Automatic Photo Power Control System Design for RGB LED Color Temperature Research

[[abstract]]LED發光亮度與驅動電流成正比，所以當驅動電流維持固定則發光亮度即可穩定。溫度會影響LED的發光功率，當溫度上升則發光功率就會降低，所以發光功率會隨著溫度變化而變化，所以必須用控制電路改善。 在這篇論文中,我們以自動電功率控制系統為基本架構加上溫度補償機制完成自動光功率控制系統設計。自動光功率控制系統已經經由實驗證實在環境溫度-30℃~85℃時可以維持光功率的穩定。再將自動光功率控制系統應用於色溫控制，色溫隨溫度變動與穩定的情況下探討演色性的變化趨勢。 關鍵詞：自動電功率控制電路;自動光功率控制電路;色溫控制;發光二極體。[[abstract]]The brightness of the Light Emitting Diode is proportional to the forward current. The constant forward current of LED provides a stable brightness. Temperature is an important factor of LED optical power. The photo-power decreases with increasing temperature. Therefore, an advanced control scheme is proposed. In this paper, a scheme of Automatic Photo-Power Control system (APC) based on Automatic Electrical Power Control system (AEC) with temperature compensation is proposed. It is confirmed that optical power is stable with the range of temperature from -30℃ to 85℃ in the system. Furthermore, the discussion of color rendering index (CRI) variation under the automatic color temperature control is also verified. Key words: Automatic Electrical Power Control (AEC);Automatic Photo Power Control (APC);Color temperature control;Light Emitting Diode[[note]]碩