A step down chopper operates from a dc voltage source Vs, and feeds a dc motor armature with a back emf Eb.
From oscilloscope traces, it is found that the current increases for time tr, falls to zero over time t1, and remains zero for time t0, in every chopping cycle.
Then the average dc voltage across the freewheeling diode is
A. Vstr / (tr+tf+t0)
B. (Vstr + Eb * tf) / (tr+tf+t0)
C. (Vstr + Eb * t0) / (tr+tf+t0)
D. (Vstr + Eb * [t0 + tf]) / (tr+tf+t0)
Show Answer
Answer: C
Share your understanding of this question with the correct explanation.