Transistor trigger-pulse circuit

Claim 1

AN ELECTRONIC FIRING CIRCUIT SUITABLE FOR TRIGGERING A CONTROLLED RECTIFIER AND COMPRISING: (A) A TRANSISTOR HAVING A BASE, AN EMITTER AND A COLLECTOR; (B) AN ALTERNATING CURRENT SUPPLY HAVING A MAIN FREQUENCY IN THE ORDER OF 60 CYCLES PER SECOND; (C) A FIRST CIRCUIT FED BY THE ALTENATING CURRENT SUPPLY AND PRODUCING AS OUTPUT HALF-WAVE-RECTIFIED AND CLIPPED DIRECT VOLTAGE; (D) A SECOND CIRCUIT FED BY THE ALTERNATING CURRENT SUPPLY AND GENERATING A FLUCTUATING DIRECT VOLTAGE OF RAMP WAVEFORM AT THE SUPPLY FREQUENCY; (E) A THIRD CIRCUIT PRODUCING A CONTROLLABLE DIRECT CURRENT BIAS VOLTAGE DURING SUBSTANTIALLY THE WHOLE PERIOD OF EACH ALTERNATE HALF CYCLE OF THE ALTERNATING CURRENT SUPPLY; (F) A CIRCUIT FED BY SAID SECOND AND THIRD CIRCUITS AND CONNECTED BETWEEN SAID BASE AND EMITTER BY WHICH THE RAMP WAVEFORM AND THE CONTROLLABLE DIRECT CURRENT BIAS VOLTAGE ARE JOINTLY APPLIED BETWEEN THE BASE AND THE EMITTER TO RENDER THE TRANSISTOR CONDUCTIVE WHEN THE VOLTAGE OF THE RAMP WAVEFORM OVER-RIDES THE BIAS VOLTAGE; (G) ADJUSTABLE CIRCUIT MEANS FOR VARYING THE CONTROLLABLE DIRECT CURRENT BIAS VOLTAGE SO AS TO VARY THE POINT IN EACH OF THE SAID ALTERNATE HALF CYCLES AT WHICH THE TRANSISTOR WILL BECOME CONDUCTIVE; (H) AND AN ELECTRICAL NETWORK INCLUDING THE EMITTER AND THE COLLECTOR OF THE TRANSISTOR AND FORMING A BLOCKING-OSCILLATOR, SAID NETWORK BEING FED WITH THE HALF-WAVE-RECTIFIED AND CLIPPED VOLTAGE OUTPUT OF SAID FIRST CIRCUIT AND PRODUCING A TRAIN OF OUTPUT PULSES IN AN OUTPUT CIRCUIT DURING THE PART OF EACH OF THE SAID ALTERNATE HALF CYCLES WHEN THE TRANSISTOR IS CONDUCTIVE, THE PULSE REPETITION FREQUENCY BEING SEVERAL KILOCYCLES PER SECOND.