Rectifier system for controlling the magnitude and polarity of direct voltage by means of two rectifier bridge networks

Claim 1

A RECTIFIER SYSTEM FOR PROVIDING A CONTROLLABLE DIRECT VOLTAGE OF REVERSIBLE POLARITY, COMPRISING ALTERNATING-CURRENT FEEDERS, TWO DIRECT-CURRENT LOAD BUSES, TWO RECTIFIER BRIDGE NETWORKS HAVING RESPECTIVE INPUT POINTS CONNECTED TO SAID FEEDERS AND EACH HAVING TWO OUTPUT POINTS CONNECTED TO SAID RESPECTIVE LOAD BUSES, EACH OF SAID NETWORKS HAVING THYRISTORS POLED IN OPPOSED RELATION TO THOSE OF THE OTHER NETWORK FOR REVERSING THE DIRECT-VOLTAGE POLARITY BY BLOCKING THE THYRISTORS IN A SELECTED ONE OF SAID NETWORKS, CONTROL MEANS CONNECTED TO SAID THYRISTORS FOR SELECTIVELY BLOCKING THE THYRISTORS OF ONE NETWORK AND PHASE CONTROLLING THE THYRISTORS OF THE OTHER NETWORK TO VARY THE RECTIFIED VOLTAGE, FOUR BLOCKING DIODES SERIALLY INTERPOSED BETWEEN SAID RESPECTIVE OUTPUT POINTS AND SAID LOAD BUSES, EACH OF SAID DIODES HAVING THE SAME POLING AS THE THYRISTORS OF THE NETWORK TO WHOSE OUTPUT POINT EACH DIODE IS ELECTRICALLY ADJACENT, IMPEDANCE SHUNTS CONNECTED PARALLEL TO SAID RESPECTIVE THYRISTORS, EACH OF SAID SHUNTS COMPRISING A CAPACITOR.