Patent ID: 6184641
Filing Date: 2001-02-06
Classification: E05F,E05Y,H02P

Abstract:
A barrier operator, comprising:an AC motor having an output shaft, a start coil for creating a temporary starting torque component for the motor and a main coil for driving the motor;a transmission connected to the motor to be driven thereby and for connection to a barrier to be moved; anda controller external to the motor for starting and stopping the motor, the controller comprising:a first relay coupled to the start coil for supplying current having a first polarity to the start coil;a second relay coupled to the start coil for supplying current having a second polarity to the start coil;a current controller coupled to the main coil for supplying current to the main coil; anda decoupler arrangement including an speed sensor external to the motor for sensing output speed of the motor, and a decoupler responsive to the speed sensor means for decoupling the start coil when an output speed of the motor achieves a predetermined percentage of a maximum rated output speed.