發光二極體數位調光技術普遍以脈波寬度調變(Pulse Width Modulation, PWM)為主，藉由變換電流之工作週期供應給發光二極體來做調光；但在效率上還是以類比調光較優良。本論文旨在研究用於發光二極體之均流可調光驅動器，綜合數位與類比之調光架構方式，利用降壓式調光電路供應一穩定且可自行調整之電流值，其可因應發光二極體之順向電壓需求做改變，再藉由時序開關控制發光二極體電流的工作週期，透過這兩者相輔相成，調控流經發光二極體電流之平均值，以達到調光之目的。
本研究前級使用單級返馳式功率因數修正器提供一高功因且穩定之電壓源供給降壓式調光電路輸入所需，透過降壓式調光電路作為發光二極體之功率需求端，其可因應發光二極體所需之順向電壓而做調整，並利用時序開關控制電路使輸出之並接發光二極體模組處於動態輪序導通的模式，在此發光環境下，其因應人眼視覺暫留之特性可視發光二極體模組為同步發光，只需一組功率輸出分別對模組進行電壓、電流之調變，即可完成類同步調光，使多組並接之發光二極體模組，無須使用額外功率級的擴增電路也可因應在不同之顆數、順向電壓、色溫之功率需求條件，達到均流控制而穩定調光之目的。
論文中針對單級返馳式功率因數修正器、降壓式轉換器及時序導通電路的動作原理及各項技術做詳細分析與討論，以SIMPLIS進行模擬分析，並實作一台60W高功因可調光之發光二極體驅動器實作測量驗證其架構之可行性。

The pulse width modulation, PWM, has been used commonly for LED lighting control with digital control technique. Nevertheless, analogue control provides better dimming characteristics and power efficiency. The thesis is devoted to develop and design a novel constant current driver used for light emitting diodes (LEDs) which also enables dimming feature based on persistence of human vision. By connecting multiple LED light modules in parallel, LED light modules can be triggered alternately and dimmed via constant current control technique. The pri-stage of the circuit consists of a single-stage fly-back converter, stable with high power factor performance, and a buck-converter which feed adequate power to the load. With the asynchronous alternative-switching control of the buck-converter and the persistence phenomenon of human vision, multiple loads are enabled to be connected in parallel and triggered alternatively by automatically detecting the forward voltage of the loads which in turn adjust the output currents to the loads without additional circuitries.
The thesis proposed a novel driving algorithm, a single-stage fly-back converter with power factor correction and buck converter with alternative-switching control circuit, to provide a cheaper and simpler circuitry with flicker free performance. The dimming features are achieved according to the different load demand, such as different numbers of LEDs used, different forward voltages rating or different color temperatures of LEDs, without changing the circuitry configuration, which guarantees a fast and efficient way to power up the LED modules. We used commercial software, SIMPLIS, to simulate and design a 60W high power factor LED driver to identify the feasibility of the proposed methods. The results show that the proposed novel driving technique is practical and valuable for LED lighting applications.

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