| 摘要 |
<p>A starting control circuit (30) is provided for use with a mechanical duty single phase alternating current motor having a start winding (10) and a main or run winding (12). Both the main (12) and start (10) windings are electrically connected to the alternating current source (14) during the initial starting of the motor. Transducers (16, 24) detect the current phase of both the start (10) and main (12) winding and comparators (32, 34) then compare these current phases together. A comparator (36) generates a pulsed output signal when the phase of the start winding (10) lags the phase of the main winding (12) and this pulsed output signal has a pulse width proportional to the magnitude of the phase lag between the start (10) and main (12) windings. These pulsed output signals are integrated and an electronic switch (20) is activated to disconnect the start winding (10) from the power source (14) whenever the integrated pulsed output signals exceed a predetermined value.</p> |
