圆顶灯调光器电路与LED或闪光灯电路
圆顶灯调光器电路与LED或闪光灯电路
圆顶灯调光器电路--DomeLampDimmerTherearetimeswhenalittlelightinsidethecarwouldgreatlyassistoneofthepassengersbutthedomelightistoobrightforsafedriving.Thedimmercircuitinfig.1maybeaddedtoanexistingdomelightorincludedwithanewpassengerspotlamp.Theupperop-ampgeneratesa700Hzsawtoothwaveformwhichiscomparedtoasetpointvoltagebythelowerop-amp.Whenthesawtoothvoltageisabovethesetpoint,thetransistorsturnonsupplyingcurrenttothebulb.Thesettingofthepotentiometerdeterminesthewidthofthepulsessenttothelampandthereforetheaveragevoltage.Thelampisdimwhenthepotentiometerissetnearthehighervoltage.SincetheTIP32switchesonandoffinsteadofsimplydroppingthevoltagelikeapowerrheostat,thepoweritdissipatesremainslowandaheatsinkisnotnecessary.
ClickOnimagefortheFullManyautosrunpowertolampswithonlyonewireusingthecarbodyforthereturncurrentpathsothedimmermustinterruptthepositiveleadasshown.SimplycutthewireleadingtothelampandconnectthelampendtothecollectoroftheTIP32andconnectthebatteryendtothecircuitpowerinput.Runanadditionalgroundwiretotheautochassisfromthecircuit.Thisgroundwirewillnotcarrymuchcurrentandmaybeasmallergauge.LED或闪光灯电路--LEDorLampFlasherMinimumpartscountingDesignedfor3Vbatteryoperation
Parts:R1_______33K1/4WResistorR2,R3____47R1/4WResistorsC1_______10F25VElectrolyticCapacitorD1,(D2)__LED(s)(Anytypeandcolor)Q1_____BC56045V100mAPNPTransistorQ2_____BC33745V800mANPNTransistorNotes:Powersupplycanvaryfrom2to4.5V.AddD2toobtaintwoLEDalternateblinking.D1'son-timeisshorterthanoff-time.TheoppositeregardingD2.YoucanalsouseD2only,shortingD1.Don'tchangeresistors'values.FlashingfrequencycanbevariedchangingC1valuefrom2.2Fto100Fandhigher.Thiscircuitisveryefficientwhendrivinga3.2Vlamp.InthiscaseomittheLEDsandR3,connectingthelampatQ2'scollectorandtopositivesupply,furtherreducingpartscounting.
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