| 摘要 |
A circuit (70A) controls power supply to an electric motor (80) and de-energizes the motor when an overload state, indicated by a detected reduction in motor rotational speed, occurs. Rotational speed is monitored by a pulse detector (143) which detects pulses occurring at a motor terminal (T1) due to motor polarity switching. A particular application for the control circuit is driving the motor of an automatic car window, wherein a reduction in motor rotational speed may be due to an object trapped between window and frame during window closure. <IMAGE> |
