Communication Systems - Engineering

Q1:

A horizontal output stage is cutoff for retrace and 40% of trace. If time for each horizontal line is 64 μs and retrace time is 12 μs, the transistor is conducting for about

A 64 μs

B 6.4 μs

C 31 μs

D 3.1 μs

ANS:C - 31 μs

Total time for each horizontal line = . Time for trace = 64 - 12 = 52 μs. Time for which transistor is not conducting = 12 + 0.4 x 52 = 32.8 ms. Time for which transistor is conducting = 64 - 32.8 = 31 μs.