Controlled rectifier reversing motor speed system

Claim 1

A VARIABLE SPEED REVERSING MOTOR SYSTEM COMPRISING: A DIRECT CURRENT SHUNT MOTOR HAVING AN ARMATURE AND A FIELD; INPUT TERMINALS FOR MAKING CONNECTIONS TO AN ALTERNATING CURRENT SOURCE OF ELECTRICAL POWER; A FIRST REC TIFYING NETWORK CONNECTED BETWEEN SAID INPUT TERMINALS AND SAID ARMATURE FOR SUPPLYING UNIDIRECTIONAL CURRENT TO SAID ARMATURE, SAID FIRST RECTIFYING NETWORK COMPRISING TWO SEMICONDUCTOR CONTROLLED RECTIFIERS CONNECTED TO CONDUCT CURRENT IN OPPOSITE DIRECTIONS, EACH CONTROLLED RECTIFIER HAVING A CATHODE AND A CONTROL ELECTRODE FOR CONTROLLING THE CONDUCTION OF SAID CONTROLLED RECTIFIER IN RESPONSE TO A SIGNAL ON ITS CONTROL ELECTRODE; A TRANSFORMER; A PAIR OF MAGNETIC AMPLIFIERS, EACH MAGNERIC AMPLIFIER INCLUDING A CONTROL WINDING AND AN OUTPUT CIRCUIT HAVING IN SERIES AN OUTPUT WINDING, A RESISTOR, A SECONDARY WINDING OF SAID TRANSFORMER AND A DIODE RECTIFIER, SAID RESISTOR BEING CONNECTED BETWEEN THE CATHODE AND THE CONTROL ELECTRODE OF ONE OF THE CONTROLLED RECTIFIERS; A CONTROL CIRCUIT INCLUDING THE CONTROL WINDINGS OF SAID MAGNETIC AMPLIFIERS AND MEANS CONNECTED IN SERIES WITH SAID CONTROL WINDINGS FOR PRODUCING AND ADJUSTABLE AND REVERSIBLE UNIDIRECTIONAL CURRENT IN SAID CONTROL WINDINGS FOR VARIABLY CONTROLLING THE OUTPUT OF ONE MAGNETIC AMPLIFIER WHILE HOLDING THE OTHER MAGNETIC AMPLIFIER AT CUT-OFF, TO RENDER ONE OR THE OTHER CONTROLLED RECTIFIER CONDUCTIVE AND THEREBY DETERMINE THE DIRECTION OF MOTOR ROTATION; MEANS FOR CONNECTING SAID TRANSFORMER TO THE INPUT TERMINALS; SECOND RECTIFYING MEANS CONNECTED TO THE INPUT TERMINALS FOR SUPPLYING UNIDIRECTIONAL CURRENT TO THE MOTOR FIELD, ARMATURE VOLTAGE SENSING MEANS CONNECTED IN PARALLEL WITH SAID MOTOR ARMATURE; ARMATURE CURRENT SENSING MEANS CONNECTED IN SERIES WITH SAID MOTOR ARMATURE AND ARRANGED SO THAT THE TWO SENSING MEANS PRODUCE OPPOSING VOLTAGES GIVING A RESULTANT VOLTAGE PROPORTIONAL TO THE SPEED OF SAID MOTOR; MEANS FOR INTRODUCING A PORTION OF SAID RESULTANT VOLTAGE INTO SAID CONTROL CIRCUIT TO REGULATE THE CONDUCTION OF SAID CONTROLLED RECTIFIERS IN ACCORDANCE WITH THE SPEED OF THE MOTOR; AND MEANS FOR SHUNTING THE RIPPLE COMPONENT OF THE ARMATURE VOLTAGE FROM SAID RESULTANT VOLTAGE.