Low-cost self-oscillating electronic ballast for T5 fluorescent lamp integrated with HPF Class-DE resonant rectifier

This paper presented the low-cost self-oscillating electronic ballast with a broken filament automatic shutdown for T5/28W fluorescent lamp based on high power-factor Class-DE resonant rectifier, which are very attractive in term of commercial production. The power factor-correction is achieved by using a bridge rectifier which acts as the Class-DE rectifier with Class-D resonant inverter. By using this topology the conduction angle of the diode can be increased then the low line current harmonic, high-power-factor was obtained. The switching frequency is about 50 kHz. Simulation results verify the theoretical analysis.