A high power factor flyback-half-bridge converter for fluorescent lighting

This paper presents the analysis, design and practical considerations of a high power factor electronic ballast for fluorescent lamps. The proposed topology is the combination of a flyback converter and a half-bridge series-resonant parallel-loaded inverter. The high power factor is guaranteed by the use of a flyback converter operating in discontinuous-conduction mode. The high-frequency supply of the lamp is given by the half-bridge converter. The self-oscillating technique is employed, which increases the converter reliability with great simplicity and low cost. In spite of it simplicity, a high performance concerning load and supply is achieved, ensuring a sinusoidal and in-phase supply current