Importance

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Abstract

A door operator includes a motor-driven mechanism to move a door between an open position and a closed position in response to activation of an improved control circuit. The improved control circuit includes circuitry to initialize the sequence of operation of the motor upon connection of power after installation of the door operator or upon restoration of power after a power outage. Obstruction detection circuitry is also included in the control circuit to stop or reverse the motor if the door encounters an obstacle during movement between the open and closed positions. Time delay circuitry cooperates with the obstruction detection circuitry so as to prevent stopping or reversing the motor due to the inertia of the door and of the drive mechanism as the door starts to open or close upon activation of the control circuit. During the time delay period, however, further manual activation of the control circuit is operative to stop and/or reverse movement of the door. As the door moves in one direction, movement can be stopped and restarted in the opposite direction upon consecutive manual activations of the control circuit. When the door nears the closed position, timer circuitry is activatd to energize the motor for a predetermined time or until sufficient resistance to door movement is met to activate the obstruction detection circuitry whereupon the motor is stopped. Maximum run-time circuitry is also included to set the maximum time allowable for energization of the motor to move the door in either direction between the open and closed positions.

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First Claim