Current limit circuit

Claim 1

A SYSTEM FOR LIMITING THE CURRENT OF A D.C. MOTOR COMPRISING: POWER CIRCUIT MEANS FOR CONTROLLING THE ARMATURE CURRENT FOR THE MOTOR; A THREE-PHASE MAGNETIC AMPLIFIER COMPRISING THREE SATURABLE MAGNETIC CORES, THREE LOAD WINDINGS IN INDUCTIVE RELATIONSHIP RESPECTIVELY TO SAID CORES, AND A CONTROL WIDING IN INDUCTIVE RELATIONSHIP TO SAID CORES; AN ARMATURE SHUNT CONNECTED TO THE ARMATURE OF THE MOTOR; MEANS CONNECTING SAID CONTROL WINDING TO SAID ARMATURE SHUNT TO APPLY TO SAID CONTROL WINDING A D.C. CONTROL SIGNAL PROPORTIONAL IN MAGNITUDE TO THE CURRENT TO THE MOTOR ARMATURE AND WHICH INDUCES MAGNETIC FLUX IN ONE DIRECTION IN SAID CORES; AN A.C. POWER SUPPLY INCLUDING A THREE-PHASE TRANSFORMER HAVING A NEUTRAL POINT; MEANS FOR CONNECTING EACH PHASE OF THE TRANSFORMER TO ONE SIDE OF A CORRESPONDING LOAD WINDING FOR ENERGIZING THE LATTER TO INDUCE FLUX IN THE CORRESPONDING CORE WHICH IS IN SAID ONE DIRECTION IN ONEHALF OF THE A.C. POWER SUPPLY AND WHICH IS IN THE OPPOSITE DIRECTION IN THE OPPOSITE HALF-CYCLE OF THE A.C. POWER SUPPLY; A FIRST SET OF THREE RECTIFIERS, EACH HAVING ITS TERMINAL OF ONE POLARITY CONNECTED TO THE OPPOSITE SIDE OF A RESPECTIVE LOAD WINDING AND EACH HAVING ITS OPPOSITE POLARITY TERMINAL CONNECTED DIRECTLY TO THE OPPOSITE POLARITY TERMINAL OF EACH OTHER RECTIFIER IN SAID SET, EACH SAID RECTIFIER BEING OPERATIVE TO PASS SUBSTANTIAL CURRENT ONLY OF A POLARITY CORRESPONDING TO SAID ONE DIRECTION OF FLUX IN THE RESPECTIVE CORE; A SECOND SET OF RECTIFIERS, EACH HAVING ITS TERMINAL OF SAID OPPOSITE POLARITY CONNECTED TO SAID OPPOSITE SIDE OF A RESPECTIVE LOAD WINDING AND EACH HAVING ITS TERMINAL TO SAID ONE POLARITY CONNECTED DIRECTLY TO SAID ONE POLARITY TERMINAL OF EACH OTHER RECTIFIER IN SAID SECOND SET, EACH OF SAID RECTIFIER IN THE SECOND SET BEING OPERATIVE TO PASS SUBSTANTIAL CURRENT ONLY OF A POLARITY CORRESPONDING TO SAID OPPOSITE DIRECTION OF FLUX IN THE RESPECTIVE CORE; VARIBLE RESISTANCE MEANS CONNECTED BETWEEN SAID ONE POLARITY TERMINALS OF THE RECTIFIERS IN THE SECOND SET AND SAID NEUTRAL POINT OF THE TRANSFORMER TO SELECTIVELY REDUCE THE MAGNITUDE OF SAID LAST-MENTIONED CURRENT; BLOCKING MEANS CONNECTED TO SAID OPPOSITE POLARITY TERMINALS OF THE RECTIFIERS IN THE FIRST SET AND OPERATIVE PASS CURRENT THEREFROM ONLY WHEN SAID CURRENT EXCEEDS A PREDETERMINED MAGNITUDE; AND A FEEDBACK CIRCUIT CONNECTED BETWEEN SAID MOTOR ARMATURE AND SAID POWER CIRCUIT MEANS AND OPERATIVE, IN RESPONSE TO OUTPUT CURRENT FROM THE MAGNETIC AMPLIFIER PASSED BY SAID BLOCKING MEANS, TO LIMIT THE MOTOR ARMATURE CURRENT PRODUCED BY SAID POWER CIRCUIT MEANS.

