Question

A step down chopper feeding an inductive load and current is ripple free in the output circuit. If duty cycle is 0.75, then the ratio of rms current through freewheeling diode to rms current through switch is_______

Answer 1

Let, $I_0$= ripple free load current

Rms current through free wheeling diode=$I_0\sqrt{1-D}$

Rms current through switch
=$I_0\sqrt{D}$

Required Ratio
= $\frac{I_0\sqrt{1-D}}{I_0\sqrt{D}}=\frac{\sqrt{1-0.75}}{\sqrt{0.75}}=0.57$