Designing dimmable electronic ballast with frequency control

Abstract

This paper provides a guideline for designing a frequency controlled dimmable electronic ballast for the fluorescent lamp. The design equations are derived based on a power-dependent lamp model. The dimming characteristics of a fluorescent lamp by frequency control can be predicted by incorporating the lamp model into the electronic ballast. The circuit parameters are designed by considering both the starting voltage and the filament power during the dimming operation. An electronic ballast with the half-bridge series-resonant parallel-load inverter is used as an example for illustrating the design procedure. The calculated results are verified by experimental tests on a laboratory prototype circuit.