Inverter circuit with commutation means independent of the load circuit

Claim 1

AN INVERTER INCLUDING A FIRST TRANSFORMER HAVING AN OUTPUT WINDING AND A CENTRE-TAPPED PRIMARY WINDING THE CENTRE TAP OF WHICH IS CONNECTED TO ONE POLE OF A D.C. SOURCE, FIRST AND SECOND CONTROLLED RECTIFIERS CONNECTED RESPECTIVELY TO THE TWO ENDS OF SAID PRIMARY WINDING AND VIA A FIRST CHOKE TO THE OTHER POLE OF SAID D.C. SOURCE, A SECOND TRANSFORMER HAVING A PRIMARY WINDING HAVING A CENTRE TAP CONNECTED TO SAID ONE POLE OF SAID D.C. SOURCE AND FIRST AND SECOND TAPPING POINTS SYMMETRICALLY DISPOSED WITH RESPECT TO SAID CENTRE TAP, THIRD AND FOURTH CONTROLLED RECTIFIERS CONNECTED RESPECTTIVELY TO THE TWO ENDS OF SAID PRIMARY WINDING OF SAID SECOND TRANSFORMER AND VIA A SECOND CHOKE TO SAID OTHER POLE OF SAID D.C SOURCE FIFTH AND SIXTH CONTROLLED RECTIFIERS CONNECTED RESPECTIVELY TO SAID FIRST AND SECOND TAPPING POINTS AND TO SAID OTHER POLE OF SAID D.C. SOURCE VIA SAID SECOND CHOKE, A SECONDARY WINDING ON SAID SECOND TRANSFORMER HAVING A CENTRE TAP CONNECTED TO SAID OTHER POLE OF SAID D.C. SOURCE, FIRST AND SECOND CAPACITORS CONNECTED RESPECTIVELY FOR CHARGING BETWEEN THE TWO ENDS OF SAID SECONDARY WINDING OF SAID SECOND TRANSFORMER AND SAID OTHER POLE OF SAID D.C. SOURCE, FIRST AND SECOND ADDITIONAL WINDINGS ON SAID FIRST CHOKE CONNECTED RESPECTIVELY TO SAID FIRST AND SECOND CAPACITORS AND VIA SEVENTH AND EIGTH CONTROLLED RECTIFIERS TO SAID OTHER POLE OF SAID D.C SOURCE TO PROVIDE A DISCHARGE PATH FOR SAID CAPACITORS, TRIGGER PULSE MEANS FOR APPLYING TRIGGER PULSES TO SAID FIRST CONTROLLED RECTIFIER AND TO SAID THIRD, FIFTH AND SEVENTH CONTROLLED RECTIFIERS TOGETHER TO CHANGE