Door operator drives barrier to complete closure

摘要

A door operator includes an electric motor to drive the door between open and closed position through a transmission, a position detector to detect the position of the door, a learn routine to determine a minimum reversal position that is located a short distance above the close limit and a controller to control the operation of the motor. The controller responds to a close command to move the door to a closed position and responds to the detection of the door at the minimum reversal position to cause the motor to continue to operate for a predetermined period of time prior to shutting off the motor to effectively drive the door to the close limit.