A microprocessor-controlled airfield lighting control and monitoring system having bi-directional communication between the controlling microprocessor and the airfield lights and/or sensors. The system also includes a metal container for the remote control microprocessor and an improved attachment arrangement for the power transistor associated therewith. A DC power supply is connected to the remote controller microprocessor and has an integrated circuit adapted to sense a threshold voltage, which causes the power transistor to short around the associated power source.