Abstract: The start-up circuit comprises a large valued resistor and a storage capacitor. A voltage sensing switch is connected to the junction of the resistor and storage capacitor on one hand and a voltage doubler on another. The voltage doubler is fed through a capacitor driven by a pair of switching elements arranged in a bridge configuration. The switching elements are driven by a control circuit which is supplied by the start-up and run circuitry. The output of the bridge feeds a resonant tank which is parallel loaded through the resonant capacitor by means of a transformer.