Function of Freewheeling Diode (FWD): a) Freewheeling diode is used across inductive loads such as coils, dc motor armature etc. to prevent voltage spikes across these loads when the switching device is turned off. b) It is used to bypass the stored energy in inductive elements when the switching device is turned off. c) In absence of FWD, the stored energy in inductance will maintain forward current through the power semiconductor device and prevent it from being turned off. d) When the power semiconductor device in series with load is turned off, the free-wheeling diode is forward biased and the current in load is bypassed through FWD. Since load current is shifted from switching device, it is turned off easily and regain its blocking ability.