Patent ID: 8330376

Claim:
A method of providing light, comprising: rectifying an AC power source to provide DC power; applying pulses of the DC power to an inductor, the inductor providing high voltage pulses; adjusting the high voltage pulses according to a duty cycle of the AC power source; rectifying the high voltage pulses with voltage multiplying and rectifying apparatus to provide high voltage DC power; applying the high voltage DC power between an anode and a cathode of a cathodoluminescent device to provide light; wherein the pulses of the DC power are adapted in at least one of pulse width and pulse rate to optimize a power factor; the adaptation for optimizing power factor including providing the pulses of the DC power applied to the inductor with a wider pulsewidth during shoulder regions of a sinusoidal waveform of the AC power source than during peak regions of the sinusoidal waveform of the AC power source.