| 摘要: | 本論文闡述如何設計一脈波型自動光功率控制電路應用於發光二極體，在環境溫度改變的情況下，依舊可以維持穩定的定光功率輸出。相較其他方式，本論文最大的優點為不需要外接的光二極體（PhotoDiode）感測發光二極體之光功率變化，而是直接使用電路上的方式補償發光二極體光功率的改變。而脈波型的驅動方式，較一般連續型之推動方式，更方便於後級的應用。而在發光二極體以脈波型式驅動上，驅動電流值針對紅、綠以及藍色之發光二極體，可以達到穩定的62.5mA、37.5mA、37.5mA導通電流值。脈波型電路導通頻率最高可至200Hz，且無相位延遲之問題。無需光二極體之自動光功率控制電路可以維持從0℃至70℃之穩定光功率輸出，而紅、綠以及藍色之發光二極體其穩定光功率分別為8.4mW、5.2mW以及9.9mW。在相關應用上，使用脈波驅動三種光原色後，在紅、綠、藍色之Duty Cycle值分別為1：3：1時，可獲得最高的CRI值78.789。在紅、綠、藍色之Duty Cycle值分別為2：3：1時，可獲得最接近6500K色溫之6534K，且在此時CRI值為52.299。 This paper elaborates how to design a Pulse Mode Driver Circuit for Light Emitting Diode with Automatic Photo-Power Control, which can still maintain the stability of optical power in the circumstances of ambient temperature changes. Compare to other modes; the most important advantage of this paper is that it doesn’t need PhotoDiode from externals to induct the changes of LED optical power, while it can straightly make use from circuit to compensate the changes of LED optical power,. And compare to general successive driving modes, the driving mode based on Pulse Mode makes the applications of last stage lots more handier. According to the LED driven by Pulse Mode, driver current of red, green, and blue LED can respectively reach stable numbers 62.5mA, 37.5mA, and 37.5mA. The frequency of Pulse Mode circuit can reach, the highest number, 200Hz, but without the problems of phase delay. When the circuit is controlled by the Automatic Power Control without of PhotoDiode, it can maintain the stability of optical power in the temperature range of 0℃ to 70℃. And the stable optical power of red, green , and blue PhotoDiode are respectively 8.4mW, 5.2mW, and 9.9mW。About related applications; after practicing the pulse to drive RGB, when the number of Duty Cycle is 1:3:1, the highest CRI number 78.789 will be reached. And upon the Duty Cycle number are respectively 2:3:1, the closest color temperature to 6500K, 6534K can be acquired, meanwhile, the CRI number will be 52.299. |
