| 摘要 |
<p>An overspeed detector relay is governed by outputs of an oscillator and a tachometer frequency generator through a high-pass filter and amplifier. A step-up transformer is provided having a primary winding energized by output of the amplifier, and control apparatus is provided for the detector relay including a full-wave rectifier connected across a resistor and a winding of the detector relay in series for energizing the detector relay by output of a secondary winding of the step-up transformer. This makes the detector relay quick to respond to de-energization since the shunting effect of the full-wave rectifier is reduced by the series resistor that serves to isolate the relay coil from the rectifier.</p> |
