高效可調(diào)光LED驅(qū)動(dòng)電源研制

應(yīng)用物理學(xué)論文編號:WLX106  字?jǐn)?shù):11632,頁數(shù):22

 
目  錄
中文摘要 i
英文摘要 ii
目  錄 iii
第1章  緒 論 1
1.1  研究動(dòng)機(jī)和目的 1
1.2  研究背景及意義 1
1.2.1  研究背景 1
1.2.2  研究的意義 2
1.3  論文內(nèi)容概述 2
第2章  LED簡介 3
2.1  LED基本特性 3
2.1.1  LED發(fā)光原理 3
2.1.2  LED的特性曲線 3
2.2  白光LED特性 4
2.2.1  白光LED特性概述 4
2.2.2  白光LED光學(xué)特性 4
第3章  大功率LED驅(qū)動(dòng)電源硬件制作 5
3.1  驅(qū)動(dòng)電源參數(shù)設(shè)定 5
3.2  驅(qū)動(dòng)芯片的選擇 5
3.2.1  驅(qū)動(dòng)芯片的分類 5
3.2.2  驅(qū)動(dòng)芯片的選取 6
3.3  兩種芯片設(shè)計(jì)的驅(qū)動(dòng)電源比較 6
3.3.1  LM3402驅(qū)動(dòng)電源設(shè)計(jì) 6
3.3.2  LM2575驅(qū)動(dòng)電源設(shè)計(jì) 8
3.3.3  高效LM2575驅(qū)動(dòng)電源設(shè)計(jì) 9
第4章  驅(qū)動(dòng)電源性能測試與分析 11
4.1  測試儀器 11
4.2  恒流性能測試 11
4.3  可調(diào)光性能測試 12
4.3.1  光通量可調(diào)分析 12
4.3.2  LED驅(qū)動(dòng)電流與光通量的關(guān)系 12
4.4  LED串聯(lián)個(gè)數(shù)與電源效率關(guān)系 13
第5章  結(jié)束語 14
致  謝 15
參考文獻(xiàn) 16
附錄  測試數(shù)據(jù)表 17

摘    要
 LED作為一種固體光源，因其具有光效高、壽命長、穩(wěn)定性好等諸多優(yōu)良的特性，應(yīng)用前景十分廣闊。本課題針對當(dāng)今LED驅(qū)動(dòng)電源功耗大、體積大的不足，利用LM2575 DC/DC降壓芯片設(shè)計(jì)了一種體積小、效率高、性能穩(wěn)定、價(jià)格便宜的PWM驅(qū)動(dòng)電源，用以恒流驅(qū)動(dòng)大功率（1W）白光LED，并可通過調(diào)節(jié)外部電位器改變輸出電流，實(shí)現(xiàn)大功率LED光強(qiáng)可調(diào)的目的。從測試數(shù)據(jù)可以看出該驅(qū)動(dòng)電源效率可達(dá)85%；輸入電壓在11V到38V之間變化時(shí)，LED驅(qū)動(dòng)電流及其發(fā)光強(qiáng)度保持恒定，實(shí)現(xiàn)恒流驅(qū)動(dòng)的目的；當(dāng)改變外圍電位器阻值使總阻值在0.6Ω到3Ω之間改變時(shí)，LED的驅(qū)動(dòng)電流在350mA到70mA之間變化，調(diào)節(jié)LED發(fā)光強(qiáng)度，達(dá)到光強(qiáng)可調(diào)的目的。因該驅(qū)動(dòng)電源設(shè)計(jì)參數(shù)符合電動(dòng)車的要求，可將該驅(qū)動(dòng)電源應(yīng)用在如今仍使用電珠照明的電動(dòng)車上，用LED取代電珠照明以提高電動(dòng)車用電效率。
關(guān)鍵詞：大功率LED  恒流驅(qū)動(dòng)  可調(diào)光  DC/DC轉(zhuǎn)換器

Abstract
 As a solid light source, LED has an enormous application prospect because of its advantages, such as high efficiency, long life, stability and so on. Due to the disadvantages of the current Power Supply which has high power consumption and large volume, a PWM power supply based on LM2575 DC/DC step-down chip has been designed with the characteristics of small volume, high efficiency, steady performance, low cost. It is used to drive powerful (1W) white LED by constant current which can be adjusted by regulating external potentiometer, and the light intensity is also changeable. According to the test data, we can learn that the efficiency of the power supply can reach to 85%, and when the input voltage is changed from 11V to 38V, the LED’s drive current and luminous intensity keep constant to achieve the purpose of constant current drive. When the total resistance is changed from 0.6Ω to 3Ω by adjusting the external potentiometer, the LED’s drive current varied from 350mA to 70mA and the luminous intensity is changeable. Because the designed parameters of this power supply meet the requirements of electric motor car, the device can be applied to the electric motor car which still use lamp bulb to light. Using LED instead of lamp bulb to light, the power efficiency of electric motor car will be improved.
Keywords: Powerful LED; Constant current driver; Adjustable intensity; DC/DC converter