An output circuit providing isolation between inputs and the output employs first and second opto-couplers for isolation. Pulse activation of the first opto-coupler turns on an output transistor and pulse activation of the second opto-coupler turns off the output transistor. An input stage of the output circuit is and light emitting devices of the first and second opto-couplers are powered by a first power source and an output stage of the output circuit is powered from an external power source. Power consumption by the input stage of output circuit occurs only during pulse activation of the first and second opto-couplers.