单管正激式开关稳压电源的设计-吴位信材料.doc

本科学生毕业论文 单管正激式开关稳压电源的设计 系部名称： 电气与信息工程学院 专业班级： 电气11-1班 学生姓名： 吴位信 指导教师： 葛洪军 职 称： 副教授 黑 龙 江 工 程 学 院 二○一五年六月 The Graduation Thesis for Bachelors Degree Design of the single pipe is shock type switch regulated power supply Candidate： Wu Wieixin Specialty：Construction Machinery Class：11-1 Supervisor：Associate Prof. Ge Hongjun Heilongjiang Institute of Technology 2015-06·Harbin 摘 要 开关稳压电源有多种类型，其中正激式开关电源因其电路简单可靠，抗过载能力强，所需要的元器件较少，容易集成，不易饱和且能够提供多路隔离输出等优点而被广泛应用于中、小功率电源领域。为了保证电路的稳定可靠，本次设计采用的是隔离型电路，其中以单端正激型变换器作为主电路，其主要由高频变压器与开关管构成，主要功能是处理电能。本文分析了PWM脉宽调制芯片UC3844构成开关电源的整体结构电路，并以UC3844作为主芯片控制功率MOS管P60NF06的导通与截止，而UC3844的启动电压由三端稳压器LM7818输出提供，采样反馈电路以TL431和光电耦合器PC817为核心，而输入滤波电路和输出整流滤波电路主要由电容构成，且对输入干扰和输出纹波电压有了很好的消除作用，使系统更加的稳定可靠，从而完成了单管正激式开关电源的设计。 关键词：开关电源，正激型变换器，PMW，UC3844  ABSTRACT With the rapid development of power electronic technology, the application of switching power supply is also more and more widely. There are different types of switching power supply, which is the IP switch power supply because of its circuit is simple, reliable, strong overload capacity, the required components less, ease of integration, not easily saturated and can offer the advantages of multiple output isolation and widely applied in the medium and small power sources. This design is given priority to with single correct type excitation converter circuit, mainly consists of high frequency transformer and switch tube, its main function is to deal with electricity. This paper analyzes the PWM pulse width modulation chip UC3844 constitute integral circuit structure and working principle of switch power supply, and by UC3844 as the main control chip control switch tube P60NF06 conduction and deadline, sampling feedback circuit TL431 and photoelectric coupler PC817 as the core, and the input filter circuit and output rectifier filter circuit is mainly composed of capacitor,