Why should I specify a 'pulse width' when firing a thyristor rectifier/inverter?
The pulse width refers to the duration of the gate firing pulse. The firing angle is determined by the delay time between the zero crossing point and initiation of the gate pulse. The thyristor does not turn on instantaneously, it requires some time, perhaps 1 to 50 microseconds. The minimum required pulse width would be determined from the thyristor specification. The minimum required gate pulse time may vary with the current that the gate drive circuit supplies.