Firing circuit for a controlled rectifier

Claim 1

A CONTROLLED RECTIFIER MEANS AND A FIRING CIRCUIT THEREFOR COMPRISING A CONTROLLED RECTIFIER MEANS HAVING GATE TERMINAL MEANS AND CONNECTED BETWEEN A SOURCE OF ALTERNATING VOLTAGE OF RELATIVELY LOW FREQUENCY AND A LOAD, A SOURCE OF PERIODIC VOLTAGE OF SQUARE-WAVE FORM AND OF THE SAME FRQUENCY AND AJUSTABLY PHASE-POSITIONED WITH RESPECT TO SAID SOURCE OF ALTERNATING VOLTAGE, A ONESHOT MULTIVIBRATOR HAVING A PAIR OF INPUTS, A PULSE FORMER RESPONSIVE TO SAID PERIODIC VOLTAGE TO PRODUCE PULSES OF ALTERNATE POLARITY AND OF THE AME FREQUENCY AS SAID SOURCE, MEANS IMPRESSING SAID PULSE OF ONE POLARITY ON ONE OF SAID INPUTS OF SAID MULTIVIBRATOR AND SAID PULSES OF THE OPPOSITE POLARITY ON THE OTHER OF SAID INPUTS OF SAID MULTIVIBRATOR, SAID MULTIVIBRATOR INCLUDING MEANS TO PROVIDE A UNIDIRECTIONAL PULSE UPON RECEPTION OF EACH INPUT PULSE, SAID UNIDIRECTIONAL PULSES BEING OF LONGER DURATION THAN SAID INPUT PULSES BUT OF SHORTER DURATION THAN ONE-HALF CYCLE OF SAID SOURCE OF ALTERNATING VOLTAGE, AN OSCILLATOR RESPONSIVE TO SAID UNIDIRECTIONAL PULSES TO PROVIDE, ONLY DURING EACH UNIDIRECTIONAL PULSE, A TRAIN OF A PREDETERMINED NUMBER OF PULSES OF RELATIVELY HIGH FREQUENCY EACH CAPABLE OF FIRING SAID CONTROLLED RECTIFIER MEANS, AND MEANS FOR IMPRESSING EACH PULSE OF SAID TRAIN OF PULSES AT SAID GATE TERMINAL MEANS OF SAID CONTROLLED RECTIFIER MEANS.