| 摘要 |
<p>A protective circuit connected between a source and a load tests the source voltage for proper polarity and amplitude prior to permitting interconnection of the source and the load. A diode-resistor network adapted to respond to source voltage polarity and amplitude and a circuit breaker pole form a series circuit with the source whereby overvoltage or improper polarity provides sufficient current to trip the breaker. The application of source voltage to the load is delayed for a time greater than the circuit breaker tripping time so that the polarity and amplitude test of the source voltage is completed prior to connection of the source to the load.</p> |
