Abstract: An optical controlling circuit and an electrical controlled circuit such as a motor control circuit are interconnected by an electro-optic interface. A passive optical switch located in the optical circuit at a position remote from the electrical circuit is physically actuated to generate a change in optical transmission state of the optical circuit. At the electro-optic interface, the change in optical transmission state of the optical circuit is detected and triggers a change in the electrical transmission state of the electric circuit. Embodied as STOP and START pushbuttons, a pair of such passive optical switches at a position remote from the electric circuit reduces the risk that actuating motor control circuits and the like will cause arcing and, in hazardous environments, explosion.

Abstract: An optical controlling circuit and an electrical controlled circuit such as a motor control circuit are interconnected by an electro-optic interface. A passive optical switch located in the optical circuit at a position remote from the electrical circuit is physically actuated to generate a change in optical transmission state of the optical circuit. At the electro-optic interface, the change in optical transmission state of the optical circuit is detected and triggers a change in the electrical transmission state of the electric circuit. Embodied as STOP and START pushbuttons, a pair of such passive optical switches at a position remote from the electric circuit reduces the risk that actuating motor control circuits and the like will cause arcing and, in hazardous environments, explosion.