LED驱动电源设计.doc

重庆大学本科学生毕业设计(论文)
LED驱动电源设计
学生: 周灏
学号:
指导教师: 唐治德
专业:电气工程与自动化
重庆大学电气工程学院
二O一一年六月
Graduation Design(Thesis) of Chongqing University
Design of Driver Power for LED
Undergraduate: Zhou Hao
Supervisor: Prof. Tang Zhide
Major: Electric Engineering & Automation
School of Electric Engineering
Chongqing University
June 2011
摘要
该文针对LED驱动电源的设计需要,先简述了LED及其驱动电源的基本情况,包括BUCK电路及其控制电路的工作原理、稳定性分析等。然后以UC3843电流控制芯片和BUCK电路为基础,设计出了一款车用LED驱动电源,并通过仿真实验,对电路进行了检验。文中详细介绍了UC4843的使用方法、该驱动电源的设计步骤以及具体参数计算。
这款驱动电路工作在12V直流电压下,以BUCK电路为主电路,采用峰值电流控制模式,按照PWM调制方法,对两颗串联的LED进行供电,实现了恒流输出、欠压保护、过载保护、空载保护、斜坡补偿等功能,并且在仿真实验中均体现出了各部分的作用。这款LED驱动电源工作稳定,抗干扰能力强,输入范围广,输出电流平稳;通过简单改变供电方式,此电路还能用于不同领域。
另外该文还对仿真实验结果进行了较为详细的分析,对补偿斜坡尾部上翘、电流采样电阻的至畸作用进行了讨论。
关键词:驱动电源,峰值电流控制,PWM, LED,UC3843
ABSTRACT
This article for the purpose of the design needs of LED driver power, firstly summarizing briefly the basic information of LED and its driver power, including BUCK circuit as well as its working principles of control circuit, the stability analysis etc. Then based on the UC3843 electric current control-chip and BUCK circuit, a vehicle LED driver power has been designed, and its electric circuit has been tested through the simulation experiments. This article describes the usages of the UC4843, the design process of the driver circuit and the specific parameter calculation in detail.
This driver power works at 12V DC voltage, with BUCK circuit as the main circuit, adopting the control mode of peak current, in accordance with the PWM modulation method, providing power to two series connections of LED, bringing about the functions of under-voltage protection, overload protection, idle-load protection, pensation, and reflecting their respective functions in the simulation experiments. This LED driver power works stably, with strong anti-interference ability, wide input range; stable output current; by changing the way of power supply, the circuit can also be used in different fields.
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