LED或灯序电路

LED或灯序电路
LED或灯序电路--LEDsorLampsSequencer
Parts:R1______________1K51/4WResistorR2____________680R1/4WResistor(Optional,seetext)C1_____________47F25VElectrolyticCapacitorD1_____________LEDanytypeQ1___________BC33745V800mANPNTransistorP1_____________SPSTPushbuttonLP1____________FilamentLamp12or24V(Seetext)Comments:ThepurposeofthiscircuitwastocreatearinginwhichLEDsorLampsilluminatesequentially.Itsmainfeatureisahighversatility:youcanbuildaloopcontaininganynumberofLEDsorLamps,aseachilluminatingdevicehasitsownsmallcircuit.Thediagramsshowthree-stagecircuitsforsimplicity:youcanaddanunlimitednumberofstages(shownindashedboxes),providedthelaststageoutputwasreturnedtothefirststageinput,asshown.P1pushbuttonpurposeistoallowasurestartofthesequenceatpower-onbut,whenahighnumberofstagesisused,italsoallowsilluminationofmorethanoneLEDorLampatatime,e.g.onedeviceilluminatedandthreeoutandsoon.Afterpower-on,P1shouldbeheldcloseduntilonlytheLEDorLamprelatedtothemoduletowhichthepushbuttonisconnectedremainssteadyilluminated.WhenP1isreleasedthesequencerstarts:ifP1ispushedbrieflyafterthesequenceisstarted,severaltypesofsequencecanbeobtained,dependingfromthetotalnumberofstages.Notes:IfoneLEDpermoduleisused,voltagesupplycanrangefrom6to15V.YoucanuseseveralLEDspermodule.Theymustbewiredinseriesandsupplyvoltagemustberelatedtotheirnumber.Using24Vsupply(themaximumpermittedvoltage),about10LEDswiredinseriescanbeconnectedtoeachmodule,about7at15Vandnomorethan5at12V.TherightnumberofLEDscanvary,asitisdependingbytheircolorandbrightnessrequired.Usinglamps,voltagesupplycanrangefrom9to24V.Obviously,lampvoltagemustbethesameofsupplyvoltage.Inanycase,lampsmayalsobewiredinseries,e.g.four6Vlampswiredinseriescanbeconnectedtoeachmoduleandpoweredby24Vsupply.Ifyouintendtouselampsdrawingmorethan400mAcurrent,BC337transistorsshouldbesubstitutedbyDarlingtontypeslikeBD677,BD679,BD681,2N6037,2N6038,2N6039etc.AsDarlingtontransistorusuallyhaveabuilt-inBase-Emitterresistor,R1maybeomitted,furtherreducingpartscounting.SequencerspeedcanbevariedchangingC1value.Asimilardesignappearedinprintaboutfortyyearsago.Itusedgermaniumtransistorsandlowvoltagelamps.IthinktheuseofLEDs,silicontransistors,Darlingtontransistorsand24Vsupplyaninterestingimprovement.