D.c.-a.c. converter for producing high frequency outputs

Claim 1

A D.C. TO A.C. CONVERTER FOR PRODUCING HIGH FREQUENCY OUTPUTS, COMPRISING, IN COMBINATION: (A) A BRIDGE CIRCUIT INCLUDING FOUR CONTROLLABLE SEMICONDUCTOR RECTIFIER ELEMENTS AND DEFINING TWO D.C. INPUT TERMINALS AND TWO A.C. OUTPUT TERMINALS; (B) AN INDUCTANCE; (C) RECTIFIER MEANS FOR SUPPLYING A D.C. VOLTAGE CONNECTED TO SAID D.C. INPUT TERMINALS VIA SAID INDUCTANCE; (D) OUTPUT MEANS CONNECTED BETWEEN SAID A.C. OUTPUT TERMINALS AND INCLUDING A VARIABLE RESISTANCE, AN INDUCTANCE, AND A CAPACITANCE ALL CONNECTED IN PARALLEL TO FORM A PARALLEL RESONANT CIRCUIT; AND (E) A CONTROL PULSE SOURCE CONNECTED TO THE CONTROL ELECTRODES OF SAID SEMICONDUCTOR RECTIFIER ELEMENTS FOR DELIVERING CONTROL PULSES THERETO AT A RATE GREATER THAN TWICE THE RESONANT FREQUENCY OF SAID RESONANT CIRCUIT, WHEREBY EACH SUCH PULSE OCCURS AT LEAST A PREDETERMINED TIME INTERVAL PRIOR TO THE PASSAGE OF THE VOLTAGE ACROSS SAID OUTPUT TERMINALS THROUGH ZERO AND THE VOLTAGE APPEARING ACROSS SAID OUTPUT TERMINALS HAS A FREQUENCY WHICH IS GREATER THAN THE RESONANT FREQUENCY OF SAID PARALLEL RESONANT CIRCUIT.