Semi-conductor direct current control circuits

Claim 1

SEMI-CONDUCTOR DIRECT CURRENT CONTROL CIRCUIT COMPRISING IN COMBINATION A SWITCHABLE RECTIFIER, SAID SWITCHABLE RECTIFIER HAVING AN ANODE, A CATHODE AND A GATE, AND BEING SWITCHED ON BY A POSITIVE PULSE APPLIED BETWEEN ITS GATE AND CATHODE, AND BEING SWITCHED OFF BY A NEGATIVE PULSE APPLIED BETWEEN ITS GATE AND CATHODE, A LOAD IN THE ANODE-CATHODE CIRCUIT OF THE SWITCHABLE RECTIFIER, A FIRING CIRCUIT FOR THE SWITCHABLE RECTIFIER, THE FIRING CIRCUIT INCLUDING A CAPACITOR ONE SIDE OF WHICH IS CONNECTED TO THE CATHODE OF THE SWITCHABLE RECTIFIER AND THE OTHER SIDE OF WHICH IS CONNECTED TO THE GATE OF THE SWITCHABLE RECTIFIER THROUGH PARALLEL CIRCUITS CONTAINING RESPECTIVELY A PAIR OF OPPOSITELY CONNECTED FOUR-LAYER DIODES, EACH FOUR-LAYER DIODE BREAKING DOWN WHEN THE VOLTAGE ACROSS IT EXCEEDS A PREDETERMINED VALUE, AND THEN CONDUCTING UNTIL THE VOLTAGE ACROSS IT FALLS SUBSTANTIALLY TO ZERO, MEANS FOR CHARGING THE CAPACITOR TO ONE POLARITY, MEANS FOR BREAKING DOWN ONE OF THE FOUR-LAYER DIODES IN THE FORWARD SENSE WHEN THE CAPACITOR IS CHARGED TO SAID ONE POLARITY, AT WHICH POINT THE CAPACITOR DISCHARGES THROUGH SAID ONE FOURLAYER DIODE AND THE GATE AND CATHODE OF THE SWITCHABLE RECTIFIER TO SWITCH THE LATTER ON, MEANS FOR CHARGING THE CAPACITOR TO THE OPPOSITE POLARITY, MEANS FOR BREAKING DOWN THE OTHER FOUR-LAYER DIODE IN THE FORWARD SENSE WHEN THE CAPACITOR IS CHARGED TO SAID OPPOSITE POLARITY, AT WHICH POINT THE CAPACITOR DISCHARGES THROUGH SAID OTHER FOUR-LAYER DIODE AND THE GATE AND CATHODE OF THE SWITCH ABLE RECTIFIER TO SWITCH THE LATTER OFF, AND MEANS FOR PREVENTING BREAKDOWN OF EITHER FOUR-LAYER DIODE IN THE REVERSE DIRECTION BY THE VOLTAGE MAINTAINED ACROSS IT BY THE CAPACITOR.