Logic circuit utilizing a latch type switching device as a permanent memory element

Claim 1

AN ELECTRICAL CIRCUIT SHIFTABLE BETWEEN BISTABLE CONDITIONS COMPRISING; A PAIR OF DIRECT CURRENT SUPPLY TERMINALS, A PAIR OF ELECTRONIC VALVES CONNECTED TO BE SUPPLIED FROM SAID TERMINALS AND CROSS-CONNECTED TO DEFINE A BISTABLE CIRCUIT SUCH THAT EITHER OF SAID VALVES MAY BE IN A HIGH CONDUCTION STATE BUT NOT BOTH SIMULTANEOUSLY, MEANS FOR SHIFTING SAID CIRCUIT BETWEEN ITS BISTABLE CONDITIONS, A SWITCH TRANSFERABLE BETWEEN A PAIR OF CIRCUIT CONTROLLING CONDITIONS, ENERGIZABLE MEANS FOR TRANSFERRING SAID SWITCH BETWEEN ITS CONDITIONS CONNECTED TO BE ENERGIZED BY CURRENTS OF OPPOSITE POLARITY DEPENDING UPON WHICH OF SAID VALVES IS IN A HIGH CONDUCTION STATE, SAID SWITCH BEING TRANSFERRED TO ONE OR THE OTHER OF ITS CONDITIONS DEPENDING UPON THE POLARITY OF ENERGIZATION OF SAID ENERGIZABLE MEANS, SAID SWITCH HAVING A LATCHING CHARACTERISTIC SO THAT IT REMAINS IN THE CONDITION TO WHICH IT IS TRANSFERRED SUBSEQUENT TO DEENERGIZATION OF SAID ENERGIZABLE MEANS, AND A PAIR OF BIAS CIRCUITS FOR SAID VALVES EACH OPERATABLE WHEN IN AN EFFECTIVE CONDITION TO CAUSE ITS ASSOCIATED VALVE TO CONDUCT TO A GREATER EXTENT THAN THE OTHER VALVE IN RESPONSE TO APPLICATION OF POWER TO SAID TERMINALS, SAID SWITCH CONTROLLING THE EFFECTIVE CONDITIONS OF SAID BIAS CIRCUITS SUCH THAT A SEPARATE BIAS CIRCUIT IS PLACED IN AN EFFECTIVE CONDITION FOR EACH CONDITION OF THE SWITCH, SAID SWITCH BEING IN A CONDITION EFFECTIVE TO PLACE A SELECTED BIAS CIRCUIT IN AN EFFECTIVE CONDITION WHEN THE VALVE ASSOCIATED WITH THE SELECTED BIAS CIRCUIT IS LAST IN A HIGH CONDUCTION STATE PRIOR TO A POWER INTERRUPTION.