| 摘要 |
<p>An electronic control circuit for an electric window winder for a motor car, which allows the window to be moved to a fully open or fully closed position simply by a momentary operation of a push-button. A latch within logic circuit 30 is associated with each push-button 32, 34, and is set by operation of the push-button, to keep the motor 10 energised. If the motor current falls to normal fairly quickly, this shows that the window is moving; any subsequent abnormal rise in current indicates that the window has met an obstruction, or reached the end of its travel, and the latch is then reset, turning the motor off. If the motor current remains abnormally high after starting, the direction of energisation is reversed, to ascertain whether the window is stuck, or at the end of its travel. If the former, the motor is reversed at intervals to free the window; after nine unsuccessful reversals, the latch is reset. If the latter, the motor returns to its original direction, and returns the window to the end of its travel. <IMAGE></p> |
