Increased efficiency commutation circuit for thyristors

Claim 1

A COMMUTATION CIRCUIT FOR USE WITH A VOLTAGE SOURCE AND LOAD TERMINALS COMPRISING, IN COMBINATION, A LOAD CURRENT CARRYING THYRISTOR, MEANS CONNECTING SAID THYRISTOR TO SUPPLY ENERGY TO THE LOAD TERMINALS FROM THE VOLTAGE SOURCE, A COMMUTATING THYRISTOR FOR SAID LOAD CARRYING THYRISTOR, A REACTIVE NETWORK INCLUDING INDUCTANCE MEANS AND COMMUTATING CAPACITANCE MEANS, MEANS CONNECTING AT LEAST PART OF SAID REACTIVE NETWORK IN A SERIES LOOP PATH FOR SAID COMMUTATING THYRISTOR TO APPLY TO THE LOAD TERMINALS AN ADDITIVE CURRENT FROM SAID COMMUTATING CAPACITANCE MEANS TO SAID LOAD CARRYING THYRISTOR TO EXTINGUISH SAID THYRISTOR, SAID REACTIVE NETWORK INCLUDING A PLURALITY OF SERIES CONNECTED INDUCTIVE AND CAPACITIVE MEANS THEREIN WITH SAID SERIES COMBINATIONS BEING CONNECTED IN PARALLEL, A FIRST OF SAID INDUCTOR-CAPACITOR SERIES COMBINATIONS BEING TUNED TO THE FUNDAMENTAL OF THE COMMUTATING FREQUENCY, AND EACH OF REMAINING OF SAID PLURALITY OF INDUCTORCAPACITOR SERIES COMBINATIONS BEING TUNED TO A HARMONIC (2N-1) TIMES THE COMMUTATING FREQUENCY, WHEREIN N IS ANY POSITIVE INTEGER, WHEREBY SAID REACTIVE NETWORK PROVIDES MORE NEARLY A RECTANGULAR WAVE THAN A SINE WAVE OF A PULSE OF CURRENT TO EXTINGUISH SAID THYRISTOR.