本論文針對大面積LED照明應用，設計新型高效調光LED驅動器來提升系統效率。招牌背光用LED模組使用12 V或24 V電源系統，並以並聯方式實現大面積顯示照明，每個LED模組都內藏一電阻器或線性穩壓器來調節LED電流，以維持穩定的光通量輸出。本研究提出一新型具混合式整流器之高效率LED驅動器設計，利用半橋式LLC型串聯諧振轉換器的二次側LED電流偵測，來實現全橋整流器和半波整流器的自動變換，提升寬輸出電壓範圍應用的效率。此外，輸出電壓12 V和24 V二合一設計可避免現場施工的LED模組發生搭配性問題。另一方面，冷凍櫃展示照明用LED燈串使用24 V電源系統，並以並聯方式實現大面積照明，每個LED模組都內藏一電阻器或線性穩壓器來調節LED電流，以維持穩定的光通量輸出。本研究提出一新型具兩段調光之高效率LED驅動器設計，利用非穩定複振器和圖騰柱驅動器整合的脈寬調變調光電路，並採用單一調光線來實現20%調光，降低冷凍櫃LED照明的耗電量和系統組裝的複雜度。

The objective of this dissertation is to design a new high-efficiency dimmable LED drivers for large-area LED lighting applications to improve system efficacy. LED modules for signage backlighting are parallel in a 12 V or 24 V power system to achieve large-area display illumination. Each LED module has a built-in resistor or linear regulator to regulate the LED current to maintain a stable luminous flux output. This study proposes a new high-efficiency LED driver design with a hybrid rectifier, using the secondary LED current detection of the half-bridge LLC-type series resonant converter to achieve automatic conversion between full-bridge rectifier and half-wave rectifier to improve the efficiency of wide output voltage range applications. Moreover, the two-in-one design of 12 V and 24 V output voltage avoids the matching problem of LED modules in field construction. On the other hand, LED light bars for refrigerated display lighting are parallel in a 24 V power system to achieve large-area lighting. Each LED light bar has a built-in resistor or linear regulator to regulate the LED current to maintain a stable luminous flux output. This study proposes a new high-efficiency LED driver design with bi-level dimming that use an astable multivibrator and totem pole gate driver integraded pulse width modulation dimming circuit, and using a single dimming wire to achieve 20% dimming, reducing the power consumption and system assembly complexity of refrigerated display lighting.

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