【正文】 I 摘 要 本篇論文介紹的筆記本電源設配器的設計。是一種開關穩(wěn)壓電源，系統(tǒng)首先由工頻電網(wǎng)接入 220V， 50HZ 的交流電壓，這個交流電壓經(jīng)過一級整流、濾波電路處理后送入由兩個開關晶體管組成的逆變電路進行轉換，晶體管管通過開通或切斷電流通路將直流電壓變成一個 100 kHz的交流電壓，交流電壓送入高頻變壓器進行降壓，降壓后輸出的交流電再經(jīng)過高頻整流、濾波后輸出一個 16V 的直流電壓，輸出端反饋回的電壓，電流信號經(jīng)過控制芯片 TL494的處理后，由 8腳和 11腳輸出寬度可調的脈沖信號給開關管，控制開關管的脈沖信號，從而達到恒 流，穩(wěn)壓輸出的目的。文中第 1章主要是對設計的總體介紹和題目所涉及到的背景和意義等。第 2 章開始主要敘述的是本次設計中所用到的芯片資料，包括內部結構、管腳功能典型應用電路。第 3章開始詳細的介紹了各部分電路的設計過程包括電路的設計，元件的選擇，參數(shù)的計算等等。 關鍵詞： 電源適配器 ， 變壓器 ， PWM 控制電路 ， 高頻濾波 II 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 , the exchanges electric voltage with 50 HZ, this exchanges electric voltage sends to go into after pass by a class mutate, 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 bee the direct current electric voltage an exchanges electric voltage of 100 kHz, municating the electric voltage sends into high frequency transformer to carry on declining to press, the output39。s alternate current passes by again high frequency to output a direct current electric voltage of 16V after mutate, the filter after declining to press, outputting electric voltage that carry feedback39。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 output39。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 ponent, the calculation etc. of the parameter. Key Words: Adapter ， Transformer ， PWM control circuit ， high frequency of filter, III 目錄 摘 要 ....................................................................................................................... I Abstract .................................................................................................................. II 1． 緒論 .............................................................................................................. １ 什么是電源適配器 ............................................................................... １ 電源適配器的發(fā)展與趨勢 .................................................................... １ 半橋開關穩(wěn) 壓電源 ............................................................................... ３ 目前正在克服的困難 ........................................................................... ４ 開關電源的發(fā)展方向 ............................................................................ ５ 2．系統(tǒng)的總體概述及部分元件介紹 ................................................................ ６ 系統(tǒng)的功能及工作過程 ...................................................................... ６ TL494 芯片簡介 ................................................................................. ７ TL494 芯片工作原理 ............................................................... ８ 3． 系統(tǒng)元件設計 .......................................................................................... １０ 輸入整流與濾波電路 ..................................................................... １０ 一次整流電路 .................................................................... １０ 一次濾波部分 .................................................................... １１ 變壓器的設計與計算 .................................................................... １２ 開關變壓器的設計 ............................................................ １３ 導線線徑的選取 ................................................................ １５ 線圈繞制與絕緣 ................................................................ １５ 功率開關管的選擇 ......................................................................... １６ 輸出二極管 VD2 的選用 ............................................................... １６ PWM 控制電路的設計 .................................................................. １８ PWM 控制模式的基本原理 ................................................. １８ PWM 控制電路原理圖 ......................................................... ２０ 控制芯片 TL494 ................................................................. ２０ 逆變電路的設計 ............................................................................. ２２ 驅動電路的設計 ............................................................................. ２５ 電路簡介 ............................................................................ ２６ 工作過程 ............................................................................ ２６ 二極管 D5 的作用 ........................................