Voltage-frequency control dimming method for T5 fluorescent lamps

Abstract

This paper presents a dimmable electronic ballast for T5 fluorescent lamp. A modified dimming method is proposed based on variable DC bus and dedicated IR21592 IC. A combined method of dc link voltage control of resonant inverter, and a fixed phase angle of resonant inverter that is kept constant using the phase-locked loop (PLL) is employed. The electrodes heating is evaluated in order to guarantying the correct lifetime of T5 fluorescent lamp using Sum of Squares (SoS) method. Simulation, mathematical analysis, and experimental results with IR21592 IC were demonstrated for different operation conditions.