| 摘要 |
948,278. Control of A.C. motors. A. KENYON. Nov. 12, 1962 [Aug. 11, 1961], No. 29013/61. Heading H2J. [Also in Division E2] An electric motor 15 driving a garage door is adapted to be started by the energization of an induction coil 36 in response to a magnetic pulse emitted from a motor vehicle. The motor control system includes a coil 44 in circuit with a transistor amplifier 31, comprising transformer 37, rectifier 38, condensers 39, 40, resistor 41 and transistors 42, and a coil 43 wound around coil 44 and in circuit with the induction coil 36. Energization of the induction coil in response to energization of a solenoid carried by the vehicle sets up a positive feed-back in the coil 43 sufficient to hold closed a switch 44a operated by coil 44. Switch 44a energizes coil 48 to close switch 49 thereby energizing coil 45 of the motor starter unit 33 to start the motor. Whilst the door is opening the vehicle solenoid is de-energized thereby cutting out the amplifier 31 and opening switch 44a. When the door reaches the fully open position one of the limit switches 26 closes, thereby exciting the coil 48 and opening the single pulse relay switch 49 to de-energize the motor starter unit 33 to stop the motor. During opening or closing movement of the door a reversing switch 27 in the motor start winding is actuated so that if, after the door has opened, the vehicle solenoid is again energized the cycle of operations is repeated with the motor in reverse to close the door. When the door reaches its fully closed position the other of the limit switches 26 is closed. Safety switches 25 adapted to be opened if the movement of the door is obstructed are provided in series with the switch 49. |
