圓頂燈調光器電路與LED或閃光燈電路

圓頂燈調光器電路與LED或閃光燈電路
圓頂燈調光器電路--DomeLampDimmerTherearetimeswhenalittlelightinsidethecarwouldgreatlyassistoneofthepassengersbutthedomelightistoobrightforsafedriving.Thedimmercircuitinfig.1maybeaddedtoanexistingdomelightorincludedwithanewpassengerspotlamp.Theupperop-ampgeneratesa700Hzsawtoothwaveformwhichiscomparedtoasetpointvoltagebythelowerop-amp.Whenthesawtoothvoltageisabovethesetpoint,thetransistorsturnonsupplyingcurrenttothebulb.Thesettingofthepotentiometerdeterminesthewidthofthepulsessenttothelampandthereforetheaveragevoltage.Thelampisdimwhenthepotentiometerissetnearthehighervoltage.SincetheTIP32switchesonandoffinsteadofsimplydroppingthevoltagelikeapowerrheostat,thepoweritdissipatesremainslowandaheatsinkisnotnecessary.
ClickOnimagefortheFullManyautosrunpowertolampswithonlyonewireusingthecarbodyforthereturncurrentpathsothedimmermustinterruptthepositiveleadasshown.SimplycutthewireleadingtothelampandconnectthelampendtothecollectoroftheTIP32andconnectthebatteryendtothecircuitpowerinput.Runanadditionalgroundwiretotheautochassisfromthecircuit.Thisgroundwirewillnotcarrymuchcurrentandmaybeasmallergauge.LED或閃光燈電路--LEDorLampFlasherMinimumpartscountingDesignedfor3Vbatteryoperation
Parts:R1_______33K1/4WResistorR2,R3____47R1/4WResistorsC1_______10΅F25VElectrolyticCapacitorD1,(D2)__LED(s)(Anytypeandcolor)Q1_____BC56045V100mAPNPTransistorQ2_____BC33745V800mANPNTransistorNotes:Powersupplycanvaryfrom2to4.5V.AddD2toobtaintwoLEDalternateblinking.D1'son-timeisshorterthanoff-time.TheoppositeregardingD2.YoucanalsouseD2only,shortingD1.Don'tchangeresistors'values.FlashingfrequencycanbevariedchangingC1valuefrom2.2΅Fto100΅Fandhigher.Thiscircuitisveryefficientwhendrivinga3.2Vlamp.InthiscaseomittheLEDsandR3,connectingthelampatQ2'scollectorandtopositivesupply,furtherreducingpartscounting.