Question

A single phase voltage controller has input of 230 V and a load of 15 Ω resistive. For 6 cycles on and 4 cycles off, determine the average value of SCR current.

(a) 21.68 A

(b) 200 mA

(c) 4.14 A

(d) 2.07 A

This question was posed to me during an interview.

The origin of the question is AC Voltage Controllers-3 topic in chapter Voltage Controllers of Power Electronics

Answer 1

Right choice is (c) 4.14 A

Easy explanation: Peak current Im = (230 x √2)/15 = 21.681 A

k = (6/6+4) = 6/10 = 0.6

Avg current = (k Im)/π = 4.14 A.