High power factor electronic ballast for high pressure sodium lamp

In this paper, an analysis of a high power factor resonant inverter for driving a 150 W HPS lamp and electrical characteristics of the lamp are discussed. The operation of the inverter circuit, in which the lamp is included as a load, is analyzed. Experimental results of the inverter circuit are also presented. Finally, a power factor corrector is connected in cascade with the inverter and a high power factor above 0.99 and low THD on the line current can be achieved.