Claim 2

A SYSTEM FOR LIMITING THE CURRENT OF A D.C. MOTOR COMPRISING: POWER CIRCUIT MEANS FOR CONTROLLING THE ARMATURE CURRENT FOR THE MOTOR; A THREE-PHASE MAGNETIC AMPLIFIER COMPRISING THREE SATURABLE MAGNETIC CORES, THREE LOAD WINDINGS IN INDUCTIVE RELATIONSHIP RESPECTIVELY TO SAID CORES, AND A CONTROL WIDING IN INDUCTIVE RELATIONSHIP TO SAID CORES; AN ARMATURE SHUNT CONNECTED TO THE ARMATURE OF THE MOTOR; MEANS CONNECTING SAID CONTROL WINDING TO SAID ARMATURE SHUNT TO APPLY TO SAID CONTROL WINDING A D.C. CONTROL SIGNAL PROPORTIONAL IN MAGNITUDE TO THE CURRENT TO THE MOTOR ARMATURE AND WHICH INDUCES MAGNETIC FLUX IN ONE DIRECTION IN SAID CORES; AN A.C. POWER SUPPLY INCLUDING A THREE-PHASE TRANSFORMER HAVING A NEUTRAL POINT; MEANS FOR CONNECTING EACH PHASE OF THE TRANSFORMER TO ONE SIDE OF A CORRESPONDING LOAD WINDING FOR ENERGIZING THE LATTER TO INDUCE FLUX IN THE CORRESPONDING CORE WHICH IS IN SAID ONE DIRECTION IN ONEHALF OF THE A.C. POWER SUPPLY AND WHICH IS IN THE OPPOSITE DIRECTION IN THE OPPOSITE HALF-CYCLE OF THE A.C. POWER SUPPLY; A FIRST SET OF THREE RECTIFIERS, EACH HAVING ITS TERMINAL OF ONE POLARITY CONNECTED TO THE OPPOSITE SIDE OF A RESPECTIVE LOAD WINDING AND EACH HAVING ITS OPPOSITE POLARITY TERMINAL CONNECTED DIRECTLY TO THE OPPOSITE POLARITY TERMINAL OF EACH OTHER RECTIFIER IN SAID SET, EACH SAID RECTIFIER BEING OPERATIVE TO PASS SUBSTANTIAL CURRENT ONLY OF A POLARITY CORRESPONDING TO SAID ONE DIRECTION OF FLUX IN THE RESPECTIVE CORE; A SECOND SET OF RECTIFIERS, EACH HAVING ITS TERMINAL OF SAID OPPOSITE POLARITY CONNECTED TO SAID OPPOSITE SIDE OF A RESPECTIVE LOAD WINDING AND EACH HAVING ITS TERMINAL TO SAID ONE POLARITY CONNECTED DIRECTLY TO SAID ONE POLARITY TERMINAL OF EACH OTHER RECTIFIER IN SAID SECOND SET, EACH OF SAID RECTIFIER IN THE SECOND SET BEING OPERATIVE TO PASS SUBSTANTIAL CURRENT ONLY OF A POLARITY CORRESPONDING TO SAID OPPOSITE DIRECTION OF FLUX IN THE RESPECTIVE CORE; VARIBLE RESISTANCE MEANS CONNECTED BETWEEN SAID ONE POLARITY TERMINALS OF THE RECTIFIERS IN THE SECOND SET AND SAID NEUTRAL POINT OF THE TRANSFORMER TO SELECTIVELY REDUCE THE MAGNITUDE OF SAID LAST-MENTIONED CURRENT; BLOCKING MEANS CONNECTED TO SAID OPPOSITE POLARITY TERMINALS OF THE RECTIFIERS IN THE FIRST SET AND OPERATIVE PASS CURRENT THEREFROM ONLY WHEN SAID CURRENT EXCEEDS A PREDETERMINED MAGNITUDE; AND A FEEDBACK CIRCUIT CONNECTED BETWEEN SAID MOTOR ARMATURE AND SAID POWER CIRCUIT MEANS AND OPERATIVE, IN RESPONSE TO OUTPUT CURRENT FROM THE MAGNETIC AMPLIFIER PASSED BY SAID BLOCKING MEANS, TO LIMIT THE MOTOR ARMATURE CURRENT PRODUCED BY SAID POWER CIRCUIT MEANS.