Electronic Ballast with Single Stage Circuit Structure

Abstract

An electronic ballast with a single stage circuit structure includes a detection device for detecting a voltage, current, and phase of an AC input power source; a rectifier bridge; a full bridge inverter circuit; and an inverter controlling circuit. When an output terminal of the full bridge inverter circuit is connected to the gas discharge lamp as a load, the electronic ballast further includes a series resonant capacitor Cs and a series resonant inductor L. By additionally providing the series resonant capacitor Cs and the series resonant inductor L to the electronic ballast, a zero-crossing point of a unidirectional sinusoidal direct current is able to effectively solve the HID extinguishing problem due to under-voltage thereof. Since a conduction angle of the entire unidirectional sinusoidal half wave of the HID is increased, the PF value is effectively increased and the harmonics is effectively reduced.

Dependencies are inferred from the claim text.