Controllable electrical switch

Claim 1

A controllable electrical switch, comprising: first and second terminals; and actuating means for making electrical connection between said terminals when closing said switch, and for breaking said electrical connection when opening said switch; said actuating means including: a. a bistable electromechanical relay having an input electrode coupled to said first terminal and an output electrode coupled to said second terminal, and conditionable to one of a low and high impedance state between its input and output electrodes as a function of current flow therein; b. a pair of semiconductor control devices, each having an input circuit, and each having an output circuit respectively coupled to said electromechanical relay such that a conductivity condition in one of said devices produces a current flow in said relay as to place it in its low impedance state and such that a conductivity condition in the other of said devices produces a current flow in said relay as to place it in its high impedance state; c. a pair of pulse triggering circuits for signal pulsing the input circuits of said semiconductor control devices to change the conductivities thereof, with said changes in conductivity conditions serving to change the current flow through the output circuits of said control devices to change the impedance state of said bistable relay in actuating said electrical switch from a make to a break condition and vice versa; d. a first power supply means for energizing said bistable electromechanical relay and said pair of semiconductor control devices; and e. a second power supply means for energizing said pulse triggering circuits at a lower potential than energizes said bistable relay and said pair of control devices.