LED節(jié)能燈驅(qū)動(dòng)電源設(shè)計(jì)



目錄

摘要 4

Abstract 5

1引言 6

2概 述 6

2.1 LED的發(fā)明 6

2.2 LED工作原理 7

2.2.1、LED發(fā)光機(jī)理 7

2.2.2、LED發(fā)光效率 7

2.2.3、LED電氣特性 7

2.2.4、LED光學(xué)特性 7

2.2.5、LED熱學(xué)特性 8

2.2.6、LED壽命 8

3 LED照明應(yīng)用的國(guó)內(nèi)外現(xiàn)狀 8

3.1國(guó)內(nèi)外發(fā)展現(xiàn)狀： 8

3.2全球 LED產(chǎn)業(yè)現(xiàn)狀與發(fā)展趨勢(shì) 9

3.3國(guó)內(nèi)外LED產(chǎn)業(yè)發(fā)展現(xiàn)狀與態(tài)勢(shì)呈現(xiàn)出的特點(diǎn) 10

4 LED的驅(qū)動(dòng)方式簡(jiǎn)介及特點(diǎn) 12

4.1 阻容降壓式原理及電路 12

4.1.1 電路原理 12

4.1.2 設(shè)計(jì)原則 13

4.1.3設(shè)計(jì)舉例 13

4.2 開(kāi)關(guān)式 13

4.2.1、開(kāi)關(guān)式穩(wěn)壓電源的基本工作原理 13

4.2.2、開(kāi)關(guān)式穩(wěn)壓電源的原理電路 14

4.2.3開(kāi)關(guān)電源的種類 15

4.3 PFC電路原理 19

4.3.1 PFC的定義 19

4.3.2 PFC 的分類 20

4.3.3 PFC主電路原理圖 20

5 高效率恒流PWM開(kāi)關(guān)電源 21

5.1 UC3842的主要性能特點(diǎn) 21

5．2 UC3842工作原理 22

5.3 PWM 22

5.3.1 DC/DC轉(zhuǎn)換器 23

5.3.2 電流型PWM 23

5.4.1 啟動(dòng)電路 25

5.4.3 反饋電路 26

5.4.4 整流濾波電路 27

5.4.5 并聯(lián)整流二極管減小尖峰電壓 27

6 總結(jié) 28

主要參考文獻(xiàn) 29

致謝 31




摘要

本文概述了LED的發(fā)明、工作原理、LED照明應(yīng)用的國(guó)內(nèi)外現(xiàn)狀，對(duì)LED的三種驅(qū)動(dòng)方式：阻容降壓式驅(qū)動(dòng)、恒壓、恒流式開(kāi)關(guān)驅(qū)動(dòng)進(jìn)行了較詳細(xì)的討論，并且用UC3842設(shè)計(jì)了一款LED高效率恒流PWM開(kāi)關(guān)電源, UC3842 采用固定工作頻率脈沖寬度可控調(diào)制方式，共有8 個(gè)引腳，UC3842是開(kāi)關(guān)電源用電流控制方式的脈寬調(diào)制集成電路。該集成電路主要特點(diǎn)有內(nèi)含欠電壓鎖定電路，低起動(dòng)電流，穩(wěn)定的內(nèi)部基準(zhǔn)電壓源，大電流推挽輸出，工作頻率可到 500kHz。本設(shè)計(jì)采用UC3842設(shè)計(jì)一款PWM開(kāi)關(guān)電源，該電源同時(shí)具有恒壓﹑橫流驅(qū)動(dòng)的特點(diǎn)。效率可達(dá)80%以上，非常適合LED照明應(yīng)用，充分發(fā)揮LED的發(fā)光效率高，壽命長(zhǎng)等特點(diǎn)。


關(guān)鍵字：效率  開(kāi)關(guān)  PFC   PWM   驅(qū)動(dòng)


 




Abstract

This paper summarizes the principle of invention, LED lighting, LED to the application situation at home and abroad, the three drivers LED resistance and capacitance step-down type: driver, constant pressure, flow switch drive discussed in detail, and the design of a UC3842 LED efficiency constant-current PWM switch power, using fixed frequency UC3842 pulse width modulation patterns, controllable consists of eight feet, LED by current UC3842 is switch power control PWM integrated circuits. The main features are embedded integrated circuits, low voltage circuit owe the lock, stable internal starting current, voltage source current benchmark push-pull output, working frequency to 500kHz. This design UC3842 a PWM switch power, the power and the constant pressure, transverse drive features. Efficiency can reach more than 80%, very suitable for LED lighting applications, full of leds luminous efficiency, long life, etc.




Key words: efficiency   switch    PFC    PWM    drive