A unique electronic controller design using one sliding damper to function as a return and fresh air mixing process instead of using two separate dampers. This design utilizes one actuator for one damper for both fresh air and return air.

The controller is designed to operate a 12 VDC actuator to slide the damper to the required position. The controllers receive inputs from supply air temperature and outdoor temperature or enthalpy digital signal.

One damper control system saves cost and space in the packaged air conditioning unit.