Control circuit for electron valve in motor control system

Claim 1

A MOTOR SYSTEM COMPRISING A SOURCE OF PERIODIC SUCCESSIVE UNIPOLAR WAVES, SAID SOURCE HAVING FIRST AND SECOND OUTPUT TERMINALS OF OPPOSITE POLARITY, A CONTROLLED ELECTRIC VALVE HAVING A CONTROL ELECTRODE AND FIRST AND SECOND POWER ELECTRODES, WHICH VALVE WITH FORWARD VOLTAGE APPLIED THEREACROSS IS RENDERED ABRUPTLY CONDUCTIVE IN THE FORWARD DIRECTION IN RESPONSE TO THE APPLICATION OF A CONDUCTION INITIATING CONTROL SIGNAL TO ITS CONTROL ELECTRODE, MEANS COUPLING SAID FIRST OUTPUT TERMINAL TO SAID FIRST POWER ELECTRODE, AN ELECTRIC MOTOR INCLUDING FIELD MEANS AND AN ARMATURE WINDING, A FIRST CIRCUIT INCLUDING SAID ARMATURE WINDING CONNECTED BETWEEN SAID SECOND OUTPUT TERMINAL AND SAID SECOND POWER ELECRODE, AN ASYMMETRIC PATH CONNECTED ACROSS SAID FIRST CIRCUIT, SAID ASYMMETRIC PATH BEING OPPOSITELY POLARIZED RELATIVE TO SAID VALVE, A CONTROL CIRCUIT FOR SUPPLYING CONDUCTION INITIATING CONTROL SIGNALS TO SAID CONTROL ELECTRODE, SAID CONTROL CIRCUIT COMPRISING INTERMEDIATELY TAPPED D.C. PASSABLE FIRST RESISTIVE MEANS D.C.-COUPLED BETWEEN SAID FIRST OUTPUT TERMINAL AND SAID SECOND POWER ELECTRODE, D.C.-PASSABLE SECOND RESISTIVE MEANS HAVING ONE END D.C.-COUPLED TO AN INTERMEDIATE TAP OF SAID FIRST RESISTIVE MEANS, THE OTHER END OF SAID SECOND RESISTIVE MEANS BEING D.C.-COUPLED TO SAID CONTROL ELECTRODE, A FIRST CAPACITOR COUPLED BETWEEN SAID TAP AND SAID SECOND POWER ELECTRODE TO PROVIDE A FIRST RC CIRCUIT INCLUDING SAID CAPACITOR AND SAID FIRST RESISTIVE MEANS AND HAVING AN OUTPUT ACROSS SAID CAPACITOR, AND A SECOND CAPACITOR COUPLED BETWEEN SAID SECOND POWER ELECTRODE AND SAID OTHER END OF THE SECOND RESISTIVE MEANS TO PROVIDE A SECOND RC CIRCUIT INCLUDING THE SECOND CAPACITOR AND THE SECOND RESISTIVE MEANS, THE SECOND RC CIRCUIT BEING INTERPOSED BETWEEN THE FIRST RC CIRCUIT AND SAID CONTROL ELECTRODE, SAID SECOND RC CIRCUIT HAVING AN OUTPUT ACROSS SAID SECOND CAPACITOR WHICH IS APPLIED ACROSS THE CONTROL ELECTRODE AND THE SECOND POWER ELECTRODE.