Semiconductor switch

Claim 1

A SEMICONDUCTOR SWITCHING DEVICE ADAPTED TO BE CONNECTED IN A MAIN CURRENT CONDUCTING PATH AND SWITCHED BETWEEN HIGH AND LOW IMPEDANCE MODES INCLUDING IN COMBINATION (A) THREE TERMINALS INCLUDING (A) A PAIR OF MAIN TERMINALS ADAPTED TO BE CONNECTED IN A MAIN CURRENT CARRYING PATH (B) A GATING TERMINAL FOR SWITCHING THE SEMICONDUCTOR SWITCHING DEVICE BETWEEN ITS HIGH AND LOW IMPEDANCE STATES, (B) MONOCRYSTALLINE SEMICONDUCTOR SWITCHING MEANS INCLUDING (A) A PAIR OF SEMICONDUCTOR PELLETS (1) ONE OF SAID SEMICONDUCTOR PELLETS HAVING THREE LAYERS WITH ALTERNATE LAYERS OF OPPOSITE CONDUCTIVITY TYPE THEREBY FORMING A TRANSISTOR WITH TWO OUTER LAYERS OF ONE CONDUCTIVITY TYPE SEPARATED BY A BASE REGION OF OPPOSITE CONDUCTIVITY TYPE, AND (2) THE OTHER ONE OF SAID SEMICONDCUTOR PELLETS CONSISTING OF FOUR LAYERS WITH ALTERNATE LAYERS OF OPPOSITE CONDUCTIVITY TYPE FORMING A FOUR LAYER SEMICONDUCTOR SWITCH OF THE GATE TURN OFF TYPE, (3) SAID TRANSISTOR HAVING ITS TWO OUTER LAYERS ELECTRICALLY CONNECTED BETWEEN SAID PAIR OF MAIN TERMINALS SO THAT ITS THREE LAYERS ARE IN THE MAIN CURRENT CONDUCTING PATH OF THE SWITCHING DEVICE AND (4) EACH OF ITS THREE LAYERS IS ELECTRICALLY CONNECTED TO THREE CONSECUTIVE LAYERS OF SAID GATE TURN OFF DEVICE IN SUCH A MANNER THAT CONNECTED LAYERS ARE OF LIKE CONDUCTIVITY WHEREBY CURRENT TO THE BASE OF SAID TRANSISTOR IS SUPPLIED BY SAID GATE TURN OFF DEVICE (5) THE LAYER OF SAID GATE TURN OFF DEVICE WHICH IS ELECTRICALLY CONNECTED TO THE BASE LAYER OF SAID TRANSISTOR BEING ELECTRICALLY CONNECTED TO SAID GATING TERMINAL WHEREBY SAID GATE TURN OFF DEVICE CAN BE RENDERED SELECTIVELY CONDUCTIVE AND NON-CONDUCTIVE RESPECTIVELY IN RESPONSE TO SIGNALS AT SAID GATE THEREBY TO RENDER SAID TRANSISTOR SELECTIVELY CONDUCTIVE AND NON-CONDUCTIVE RESPECTIVELY AND THUS CAUSE THE SWITCHING DEVICE SELECTIVELY TO PRESENT A LOW AND HIGH IMPEDANCE RESPECTIVELY IN THE MAIN CURRENT CONDUCTING PATH.