwiththisckt.Withoutusinganymicrocontroller.

Thesinewavefrequencyshouldbe50Hzonly.

Becausewiththismodifiedsinewavetheinductiveloadswillnotwork.

Likefansandmotorsarenotworkwithmodifiedsinewave.

So,canyoupleasetellme.

Regards,Anvaya

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Youcan'tgetsinewaveoutputwiththiscircuit.Youshouldlooktouseamicrocontrollerforthispurpose.Ifyoudohaveaproblemwithusingmicrocontroller(egifyouaren'tsureinyourabilitiesinusingmicrocontrollers),thenyoucantrytoimplementsinewavegenerationwithoutmicrocontroller,usingcircuitssimilartothis:

http://www.wpi.edu/Pubs/Eproject/Available/Eproject042507092653/unrestricted/MQP_D_1_2.pdf

Regards,Tahmid.


ThankuTahmid.

Butthisconceptisworkpractically.

Thisisjustaacademicproject.WearethemanufacturingCompany.Inlargevolumesthisdesignisnotcorrectchoice.

Canyoupleasetellmethathowmuchefficientthisdesign.

Isthereanypracticaleissueswithdesign.

IsawsomewhereelseBubbaOscillatorisnotefficient.Andthishavingmaxcurrentcapacityof200mAonly.

ButformyapplicationInput=12VDCoutput=230VAC,50Hz,ItisgoingtoruralareassoinIndiaruralareashavingInductiveLoadsonly.

ItshouldWorkwithinductiveloads.

Andmoreovertheabovedesign(SG3525)isusefulforInductivedesigns.WithHighfrequencyDCVoltages.

Inhttp://tahmidmc.blogspot.in/2012/12/ferritetransformerturnscalculation.htmlyouhavementionedthatonlynumberofturns.

ButwecantabletoconstructFerriteTransformerwithoutknowinginductance.

So,canyoupleasetellmetheinductance.

Sofinallyineed2clarificationsHighFrequencyDCissuitableforInductiveloadsornot&Formulaforinductance.

Thanksinadvance.

Regards,AnvayaDesigns


Youcanbuildprettyhighpowersystemswithit.ButIthinkI'vereadthatBubbaoscillatorsareunstableandtakequiteanefforttogetstable.

Forcommercialapplicationswithhighefficiency,Ithinkyourbestchoiceistousemicrocontrollers.Gotothispage:

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http://tahmidmc.blogspot.com/p/blogpage.html

Scrolldownto"SPWMandsinewavegenerationandinverter:"andseealltherelatedarticles.I'vegotloadsofarticles/tutorialsonsinewavegenerationandimplementationusingtheMicrochipPIC,AtmelAVRandtheMicrochipdsPIC.

SG3525isusedforjustregularPWMforobtainingsquarewave/quasisinewaveoutputs.

For forwardtype converters, such as forward, pushpull, bridge, what's important is the number of turns and the relevant fluxdensity.Don'tworryabouttheinductacne.

Idon'tget this lastpart: "So finally ineed2clarificationsHighFrequencyDC issuitable for Inductive loadsornot&Formula forinductance."Couldyouclarify?

Hopethishelps.Tahmid.


HiTahmid,

Inductiveloadsareworkwithhighfrequencyinverterornot.

Inductiveloadsmeanssealingfans.HighfrequencyinverterdesignbasedonSG3525.

CanwedesignInverterwith50HZfrequencywithSG3525ornot.

Ifeelthat,ifwedesigninverterat50HZtheferritecoreisnotsuitablefordesign.

Sopleasetellme..

Thanksinadvance

Anvaya

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HelloTahmidIhavebennfollowingur infoalloverthenetandImustsayIappreciateyoursupport. Ihaveaquestionhere. Iambuildingapushpull transformeroutput inverter.Thecircuituses1kasgateresistorsand10kfromgatetosource.Iwanttouseabout24 irf260fets. Iwanttoknowifloweringthegateresistorfrom1kdowntoabouthalf(500ohm)ifthiswouldgivememorepowerfromthefets.Iamusingoneofyourtotemdrivercircuitstodrivethefets.Thankuforursupport

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DevonHoldeutine August27,2013at5:54PM

