A Study on the design and performance of electronic ballast for CCFL dimming control with frequency modulation

Commonly, CCFL dimming methods are used to either lamp current regulation or average current adjust feeding the CCFL inverter. And inverter operation frequency is higher than resonant frequency for safe operation. In this study, we design the half-bridge type series and parallel resonant converter circuit that switches at variable frequency modulation method to control the output power. This method has advantage such as low EMI and reduced harmonics, and it is convenient to dimming control with microprocessor. The validity of this study is confirmed from the simulation and experimental results.