Numerical - Average dc output voltage of a chopper with ON time of 20ms and OFF time of 15 ms

What will be the average dc output voltage of a chopper which is supplied by 500 V dc with ON time of 20ms and OFF time of 15 ms ?

Options:

a. 150 V
b. 230 V
c. 285 V
d. 325 V

Correct Answer: c. 285 V

Explanation:

According to given data,

T_ON = 20 ms = 20 x 10 ^-3 s

T_OFF = 15 ms = 15 x 10 ^-3 s

T = T_ON + T_OFF

T = (20 x 10 ^-3 + 15 x 10 ^-3 ) = 35 x 10^-3 s

Therefore, duty cycle of the chopper is given by,

T = T_ON / T = 20 x 10 ^-3 / 35 x 10^-3 = 0.57

Thus, average dc output voltage of chopper can be evaluated by,

V_L = V_dc x duty cycle = 500 x 0.57 = 285 V