Tahmidcaniavoidconnectingthereftopin10..bcosiwill liketouseitwithothercontrolcircuitforshutdown...andplzcanumailmeawelldetails feedback loop complete circuit diagram using 4n35 with sg3524 and sg3525.i will need it as soon as possible [email protected]

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TD September16,2013at3:23AM

caniusethiscircuitforbothof24vand12viwatttomake12v24vto250vtransformerusingyourformulacanidoit

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Anonymous September16,2013at11:52AM

HiTahmid,

Youcanexplainforme10^9calculatorfrom?.andformulathick(Sorrymyenglishslightlyless.IusingGoogletrans,I'mfromVN).Ihopeyouhelpgoodwork

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Tahmid September21,2013at8:53PM

Hi,

That'sthetimingcapacitorCT.IusedCT=1nF(asmentioned).TheformulausescapacitanceinFaradsandresistanceinohmstogivefrequencyinHertz.SoIneedtoconvertfromnFtoF:

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1nF=10^(9)F.

Regards,Tahmid.

Anonymous September17,2013at10:48AM

hihowtoconvertthissg3525circuitto24v

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JonathanKambalada October7,2013at4:22AM

hiecansomeonehelpmewithexplainingthefrequencyformularcalculationsimhavingproblemsunderstandingit

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MuhammadHamid October8,2013at9:52AM

HyTahmid,ihopeyouwillbefine...iamhavingaprobleminmakinginverter.i'mmakinginverterusingtl494andsg3524.i'musingpushpulltopologytodrivetransformerandtl494todrivepushpullmosfetandsg3524todrivefullbridgemosfet...butthereisnofeedback.its justasimplecircuit.canyousendmethetl494andsg3524circuitwithproperfeedback.ihavesharedtheonlytl494circuitfile.linkishttp://rapidshare.com/share/[email protected]

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TD October8,2013at10:04AM

HiTahmidcanyoutellmehowtochangethiscircuitandFETfor24vicalculatetransformerfor24vbutthiscircuitnotwork24vFETburneverytimeisupply24vcanyouhelpmepleasemyemailtdilshan100@gmail.comthanksReply

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extrangero October15,2013at2:00PM

hithmidthanksforthisblogitisgreatandsousefull,onpin3syncthereisnothing?i'vetryedthisonproteusbutnothinghapennedandsoiconnectitto+vccanditworks,couldyoutellmeifitwasamistakeorcanyouexplainmeforwhatisthispin?thanks

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MubarakMusthafa October17,2013at3:26AM

HiTahmid,MynameisMubarak.Ihavebeensuccessfulinmakingthe310VDCwithyourcircuit.Ihaveastrangeproblem.Wheniconnectthe 310 VDC to a CFL bulb, myMOSFET is getting very hot and blowing. I havemade your circuit in 3 parts PCB, one is PWM stage,MOSFETStageandTransformerStageandlastoneisrectificationstage.Isthemosfetgettinghotbecauseihaveseparatedeachstageandconnectedthroughwire?HowtosolvetheMosfetheatingissue?

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MubarakMusthafa October19,2013at12:42PM

Iwasabletomakeitwork.TheproblemofMOSFETgettinghotandblowingisbecauseofafaultyCFL.Whenitriedwitha100Wbulb,itsworkinglikeacharm.:)Iamhappytoseegetthingsworkingaftersomuchstruggleinmakingitwork.

Anonymous October19,2013at12:55PM

howthisusetodrivedcmotor35vto180vfortreadmill.plcdrawacircuitforushowwilldoitthanks

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TawheedKibria October21,2013at12:16PM

greetings!!!Hopesoyourfine...

I,MohammadTawheedKibria. Ineedtobuildabuckboostregulatorusingamicrocontroller formythesiswork. for thisworktheregulatorsinputmayvaryfrom12Vto20Vwithconstantoutputat165V/150V.andmax.powercapacityshouldbe100W.Pleasehelpmetofindoutthework.

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extrangero October25,2013at6:59PM

hitahmidcouldyoutellmewhathappenifthefeedbackvoltageonpin1isgreaterthan5.1v?inthiscaseinyourexamplewhenthevoltageislessof290Vthedutycycleisincreasedbutwhathappenifthevoltagegoesupforexampleto300Vinthiscasethevoltageonpin1willbemorethan5.1Vinthiscasethedutycycleisdecreasedtoreducetheoutputvoltage?orwhathappeninthiscase?.thanksforyourtime.Regardsfromcolombia

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GhulamZainordin October26,2013at3:25AM

thisispushpullcircuitright?thiscircuitcanapplyforphotovoltaicsystem?imean,thesupply12VDCwillconvertto12VACbypushpullandstepuptransformerwillchangethevalueof12VACto240VAC..thati'mright?

