Patent ID: 7642728

Claim:
A circuit comprising: first and second line terminals and first and second input terminals, a first impedance element connected between the first line terminal and the first input terminal and a second impedance element connected between the second line terminal and the second input terminal; a rectifier circuit coupled to the first and second input terminals; a resonant circuit coupled to the rectifier circuit, the resonant circuit including a resonant inductor, a resonant capacitor, and first and second rails, first and second load terminals to enable the resonant circuit to energize a load; wherein the resonant capacitor includes first and second resonant capacitors coupled in series across the first and second load terminals; and a voltage feedback path for a feedback signal extending from a point between the first and second resonant capacitors to a point between the first and second line terminals so that a potential at the load substantially tracks a potential at the first and second input terminals, wherein at least one of the first and second impedance elements is connected inside the feedback loop so as to impede feedback current from flowing through the voltage feedback path.