Abstract: A power supply for a cold cathode tube has a high voltage module coupled directly to the cold cathode tube, and a power control module that provides a power control signal to the high voltage module via low voltage wiring. The power control module has a circuit that compensates for negative resistance of the ionized gas within the cold cathode tube by adjusting a frequency of the power control signal. The power control module also receives a return of from the cold cathode tube, and varies an illumination intensity of the cold cathode tube using a burst modulation technique, and provides shutdown in the event of a ground fault.