Abstract
Due to the environmental and cost considerations, application of cold cathode fluorescent lamps (CCFLs) as the backlight system is now replacing with novel external electrode fluorescent lamps (EEFLs) backlight system for large-sized LCD TV. In fact this is also the motivation of conducting this research. Basically, the contributions of this thesis can be summarized follows. First, the inherent uniform equivalent capacitance of the EEFLs are fully used for the proposed full bridge resonant inverter to provide a uniform current sharing capability for the backlight of the large sized LCD TV. Second, the thesis provides a simple dimming-circuit‚ which modulates the sequences of power switches, for acquiring the dimming feature of EEFLs. Third, in order to reduce the inverter rating and increase the efficiency, an inductor is added to the secondary winding of the transformer for reactive power compensation. Due to the large number of EEFLs‚ say ten in this thesis, the efficiency is increased about 10% approximately. Finally, a prototype system is constructed to verify feasibility of the proposed backlight system.