A circuit includes an input and an output, and an electronic light
generator drive portion that is coupled to the input and drives the
output. In one configuration, the circuit includes a further portion that
is coupled to the input and that tunes a resonance at the input to a
first frequency, the further portion having an additional portion with a
resonance that is tuned to a second frequency different from the first
frequency, and that effects damping of the first frequency at the input.
In a different configuration, the drive portion includes an electronic
switch coupled to the output of the circuit, and a further portion
coupled to the input and having a phase tracking portion, the phase
tracking portion tracking a phase of a signal at the input and producing
a control signal that is used to control the electronic switch.