A universal power operator for shifting a movable barrier, such as a gate, and a circuit control system for operation thereof, is shown that allows the operator to be assembled for both a left-hinged or right-hinged movable barrier. The universal power operator includes generally an actuator arm, a housing assembly, a gear assembly, and a modular drive motor. The housing assembly contains generally symmetrical portions allowing the user to interchangeably assemble the motor in one of two positions for use with a left-hinged or right-hinged movable barrier.