LED照明电路设计(本科毕业设计书).doc

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North China Institute of Water Conservancy and Hydroelectric Power
毕业设计
题目 LED照明电路设计

学院信息工程学院
专业通信工程
姓名
学号
指导教师
2011年 5月 12 日
LED照明电路设计
摘要
发光二极管(Light Emitting Diode,LED)是21世纪最具发展前景的一种新型固态光源。LED的迅速发展及广泛应用,将引发照明领域的一场革命。 LED具有环保性好,使用寿命长,单色性好,色彩鲜艳丰富,体积小,重量轻,响应速度快,发光效率高,能量消耗低等优点。
目前,LED在景观照明等一些应用中大多利用交流市电电源供电。LED的发展和应用的目标是取代白炽灯等传统光源,LED应用照明领域的能源仍然主要来自于电网。我国的市电电源是220V/50HZ,国际通用交流线路为85~265V,50/60HZ。由于LED要求在直流低电压下工作,采用市电电源供电,则需要通过适当的电路拓扑,也就是LED驱动电路将其转换为符合LED工作要求的直流电源。
现在设计驱动电路的一般思路是先将220V的高压电通过一个变压器,使其变成低电压的交流电。在通过一个桥式整流电路,把交流电转换成直流电。在整流桥后并上两电容,一个是平滑电容,滤除剩余的交流电,一个是高频旁路电容,滤除高频分量。这样就留下所需的低压直流电。后面可根据设计的需要,连上不同的芯片,实现所需要的功能。如恒压,恒流,反馈,温度补偿等。

关键词:发光二级管,照明,直流电,低电压,驱动电路
Abstract
Summary led (Light Emitting Diode,LED) is the 21st century with the most development prospects of a new type of solid state light source. Rapid development and wide application of LED, lighting a revolution in the field will be thrown. LED has a good environmental protection, long service life, well monochrome, color rich, small volume, light weight, fast response, high luminous efficiency, low energy consumption.
At present, most LED landscape lighting in some applications, such as using AC mains power supply. Development and application of LED's goal is to replace traditional light sources such as incandescent lamps, LED lighting energy is still e from the power grid in the field of the application. Mains power supply is 220V/50HZ in China, international AC line to 85~265V,50/60HZ. Because LED requires working in DC low-voltage, power supply, you need to go through the appropriate circuit topology, which LED drive circuit converts with the LED work requirements of DC power supply.
Now drive circuit design of the general idea is the first high voltage of 220V through a transformer, making it into a low-voltage AC. In a bridge rectifier circuits, to convert AC to DC. After the bridge rectifier and two capacitors, a smoothing capacitor, filter out the rest of