本文研製一具均流之發光二極體驅動電路，此電路架構包含前級昇壓型功率因數修正電路和後級半橋串聯諧振電路，此驅動電路並具有均流功能，以平衡多串發光二極體之電流。本文將探討發光二極體等效電路對半橋串聯諧振換流器電路特性之影響與其電路動作原理，並對所提出之均流策略進行特性分析與設計考量。最後實際研製一具均流之發光二極體驅動電路，驅動4個發光二極體負載模組，每模組包含15 顆1W白光發光二極體，以驗證理論分析之可行性，輸入電壓可操作於90~260 Vrms，效率為84.3%以上，最高滿載效率為87.9%。

In this thesis, the design and implementation of a LED driver with current balancing are presented. The proposed driver includes a boost power factor correction converter as front-stage and a half-bridge resonant inverter as rear-stage. With the current balancing scheme, the driver is suitable to drive the multi-string LEDs. The effect of the LED equivalent model on the resonant circuit and the driver operating principles are discussed. The design and characteristics of proposed current balancing scheme are also considered. Finally, a two-stage LED driver with current balancing is implemented to drive 4 strings LED module, which contains 15 pieces 1W white light LEDs for each string. Experimental results show that the proposed circuit can be operated at 90~264Vrms AC input voltage range and the highest efficiency is 87.9 %.

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