Patent ID: 9722462
Date: 2017-08-01
CPC Classifications: H02J

Claim:
1. A resonant power source comprising: a source circuit that includes a source coil, an ac driver with a first resistance, representing an equivalent output impedance of the ac driver, and a matching network; a current probe that measures a magnitude signal of an instantaneous source coil current; an amplifier that receives and compares the magnitude signal and a target signal, and produces an error signal proportional to the difference; and a compensation filter that receives the error signal and produces a control voltage that determines an ac driver voltage of the ac driver, wherein the current probe further measures a phase of the instantaneous source coil current, and the resonant power source further comprises: a voltage probe that measures a phase of the ac driver voltage; and a phase detector that receives and compares the phase of the instantaneous source coil current and the phase of the ac driver voltage, and produces an output signal proportional to a phase difference between the phase of the instantaneous source coil current and the phase of the ac driver voltage, wherein an impedance of a variable element in the source circuit is determined according to the output signal.