| 摘要 |
A circuit means by which a high voltage, complex load may be precisely sensed and controlled. With high voltage AC loads, the effect of unavoidable stray capacitances is to render extremely difficult to measure and/or control that portion of total current which contributes actual power; that is, the resistive portion. Herein described is a circuit for rejecting all capacitive currents while measuring only the true resistive portion and deriving from the signal a filtered (averaged) voltage suitable for regulation and/or control. The circuit samples the total current only during the time when there is no capacitive current flowing. This sample is then compared with a reference, the difference amplified, and then averaged over many samples to derive a precise control signal.
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