Abstract: An electrical circuit for providing an adjustable and highly controllable, high voltage AC waveshape to a load from a low-voltage, DC source. This highly controlled waveshape allows accurate reproduction of almost any low-frequency AC reference through an intermediate high-frequency inverter. The inherent leakage reactance of a high-voltage transformer is used advantageously as a filter for removing the undesired high-frequency component from the output. Economy in parts count and power losses results from the use of a single power handling inverter to perform all adjust, regulation, and waveshape functions.

Abstract: 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.