Control of power pulses to motor of door operator to ensure constant acceleration and deceleration of motor

摘要

A door operator electric motor drives the door between open and closed positions using a transmission. A motor control circuit receives a series of pulses and responsive to the pulses starts the motor and drives the motor in one or the other direction. A controller controls the length of the pulses in the pulse signal in accordance with a predetermined set of values wherein accordingly the speed of the motor is linearly varied from zero to a maximum speed and from the maximum speed to zero. This linear acceleration and deceleration facilitates a slow and smooth start and stop for movement of the door reducing impulse forces if an obstruction is encountered near the fully open or fully closed positions.