Series inverter circuit having controlled rectifiers with power diodes in reverse parallel connection

Claim 1

AN INVERTER CIRCUIT COMPRISING A PAIR OF DIRECT CURRENT INPUT TERMINALS, A CAPACITOR CONNECTED IN CIRCUIT WITH SAID INPUT TERMINALS, A PAIR OF CONTROLLED RECTIFIERS CONNECTED IN SERIES CIRUCIT RELATIONSHIP ACROSS SAID INPUT TERMINALS, A LOAD CIRCUIT HAVING A RESISTIVE PORTION AND AN INDUCTIVE PORTION, MEANS CONNECTING SAID INPUT TERMINALS WITH SAID CONTROLLED RECTIFIERS AND SAID LOAD CIRCUIT TO PROVIDE A CURRENT PATH FOR ENERGIZING SAID LOAD CIRCUIT WITH HALF CYCLES OF CURRENT FLOW OF OPPOSITE DIRECTION, SAID CAPACITOR BEING CHARGED AND DISCHARGED DURING EACH CYCLE, A PAIR OF POWER DIODES CONNECTED IN REVERSE PARALLEL RELATIONSHIP WITH SAID CONTROLLED RECTIFIERS, FIRING CIRCUIT MEANS CONNECTED IN CIRCUIT WITH SAID CONTROLLED RECTIFIERS TO PROVIDE A PULSE OF CURRENT TO ALTERNATELY TRIGGER ONE AND THEN THE OTHER OF SAID CONTROLLED RECTIFIERS, SAID FIRING MEANS PROVIDING A DELAYED CURRENT PULSE TO THE PREVIOUSLY NONCONDUCTING CONTROLLED RECTIFIER TO FIRE IT AFTER A PREDETERMINED DELAY FOLLOWING THE CESSATION OF CURRENT FLOW THROUGH THE OTHER CONTROLLED RECTIFIER, SAID PAIR OF POWER DIODES CARRYING THE MAIN CURRENT FLOW DURING THE COMMUTATION OF SAID CONTROLLED RECTIFIERS.