Complete analysis and performance-characteristic compromise for self-excited half-bridge parallel resonant electronic ballasts

This paper presents the complete circuit analysis and performance characteristic compromise for self excited half-bridge parallel resonant electronic ballasts. The operational principles of the ballasts taking parasitic devices into account are described in detail from which the excitation frequency as well as the voltage and current stresses imposed on switching devices are calculated. The design procedure, consequently, can be outlined to determine the component values so the lamp starting voltage, crest factor, cathode fall and component stresses are minimized. In addition, the effects of partial lamp removal during steady state operation and start-up transients are taken into account in the system design. Experimental results are used to verify the theoretical discussion