Step Down Chopper with R-L-E Load : Continues Current Conduction Mode

Step Down Chopper with R-L-E Load : Continues Current Conduction Mode Step Down Chopper(Buck Converter): It is a static device that steps down/lowers its DC input voltage Average output voltage is less than fixed DC input source voltage. It uses power devices such power BJT, Power MOSFET,GTO and Force commutated SCR as switch. E.m.f. E is battery or back e.me.f. of dc motor Operation of Step Down Chopper with R-L Load : Continues current conduction ⇒ when inductance is high Discontinues current conduction ⇒ when inductance is low 1. Dis-Continues current conduction It has two modes of operation : Mode I ⇒ During interval 0 to DT Mode II ⇒ During interval DT to T Operation of Step Down Chopper with R-L Load : Continues current conduction Mode 1(Energy storing mode) : During interval 0 to DT When SW= ON ⇒ SW act as short circuit ⇒ IL starts flowing ⇒ VL=VS Due to inductive Load the load starts storing the energy and load current increased from minimum to maximum. Mode 2(Free-wheeling mode) : During interval DT to T When SW= OFF ⇒ SW act as open circuit ⇒ IL = continuous to flow due to inductor ⇒ VL= 0 Due to self induced emf free wheeling diode is forward biased. Free wheeling takes place at t = DT and energy stored is dissipated and IL reduces from ILmax to ILmin Limitation of Step down Chopper with R-L-E load in Continues current conduction For constant Chopping period T = TON + TOFF If TON is decreases then TOFF will increase and if TOFF increases the Load current in Mode II operation will decrease to zero. #StepDownChopperwithRLELoad #OutputWaveformsofStepdownchopperwithRLELoad #StepDownChopperinCurrentCoductionMode #OperatingModesofStepdownChopperwithRLELoad