发布时间 : 星期日 文章工科大学毕业论文-笔记本电源适配器更新完毕开始阅读
摘 要
本篇论文介绍的笔记本电源设配器的设计。是一种开关稳压电源，系统首先由工频电网接入220V，50HZ的交流电压，这个交流电压经过一级整流、滤波电路处理后送入由两个开关晶体管组成的逆变电路进行转换，晶体管管通过开通或切断电流通路将直流电压变成一个100 kHz的交流电压，交流电压送入高频变压器进行降压，降压后输出的交流电再经过高频整流、滤波后输出一个16V的直流电压，输出端反馈回的电压，电流信号经过控制芯片TL494的处理后，由8脚和11脚输出宽度可调的脉冲信号给开关管，控制开关管的脉冲信号，从而达到恒流，稳压输出的目的。文中第1章主要是对设计的总体介绍和题目所涉及到的背景和意义等。第2章开始主要叙述的是本次设计中所用到的芯片资料，包括内部结构、管脚功能典型应用电路。第3章开始详细的介绍了各部分电路的设计过程包括电路的设计，元件的选择，参数的计算等等。
关键词： 电源适配器 ，变压器 ，PWM控制电路，高频滤波
I
Abstract
A design of Adapter is introduced in this text. Being a kind of switch is steady to voltage power supply, the system is first connected into a 220 V by the work frequency of current net, the exchanges electric voltage with 50 HZ, this exchanges electric voltage sends to go into after pass by a class commutate, the filter the electric circuit processing is constitute by two switch transistors of go against and change the electric circuit carry on a conversion, field the effect tube pass to break through or cut off the electric current thoroughfare to become the direct current electric voltage an exchanges electric voltage of 100 kHz, communicating the electric voltage sends into high frequency transformer to carry on declining to press, the output's alternate current passes by again high frequency to output a direct current electric voltage of 16V after commutate, the filter after declining to press, outputting electric voltage that carry feedback's return, the electric current signal is outputted adjustable pulse signal of width by 8 feet and 11 feet to take care of to the switch through the processing of the control chip TL494, controlling a switch a tube of pulse signal, attain invariableness to flow thus, steady voltage the output's purpose. The safe work that still established to lead to voltage protection electric circuit in the switch power supply electric circuit with the electric voltage, electric current led to flow protection electric circuit to examine an importation and output to carry in order to for the system in addition provided an emollient guarantee. Chapter 1 in text mainly is to total introduction and topic of design involve to of the background and meaning Chapter 2 beginning mainly what to describe is in this design use of chip data, include internal structure, the pin function typical model application electric circuit. Chapter 3 beginning introduced each design process of parts of electric circuits to include the design of the electric circuit in detail, the choice of the component, the calculation etc. of the parameter.
Key Words: Adapter ，Transformer ，PWM control circuit ，high frequency
of filter,
II
目录
摘 要 ....................................................................................................................... I Abstract .................................................................................................................. II
1． 绪论 .............................................................................................................. １
1.1 什么是电源适配器 ............................................................................... １ 1.2电源适配器的发展与趋势 .................................................................... １ 1.3 半桥开关稳压电源 ............................................................................... ３ 1.4 目前正在克服的困难 ........................................................................... ４ 1.5开关电源的发展方向 ............................................................................ ５ 2．系统的总体概述及部分元件介绍 ................................................................ ６
2.1 系统的功能及工作过程 ...................................................................... ６ 2.2 TL494芯片简介 ................................................................................. ７
2.2.1 TL494芯片工作原理 ............................................................... ８
3． 系统元件设计 .......................................................................................... １０
3.1 输入整流与滤波电路 ..................................................................... １０
3.1.1 一次整流电路 .................................................................... １０ 3.1.2 一次滤波部分 .................................................................... １１ 3.2 变压器的设计与计算 .................................................................... １２
3.2.1 开关变压器的设计 ............................................................ １３ 3.2.2 导线线径的选取 ................................................................ １５ 3.2.3 线圈绕制与绝缘 ................................................................ １５ 3.3 功率开关管的选择 ......................................................................... １６ 3.4 输出二极管VD2的选用 ............................................................... １６ 3.5 PWM控制电路的设计 .................................................................. １８
3.5.1 PWM控制模式的基本原理 ................................................. １８ 3.5.2 PWM控制电路原理图 ......................................................... ２０ 3.5.3 控制芯片TL494 ................................................................. ２０ 3.6 逆变电路的设计 ............................................................................. ２２ 3.7 驱动电路的设计 ............................................................................. ２５
3.7.1 电路简介 ............................................................................ ２６ 3.7.2 工作过程 ............................................................................ ２６ 3.7.3 二极管D5的作用 .............................................................. ２６ 3.8 输出整流滤波电路的设计 ............................................................. ２７
3.8.1 输出滤波器的设计 ............................................................ ２７ 3.8.2 输出整流电路的结构 ........................................................ ２７
III
结论 .................................................................................................................. ２９ 致谢 .................................................................................................................. ３０ 参考文献 .......................................................................................................... ３０ 附录 .................................................................................................................. ３０
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