Convertor arrangements

Claim 1

A STATIC CONVERTOR COMPRISING A THREE-PHASE ALTERNATING VOLTAGE SUPPLY SOURCE, THREE BRIDGE NETWORKS EACH NETWORK COMPRISING FIRST, SECOND, THIRD AND FOURTH INTERCONNECTED ARMS HAVING FIRST AND SECOND PAIRS OF DIAGONALLY OPPOSING CORNERS, A THYRISTOR CONNECTED IN EACH ARM, AND A CAPACITOR CONNECTED DIAGONALLY BETWEEN SAID FIRST AND SECOND, AND THIRD AND FOURTH, ARMS, TWO DIODES CONNECTED IN SERIES WITH ONE ANOTHER AND HAVING A JUNCTION TERMINAL THEREBETWEEN, MEANS CONNECTING SAID DIODES DIAGONALLY BETWEEN SAID SECOND AND THIRD, AND FOURTH AND FIRST, ARMS COMMON TO ALL THREE OF THE SAID BRIDE NETWORKS, TERMINAL MEANS BETWEEN SAID COMMON SECOND AND THIRD, AND SAID COMMON FOURTH AND FIRST, ARMS, FOR RECEIVING AN ELECTRICAL LOAD THEREBETWEEN, MEANS CONNECTING THE THREE PHASES OF SAID SUPPLY BETWEEN THE COMMON JUNCTION TERMINAL AND SAID FIRST AND SECOND ARMS IN THE THREE BRIDES, RESPECTIVELY, AND