Power switching circuit

Claim 1

IN AN A.C. CIRCUIT INCLUDING A SOURCE OF A.C. VOLTAGE AND A LOAD TO BE SUPPLIED WITH CURRENT FROM SAID SOURCE OF A.C. VOLTAGE, BI-DIRECTIONAL THRESHOLD SEMICONDUCTOR SWITCH MEANS FOR CONTROLLING THE FLOW OF CURRENT BETWEEN SAID SOURCE OF A.C. VOLTAGE AND THE LOAD, SAID SEMICONDUCTOR SWITCH MEANS HAVING A PAIR OF MAIN LOAD TERMINALS CONNECTING THE SAME BETWEEN SAID VOLTAGE SOURCE AND LOAD AND TWO SECTIONS OF SEMICONDUCTOR MATERIAL HAVING THEIR OUTERMOST PORTIONS CONNECTED TO SAID MAIN LOAD TERMINALS AND THEIR INNERMOST PORTIONS ELECTRICALLY JOINED BY MEANS FORMING INTERMEDIATE TERMINAL MEANS WHEREIN SAID SECTIONS OF SEMICONDUCTOR MATERIAL ACT AS SERIALLY CONNECTED LAYERS OF SEMICONDUCTOR MATERIAL THROUGH WHICH COMMON LOAD CURRENT MAY FLOW, EACH OF SAID SECTIONS OF SEMICONDUCTOR MATERIAL COMPRISING SEMICONDUCTOR MATERIAL HAVING ONE STATE WHEREIN AT LEAST PORTIONS THEREOF BETWEEN THE ASSOCIATED LOAD TERMINAL AND INTERMEDIATE TERMINAL MEANS ARE IN ONE CONDITION WHICH IS OF HIGH RESISTANCE AND SUBSTANTIALLY AN INSULATOR FOR BLOCKING THE FLOW OF CURRENT THERETHROUGH IN EITHER OR BOTH DIRECTIONS WHEN THE PEAK VALUE OF AN A.C. VOLTAGE APPLIED TO THE ASSOCIATED TERMINALS IS BELOW A THRESHOLD VOLTAGE LEVEL, AND BEING DRIVEN INTO ANOTHER STATE WHEREIN SAID AT LEAST PORTIONS THEREOF BETWEEN THE ASSOCIATED TERMINALS ARE IN ANOTHER CONDITION WHICH IS OF LOW RESISTANCE AND SUBSTANTIALLY A CONDUCTOR FOR CONDUCTING THE FLOW OF CURRENT THERETHROUGH IN EITHER OR BOTH DIRECTIONS WHEN THE PEAK VALUE OF THE A.C. VOLTAGE APPLIED TO THE ASSOCIATED TERMINALS IS RAISED ABOVE SAID THRESHOLD VOLTAGE LEVEL AND REVERT TO SAID BLOCKING CONDITION WHEN THE CURRENT FLOW THERETHROUGH IS REDUCED BELOW A GIVEN HOLDING LEVEL, THE PEAK VALUE OF THE OUTPUT OF SAID SOURCE OF A.C. VOLTAGE BEING LESS THAN THE SUM OF THE THRESHOLD VOLTAGE LEVELS OF BOTH OF SAID SECTIONS OF SEMICONDUCTOR MATERIAL, AND MEANS FOR CONTROLLING THE STATES OF SAID SECTIONS OF SEMICONDUCTOR MATERIAL, WHICH MEANS INCLUDES A CONTROL CIRCUIT EXTENDING BETWEEN ONE OF SAID MAIN LOAD TERMINALS AND SAID INTERMEDIATE TERMINAL MEANS WHEREIN ONE OF SAID SEMICONDUCTOR SECTIONS IS IN PARALLEL AND THE OTHER SEMICONDUCTOR SECTION IS IN SERIES WITH THE CONTROL CIRCUIT, AND SAID CONTROL CIRCUIT INCLUDING CONTROL MEANS FOR PROVIDING A FIRST CONDITION OF SAID CONTROL CIRCUIT WHERE THE VOLTAGE APPLIED ACROSS THE TERMINALS OF THE SERIES CONNECTED SECTION OF SEMICONDUCTOR MATERIAL EXCEEDS THE THRESHOLD VOLTAGE LEVEL THEREOF TO FIRST DRIVE THE SAME TO SAID CONDUCTING CONDITION WHICH MODIFIES THE VOLTAGE CONDITIONS OF THE CIRCUIT IMMEDIATELY TO APPLY ACROSS THE TERMINALS OF THE PARALLEL CONNECTED SECTION OF SEMICONDUCTOR MATERIAL A VOLTAGE WHICH EXCEEDS THE THRESHOLD VOLTAGE LEVEL THEREOF TO DRIVE THE SAME OF SAID CONDUCTING CONDITION, AND A SECOND CONDITION OF THE CONTROL CIRCUIT WHERE THE VOLTAGE ACROSS THE TERMINALS OF THE SERIES CONNECTED SECTION OF SEMICONDUCTOR MATERIAL IS INSUFFICIENT TO MAINTAIN THE CONDUCTING CONDITION THEREOF AND, AFTER REVERTING TO SAID BLOCKING CONDITION TERMINATES CONDUCTION OF THE PARALLEL CONNECTED SECTION OF SEMICONDUCTOR MATERIAL.