Edge-lit LED driver의 효율 향상을 위한 연구

Abstract

This thesis proposes a method of improving power conversion efficiency of a dc-dc boost converter for edge-lit LED Backlight Units (BLUs). The proposed method uses a passive snubber circuit which consists of an inductor, two capacitors and two diodes

it reduces switching loss while increasing the output voltage two times as high as that for the conventional boost converters under the same switching duty ratio. The proposed boost converter was built and tested at output powers of 33 W, 40 W, and 45.6 W. The power conversion efficiency for 24 V input was measured as 94, 93.6, and 93 % for 33 W, 40 W, and 45.6 W, respectively. The measured power efficiencies are 13.4, 13.3, and 13 % higher than those of the conventional boost converters operating at the corresponding output powers. The proposed boost converter ensured reliable operation and high-power efficiency under ± 10 % variation of input voltage and 25 - 100 % variation of the output current dimming duty ratio.