LED檯燈亮度調整之探討

Discussion of LED Table Lamp Brightness Adjustments

莊高宜(Kao-Yi Chuang)

指導教授 ： 謝振榆

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2013年)

摘要

面臨全球能源危機和日益嚴重的氣候暖化問題，找尋新的節能方式已經成為全球普遍關注的話題。發光二極體（LED）為一種固態光源，是繼白熾燈、螢光燈、高強度放電燈（如高壓鈉燈和金鹵燈）之後的新光源。由於發光二極體之發光效率大幅提昇，且具有壽命長、小型化、以及驅動容易等優點，逐漸取代傳統光源，成為最新一代照明系統之主流光源。又在眾多的照明系統中，檯燈是我們常使用的照明光源之ㄧ，作為工作或閱讀照明的輔助光源，因此日後勢必也陸續改用LED取代現今檯燈的光源。所以本研究以檯燈為研究方向，進行光源發光二極體（LED）在外接5V直流電源或USB供電條件下，探討類比和脈寬調變兩種方式定電流調光之功率與亮度的效能。希望藉由其量測結果可以建議或提供相關所需研究之參考。
所以本論文提出兩種調光電路結構，從分析模擬數據可知，類比調光電路的效率較低但價格較便宜，價格差在濾波反馳元件，其中電感價格為0.08990美元，二極體價格為0.06858美元，二者合計價差0.15848美元。在調光效率表現上，兩者恰好成相反的走勢；類比調光時，調得越亮效率越高，而脈寬調變調光時，調得越亮效率越低。在此就調光50%時之功率做為功耗差額的比較，類比耗電2.5瓦，脈寬調變耗電1.85瓦，兩者相差0.65瓦。如果每天晚上約使用3小時，以年度計算，假設一年使用1000小時，也就是一年有0.65度電費的價差，如果每度電費以0.1美元計算，則一年電費差0.065美元，那麼在成本價差0.15848美元的狀況下，需要 0.15848/0.065=2.438美元，也就是約兩年半的時間。
由於LED的壽命至少在一萬小時以上，但一般對檯燈產品的保固都在三年以下，若是重度使用者，應該選擇以脈寬調變電路所製造的產品，而輕度使用者不妨選擇較便宜的類比調光產品較為合算，且發光均勻，不會有高頻脈動直流的干擾與輻射。

關鍵字

類比 ； 脈寬調變 ； 定電流 ； 調光 ； 功率亮度

並列摘要

Facing the global energy crisis and the growing climate warming problem, and to find new ways of energy saving has become a topic of global concern. The light-emitting diode (LED) is a solid-state light source, following the incandescent, fluorescent, high intensity discharge lamps (such as high-pressure sodium lamps and metal halide lamps) light sources. Significantly enhancing the luminous efficiency, and having the advantages of long life, miniaturization, and easily driving, LED lighting gradually replaces the traditional light sources, and becomes the mainstream light source for the latest generation of lighting systems. In many lighting systems, table lamps have become the most auxiliary lighting source while working or reading, the future is bound to gradually replace today's lamp light sources as LED. Therefore, this study is based on a table lamp of LED in an external 5V DC power supply or a USB powered condition to explore the performance of both analog and pulse-width modulation constant current dimming power efficiency and brightness. I hope the measurement results can suggest or provide the necessary research reference.
This paper presents two dimming circuit structure, from simulation data that shows analog dimming circuit efficiency is low but the price is cheaper, the price difference in filtering flyback element. The inductance price of 0.08990 U.S. dollars, diodes prices of 0.06858 U.S. dollars, both the total spread of 0.15848 U.S. dollars. In dimming efficiency performance, both exactly are opposite trend; analog dimming, the higher the efficiency of adjusting the more bright, and the pulse-width modulation circuit, adjusting lower of the light that efficiency are more bright. This dimming when 50% of the power as the difference between the power comparison, analog power consumption of 2.5 watts and pulse-width modulation power of 1.85 watts , a difference of 0.65 watts. If every night for approximately three hours, calculation of one year, assuming 1000 hours a year, which is the year tariff spread of 0.65 degrees per kWh electricity 0.1 U.S. dollars, year electricity charge difference of 0.065 U.S. dollars, the cost differences less than 0.15848 U.S. dollars, need 0.15848/0.065, = 2.438 U.S. dollars, that is using to two and a half years of time.
LED be used life time more than ten thousand hours, but the general table lamp warranty in the following three years, if a heavy user, may should select the products are manufactured to the pulse-width modulation circuit, while the mild users may to choose the cheaper analog dimming products are cost-effective, and luminous uniformity, there will be no interference with the radiation of high frequency pulsating DC.

並列關鍵字

Analog ； Pulse Width Modulation ； Constant Current Dimming ； Power ； Brightness

參考文獻

[2]黃秉鈞，2006，”高亮度LED 照明時代來臨推動能源節約”，台

可靠度研究”, 國立中山大學光電所畢業博論.

化事業股份有限公司網站資料，

[5]陳珮真，2001，“電熱分離之LED投射光源模組開發”，虎尾科技

[9]S. Nakamura, M. Senoh, and T. Mukai,1993, “High-oiwer