Electronic control of motors

Claim 1

IN COMBINATION WITH A THREE PHASE POWER SUPPLY MAINS AND AN ASYNCHRONOUS MOTOR INCLUDING A THREE-PHASE STATOR AND A ROTOR HAVING SLIP RINGS CONNECTED THERETO, A CONTROL CIRCUIT FOR CONTROLLING SAID MOTOR IN SUCH A MANNER AS TO CAUSE IT TO BE ROTATED IN EITHER DIRECTION OVER A WIDE RANGE OF SPEEDS AND TO BE BRAKED BY A DIRECT CURRENT FOR EITHER DIRECTION OF ROTATION, SAID CIRCUIT COMPRISING: (A) STATOR SIDE CONTROL MEANS CONSISTING OF A FIRST PAIR OF THYRISTORS CONNECTED IN PARALLEL OPPOSITION BETWEEN A FIRST PHASE OF SAID MAINS AND A FIRST PHASE OF SAID STATOR, A FIRST INDIVIDUAL THYRISTOR CONNECTED BETWEEN A SECOND PHASE OF SAID MAINS AND SAID FIRST PHASE OF SAID STATOR IN SUCH A MANNER AS TO CONDUCT IN A FORWARD DIRECTION TOWARD SAID STATOR, A SECOND PAIR OF THYRISTORS CONNECTED IN PARALLEL OPPOSITION BETWEEN A THIRD PHASE OF SAID MAINS AND SAID FIRST PHASE OF SAID STATOR, A THIRD PAIR OF THYRISTORS CONNECTED IN PARALLEL OPPOSITION BETWEEN SAID SECOND MAINS PHASE AND A SECOND PHASE OF SAID STATOR, A FOURTH PAIR OF THYRISTORS CONNECTED IN PARALLEL OPPOSITION BETWEEN SAID SECOND MAINS PHASE AND A THIRD PHASE OF SAID STATOR, A SECOND INDIVIDUAL THYRISTOR CONNECTED BETWEEN SAID SECOND MAINS PHASE AND SAID THIRD STATOR PHASE IN SUCH A MANNER AS TO CONDUCT IN A FORWARD DIRECTION AWAY FROM SAID STATOR, AND A FIFTH PAIR OF THYRISTORS CONNECTED IN PARALLEL OPPOSITION BETWEEN SAID THIRD MAINS PHASE AND SAID THIRD STATOR PHASE;