System for remotely controlling a load

摘要

A system adapted to remotely control a transformer relay. The load switch of a transformer relay is controlled by controlling the direction of current flow in the secondary winding. A switch module is coupled with two wires to the secondary winding of the transformer relay providing a unidirectional current flow above a predetermined threshold in the secondary winding in response to a control signal. The unidirectional current flow may be selectively controlled in either direction or may be only purely unidirectional. A control module is then coupled to the switch module momentarily producing the control signal in response to an external stimulus. The switch module, the control module, or both draw a quiescent current from the secondary winding of the transformer relay when the switch module is not activated. The quiescent current is of an amount which is less than the predetermined threshold. In one embodiment the voltage and current at the control device are limited to values less than those available at the secondary winding of the transformer relay.