高效率交流發光二極體於SPICE之模擬分析

Abstract

本論文研究交流電(Alternating current 簡稱AC)驅動之交流發光二極體(Alternating current Light Emitting Diode簡稱AC LED)，並以惠斯頓橋式二極體電路(Wheatstone bridge Diode circuit)，本文將從傳統照明光源之發光特性切入探討，介紹交流發光二極體(Alternating Current LED; AC LED)與傳統直流發光二極體(Direct Current LED; DC LED)在操作上的差異電特性比較分析。一般照明光源中除了單顆DC LED元件之散熱有較高的困難度與應用特定區塊，並且透過一轉換驅動元件。往往在DC LED壽命達到前，外部的驅動轉換元件壽命就已經達到了。造成整體模組無形中壽命縮短。本篇透過SPICE的電路模擬軟體來，模擬不同面積及顆數下的最大發光效率。並且將SPICE模擬軟體，透過Matlab軟體的控制，來各種橋式二極體電路下的最佳組合，並計算各種功率值，光通量，效率等。 透過 Matlab軟體來編輯電路的各種組合，在第一部份的論文主要先以固定總顆數下去改變整體晶片的大小去比較，各種光輸出以及各種效率的提昇，接下來並以固定總面積下，去改變顆數的組合，以及透過外部限流電阻來控制Wheatstone橋式二極體電路整體的工作電流。

The thesis investigates a design of high-efficiency GaN-based alternating-current light-emitting diodes (AC-LEDs). The novel design is demonstrated by using a Wheatstone bridge (WB) circuit. In the traditional GaN-based LEDs, it is only operated in the direct current (DC). Therefore, the rectifier becomes an essential electro component for the general lighting system of the LEDs to transform the alternating current applied from the city power company into DC. However, the life of the converter is usually shorter than the DC LEDs, and the whole module is damaged. In the thesis, the WB circuit is implemented by GaN-based LEDs, and it can be driven by the AC source. In order to improve the radiation efficiency of AC LED, the best arrangement of the WB LED circuit is adjusted and simulated by the SPICE tool. There are two major parts to be discussed in the thesis. One is to investigate the relationship of the optical power output and the LED area. The other is to survey the relationship of the external resistor and the current. The above subjects are achieved by using the SPICE and Matlab tool, and it can provide a complete and quick analysis.