Test circuit for evaluating turn-off controlled rectifiers under dynamic conditions

Claim 1

A TURN-OFF CONTROLLED RECTIFIER ANALYZER COMPRISING: (A) A CIRCUIT MEANS FOR CONNECTION TO A DIRECT CURRENT SOURCE AND TO THE ANODE AND COTHODE OF A TURN-OFF CONTROLLED RECTIFIER TO PROVIDE RATED FORWARD VOLTAGE DURING THE OFF-STATE AND RATED FORWARD CURRENT DURING THE ON STATE OF THE TURN-OFF CONTROLLED RECTIFIER AND FOR PROVIDING A SUBSTANTIAL READILY MEASURABLE VOLTAGE DROP PROPORTIONAL TO THE FORWARD LEAKAGE CURRENT, (B) A PAIR OF DIODES, (C) THE ANODE OF ONE DIODE AND THE CATHODE OF THE OTHER DIODE CONNECTED IN COMMON FOR CONNECTION TO ONE TERMINAL OF A SOURCE ALTERNATELY POSITIVE AND NEGATIVE PERIODIC PULSES, (D) TWO POTENTIOMETERS, (E) ONE END OF THE RESISTANCES OF THE POTENTIOMETERS CONNECTED TO THE OTHER ENDS OF THE DIODES RESPECTIVELY, (F) THE RESISTANCES OF THE POTENTIOMETERS BEING JOINED AT THEIR FREE ENDS FOR CONNECTION TO THE OTHER TERMINAL OF SAID SOURCE AND TO THE CATHODE OF THE TURN-OFF CONTROLLED RECTIFIER UNDER TEST, (G) A METERING RESISTOR CONNECTED AT ONE END TO THE TAPS OF BOTH POTENTIOMETERS IN COMMON AND AT THE OTHER END TO THE GATE TERMINAL OF THE TURN-OFF CONTROLLED RECTIFIER.