Steuervorrichtung fuer einen gesteuerten Gleichrichter

摘要

1299092 Commutating controlled rectifiers COMPAGNIE GENERALE D'ELECTRONIQUE INDUSTRIELLE LEPAUTE 17 Dec 1969 [17 Dec 1968] 61534/69 Heading H2F [Also in Division H3] In a switching circuit using a controlled rectifier 11, the rectifier 11 is turned on by the onset of each control pulse at 40 and turned off by means of a further controlled rectifier 21 responsive to the termination of the control pulse at 40 and has further means to operate the turnoff controlled rectifier 21 in the event of excess current through the main controlled rectifier 11. As described, each control pulse at 40 is shaped in a trigger circuit 43 before being fed via an AND gate 44 to a further AND gate 42 where it gates a train of 50 kHz pulses from a multivibrator 41 to a transistor 61 the output of which is coupled via transformer 31 to the gate of the main thyristor 11. The end of each pulse at 40 is differentiated at 121, 131 and passed via a OR gate 45, transistor 141 and transformer 41 to the gate of a commutating thyristor 21 which is coupled via an oscillatory circuit to turn off the main thyristor 11. The current of the main thyristor 11 is monitored at 46 and after amplification at 47, if the resulting signal is sufficiently large to break down Zener diode 22, a signal is provided by the output of transistors 231, 251 which sets a monostable circuit 151 which results in turning on the commutating thyristor 21 (and hence turning off the main thyristor 11) and inhibiting the triggering pulses to the main thyristor 11. This action continues for a period determined by monostable circuit 151. In Fig. 1 (not shown) the control signals are used to turn on a transistor which is coupled by means of a transformer to the gate of the main thyristor, the commutating thyristor being turned on by a further transistor in response to a voltage induced in a tertiary winding of the transformer. The resistor 46 is replaced by a current transformer.