常州工学院毕业设计论文 摘要

针对晶体管串联提供稳压电源的具有体积很大而且笨重的工频变压器，体积

和重量都很大的滤波器，占用较大空间，质量较大，效率较低不适用现在电子技术的发展的的缺点，提出了发展新型电源的意见。为了能够适用电力电子越小型化、轻型化的要求，开关电源随之出现。开关电源采用功率半导体作为开关元件，通过周期性通断开关，控制开关元件的占空来调整输出电压，因为开关电源是直接对电网电压进行整流、滤波、调整，不需要电源变压器，工作频率高，滤波电容小、电感小，所以体积相对较小，而且开关电源的功耗较低，对电网的适用能力强，所以开关电源的应用逐渐取代了传统的电源。开关电源的发展促使了电力电子器件朝着轻薄化的发展，开关电源有多种拓扑结构，选择合适的拓扑结构，合适的器件，是设计开关电源的重中之重。

关键字：开关电源；拓扑结构；稳压管；芯片

I

常州工学院毕业设计论文 Abstract

Series

to provide power supply for the transistor with large and bulky

size-frequency transformers, size and weight are great filters, occupy a larger space, the quality of larger, less efficient not apply to the development of electronic technology is now thepaper proposed the development of new power views.In order to apply more power electronics miniaturization and light requirements, switching power supply soon.Switching power supply using power semiconductor devices as switches, through periodic on-off switch, control switch to adjust the air component of the total output voltage, because switching power supply is directly rectified mains voltage, filter, adjustment, no power transformer, high frequency, filter capacitance, inductance is small, so relatively small size, low power consumption and switching power supply on the application of strong power, so switch power gradually replaced the traditional power.Switching power supply prompted the development of power electronic devices toward the light of the development of a variety of switching power supply topology, select the appropriate topology, the appropriate device, is the top priority of switching power supply design.

Keywords：switch power supply；Topology Structure；stabilivolt；Chip

II

常州工学院毕业设计论文 目录

摘要................................................................................................................................ I Abstract ......................................................................................................................... II 目录.............................................................................................................................. III 第一章 绪论.................................................................................................................. 1

1.1 开关电源的产生.............................................................................................. 1

1.1.1 开关电源产生的时代背景.................................................................. 1 1.1.2 开关电源的产生.................................................................................. 1 1.2 开关电源的发展.............................................................................................. 2

1.2.1 我国的开关电源的发展........................................................................ 2 1.2.2 国外开关电源的发展............................................................................ 3 1.2.3 开关电源发展的整体趋势.................................................................... 4 1.3 开关电源的现状.............................................................................................. 5 本章小结................................................................................................................. 5 第二章 开关电源的几种结构...................................................................................... 6

2.1 boost电路 ......................................................................................................... 6

2.1.1boost电路图 ............................................................................................ 6 2.1.3 boost电路特点 ....................................................................................... 7 2.2 buck电路 .......................................................................................................... 8

2.2.1 buck电路图 ............................................................................................ 8 2.2.2 buck电路的工作原理 ............................................................................ 8 2.2.3 buck电路的特点 .................................................................................... 9 2.3 正激电路........................................................................................................ 10

2.3.1 正激电路图.......................................................................................... 10 2.3.2 正激电路的工作原理.......................................................................... 10 2.3.3 正激电路的特点.................................................................................. 12 2.4 反激电路........................................................................................................ 12

2.4.1 反激电路图.......................................................................................... 12 2.4.2 反激电路的工作原理.......................................................................... 12 2.4.3 反激电路的特点.................................................................................. 14 本章小结............................................................................................................... 14 第三章 电路的选择.................................................................................................... 15

3.1 电路拓扑类型的选择.................................................................................... 15

3.1.1电路拓扑结构选择要注意的问题....................................................... 15 3.1.2拓扑结构的对比分析........................................................................... 15 3.2 反激变压器的主要方程................................................................................ 17 3.3 变压器磁芯的选择和匝数的计算................................................................ 18

3.3.1 变压器的磁芯的选择.......................................................................... 18 3.3.2 变压器的匝数的计算.......................................................................... 20 3.3.3 磁芯等的各种损耗.............................................................................. 21 本章小结............................................................................................................... 23 第四章 开关电源中的芯片介绍................................................................................ 24

III

常州工学院毕业设计论文 4.1 TOP250 ........................................................................................................... 24

4.1.1 TOP250的管脚图及其作用 ................................................................ 24 4.1.2 TOP250的特色 .................................................................................... 25 4.2 pc817 ............................................................................................................ 29

4.2.1 pc817的管脚图和封装图 .................................................................... 29 4.2.2 pc817 的特点和应用 ........................................................................... 29 4.2.3 pc817 最大绝对值和观点特性 ........................................................... 29 4.3肖特基二极管................................................................................................. 31

4.3.1 肖特基二极管的外观及结构.............................................................. 31 4.3.2 肖特基二极管的工作原理.................................................................. 32 4.3.3 肖特基二极管的检测.......................................................................... 33 本章小结............................................................................................................... 33 第五章 硬件电路........................................................................................................ 34

5.1 交流-直流电路 .............................................................................................. 34

5.1.1交流-直流电路图 ................................................................................. 34 5.1.2 交流-直流的波形图 ............................................................................ 34 5.1.3 整流电路的工作原理.......................................................................... 35 5.2 直流-直流的电路 .......................................................................................... 37

5.2.1 直流-直流的电路图 ............................................................................ 37 5.2.2 直流-直流的分析 ................................................................................ 37 5.3 测试分析........................................................................................................ 39

5.3.1 负载特性测试...................................................................................... 39

5.3.1.1 负载特性测试电路图................................................................ 39 5.3.1.2 负载特性测试所用器材............................................................ 39 5.3.1.3 负载特性测试数据.................................................................... 40 5.3.1.4 负载特性测试数据分析............................................................ 41 5.3.2 纹波特性测试...................................................................................... 41

5.3.2.1 纹波特性测试电路图................................................................ 41 5.3.2.2 纹波特性测试所用器材............................................................ 42 5.3.2.3 纹波特性测试数据.................................................................... 42 5.3.2.4 纹波特性测试数据分析............................................................ 43 5.3.3 交流特性测试...................................................................................... 43

5.3.3.1 交流特性测试电路图................................................................ 43 5.3.3.2 交流特性测试器材.................................................................... 44 5.3.3.3 交流特性测试数据.................................................................... 44 5.3.3.4 交流特性测试数据分析............................................................ 45

本章小结............................................................................................................... 45 总结.............................................................................................................................. 46 致谢.............................................................................................................................. 47 参考资料...................................................................................................................... 48 附录1 元件清单......................................................................................................... 50 附录2 总电路图......................................................................................................... 51 附录3 实物................................................................................................................. 52

IV