Voltage regulation for a. c.-to-d. c. converters

Claim 1

A SYSTEM FOR INITATING THE CHARGING OF A CONDENSER IN AN RC TIMING CIRCUIT AT A PRECISE ANGLE THE WAVE OF A POLYPHASE VOLTAGE SOURCE, THE SYSTEM COMPRISING A POLYPHASE A.C. SOURCE AND RECTIFYING MEANS COUPLED TO SAID SOURCE AND ADAPTED TO DEVELOP AN UNDULATING RECTIFIED ALTERNATING VOLTAGE WAVE OF A CONSTANT FREQUENCY, A UNIJUNCTION TRANSISTOR COUPLED TO SAID RECTIFYING MEANS AND HAVING BASE1, BASE 2 AND EMITTER ELECTRODES, THE PEAK EMITTER VOLTAGE FOR INITIATING CURRENT IN THE EMITTER-BASE-1 CIRCUIT OF SAID TRANSISTOR BEING A FIXED FUNCTION N OF THE BASE-TO-BASE VOLTAGE, A COUPLING RESISTOR CONNECTED BETWEEN SAID BASES AND SAID RECTIFYING MEANS, A VOLTAGE CLAMP DEVICE CONNECTED TO THE BASE-1 END OF SAID RESISTOR FOR CLAMPING THE BASE-1 AT A VOLTAGE CORRESPONDING TO THE CROSSOVER VOLTAGE OF TWO ADJACENT WAVES OF SAID RECTIFIED WAVE, AN RC TIMING CIRCUIT COUPLED BETWEEN SAID EMITTER ELECTRODE AND SAID RECTIFYING MEANS AND INCLUDING A STORAGE CONDENSER AND ADJUSTABLE RESISTANCE MEANS, A SECOND VOLTAGE CLAMP DEVICE CONNECTED TO THE BASE-2 END OF SAID RESISTOR FOR CLAMPING SAID BASE-2 VOLTAGE AT SOME VOLTAGE INTERMEDIATE THE CLAMPED VOLTAGE OF SAID BASE-1 AND THE PEAK VOLTAGE OF SAID RECTIFYING MEANS SO THAT SAID UNIJUNCTION TRANSISTOR BECOMES NONCONDUCTING AND SAID CONDENSER BEGINS TO CHARGE AT THE INSTANT OF SIAD CROSSOVER.