3 phase AC Voltage controller question
The A to neutral voltage is zero when neither T1 nor T4 is conducting. When T2 &amp; T3 or T5 and T6 are conducting, neither T1 nor T4 is conducting. It might help to diagram all three of the phase voltages and all of the conduction paths. The T4, T5, T6 gate sequence repeats after the third period of conduction that is numbered in the diagrams.