| 摘要 |
<p>A high voltage power line is provided with a coupling capacitor for connecting a carrier system to the power line and for also providing a voltage divider to indicate the line voltage. The coupling capacitor usually comprises a series of individual capacitors that provide the necessary voltage rating. A load transformer has a primary winding connected across one of the capacitors of the series and has a secondary winding connected to an output load. A control load and a voltage indicator are coupled to the transformer. The indicated voltage is compared to a power line reference voltage, and the relative difference changes the control load so that a substantially constant load is presented to the transformer. Thus, its output voltage at its secondary winding supplying the output load is a more accurate indication of line conditions. When the power line voltage approaches zero, the reference voltage does also, and the control short-circuits the control load to cause the output voltage at the output load secondary winding to approach zero very quickly.</p> |
