Electrical control systems

Claim 1

IN A REGULATING SYSEM FOR CONTROLLING AN INVERTER OF THE TYPE COMPRISING A D.C. MOTOR DRIVING AN A.C. GENERATOR, THE COMBINATION OF TWO CONTROLLED RECTIFIERS; CIRCUIT MEANS FOR ENERGIZING THE FIELD WINDING OF THE GENERATOR AND THE FIELD WINDING OF THE MOTOR FROM A SOURCE OF DIRECT CURRENT, WHEREBY ONE OF SAID CONTROLLED RECTIFIERS CAN BE OPERATED TO CONTROL ENERGIZATION OF THE FIELD WINDING OF THE MOTOR AND THE OTHER OF THE CONTROLLED RECTIFIERS CAN BE OPERATED TO CONTROL ENERGIZATION OF THE FIELD WINDING OF THE GENERATOR; A FIRST TIMING CIRCUIT RESPONSIVE TO THE ALTERNATING OUTPUT OF SAID GENERATOR AND CONNECTED TO RENDER SAID ONE CONTROLLED RECTIFIER CONDUCTIVE AT A TIME, DURING EACH CYCLE OF SAID OUTPUT, DEPENDENT UPON THE FREQUENCY OF SAID OUTPUT; A SECOND TIMING CIRCUIT RESPONSIVE TO SAID OUTPUT AND CONNECTED TO RENDER THE OTHER OF SAID CONTROLLED RECTIFIERS CONDUCTIVE, DURING EACH CYCLE, DEPENDENT ON THE MAGNITUDE OF SAID OUTPUT; AND COMMUTATING CIRCUIT MEANS BEING RESPONSIVE TO SAID OUTPUT TO RENDER BOTH OF SAID CONTROLLED RECTIFIERS NONCONDUCTIVE AT SUBSTANTIALLY THE SAME INSTANT DURING EACH CYCLE OF SAID OUTPUT.