Question

Find the triggering frequency when the average gate power dissipation = 0.3 W and the peak gate drive power is 5 Watts. The gate source has a pulse width of 20 μsec duration.

(a) 3 kHz

(b) 0.3 kHz

(c) 30 kHz

(d) 0.03 mHz

This question was posed to me by my college director while I was bunking the class.

Enquiry is from Firing Circuits-1 topic in section Other Circuits of Power Electronics

Answer 1

Right option is (a) 3 kHz

The explanation: (Pgm) = (Pgav)/Duty Cycle

Duty Cycle = f x T = (Pgav)/(Pgm)

Duty Cycle = 0.3/5

T = 20 μsec.

0.3/5 = f x T

f = (0.3)/(5 x 20 x 10^-6) = 3000 Hz.