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WsiKatinzy October26,2013at11:04AM

ThatWasaveryGreatCircuit,Imadeit,,ItwasAwesome.butIhavealilproblem.wereducedtheFrequencyofoutputto350Hz,touseatransformerofironcore,EI6630theproblemisthattheoutputisnotstableafterawhileofusage.antherproblemisthatwhenwechangethevalueoftheload,thevoltageisdroppedfrom36to20VDCat600mAoutputis36VDC,if1.2A,out30V,andif1.8A20VDC.wechangedtheCTvalue(Pin5andground)from1u,to530nF.andweuseMOSFETSSF7509asHowtosolvetheproblem,.

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Anonymous November13,2013at10:50PM

HelloTahmid,I am sorry if the following question seems to be redundant but I have always been confused with the difference between Transformerfrequency, switching frequency and oscillator frequency. I know that the Oscillator Frequency(Fosc) is the Frequency set by the Resistor

CapacitorvaluesoftheSG3525AICandalso,thatthePowertransistorSwitchingfrequencyishalfoftheFoscbutwhenCalculatingNumberofPrimaryTurnandPowerHandlingcapacityoftheHFtransformerIamconfusewhichfrequencytouse(DoIuseFoscorFosc/2?)

Please,yourreplywillbegreatlyappreciated.

Regards

Faruq(Nigeria)

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AbdullrahmanAlshamma'a November25,2013at8:27AM

dearTahmidIsitnecessarytoconnecttheICtothetransistortocheckitsperformance?Weappliedavoltagebetween15Vtopin1andpinconnectedtopin16via1kohmresistorbuterroramplifieroutputatpin9itsnotcorrectitsonlyfive.why?

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December1,2013at11:47AM

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SomsakElect December1,2013at11:50AM

HelloTahmid,Iamsorry.Idon'tknowaboutcompensationpins.Canyouexplainaboutit?

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Anonymous December5,2013at3:56PM

HelloTahmidReally like your tutorials on the electronics.... I have read a fewof themnowand used some the circuits, ie: TLP250, high sideMOSFETswitching....Ihaveaquestionforyou:Iamdesigningavariableoutputvoltage(5002000VDC)pushpullconverter/inverterusingthesameSG3525Achip.

Basically, Iwillneed the5002000vdcvoltage range tobeconstantlyadjustable,butonlyneed1520ma.current.This is tobeusedas thepowersupplyforaDonSmith/Tangdevice.Icansendyoumoreinformationifyoulike.....OK,IunderstandthattheOutputvoltagecanbevariedbyusingapotentiometerfromPIN#1toVoltagedividerfromOutputfeedback>GroundcrossconnectedtoPIN#9thruappropriateresister.My question pertains to the calculations for the transformer I can't seem to find information on the construction/calculations for a variableoutputvoltagetransformertousewiththeSG2525Apushpullcircuit.WhatdoyourecommendIdotowindsuchavariablevoltagetransformer?Iwouldgreatlyappreciateanyhintsoradviceyoucangivemepertainingtodevelopingthiscircuit.I have some photos of a completed variable (5002000vdc) pushpull circuit, but they do not show underneath side of the circuit board ordiscusstheprincipalsinvolvedwiththecalculationforthetransformer.Thanksinadvancefortakingthetimetoreadthis...Haveagreatday1mjd

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Anonymous December15,2013at6:16AM

thankstahmid.thisisreallyusefulhafiz,Malaysia

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Anonymous December16,2013at2:44PM

hitahmidiamveryimpresswithurFERRITETRANSFORMERCALCULATIONbutialwaysdreamofdesigninginverterwithchoppertransformersoplzcanuhelpmewithdcircuitdiagramusingsg3525whichiwilluseddferritetransformerwithplzcomment

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Tahmid's Blog_ Using the SG3525 PWM Controller - Explanation and Example_ Circuit Diagram _ Schematic of Push-Pull Converter