Abstract: A power circuit for a fluorescent discharge lamp comprising a converter for producing a DC output. A voltage controlled oscillator is driven by the output from the converter, the oscillator providing a high voltage output for driving the lamp. The frequency of the output increases and decreases with increases and decreases in the powering voltage from the converter. A current detector detects the current passing through the lamp and controls the output voltage of the converter according to that current to increase the the voltage to strike the lamp and then control the voltage to give the required running current.