Question

For a type E chopper, when CH2 is first on and then switched off then the

(a) power flows from source to load

(b) power flows from load to source

(c) load is short circuited

(d) none of the mentioned

I have been asked this question by my school teacher while I was bunking the class.

Question is taken from Type E Choppers-1 in chapter Choppers of Power Electronics

Answer 1

The correct choice is (b) power flows from load to source

Easiest explanation: With CH2 on, negative current flows through L, CH2, CH3 and CH4. When CH2 is turned off, current is fed back to the diodes by D1 and D4. Load voltage is positive and current is negative, hence second current operation is operated.