【正文】 ................................................................. 錯(cuò)誤 !未定義書簽。 signal。 PWM。 本設(shè)計(jì)是基于單片機(jī)控制的 PWM信號(hào)輸出 系統(tǒng)，系統(tǒng)以 AT89C52單片機(jī)為核心， 采用SPWM 軟件生成法中對(duì)稱規(guī)則采樣法 ，用 擴(kuò)展 按鍵中斷方式 輸入有關(guān)控制信號(hào)及參數(shù)，可以實(shí)現(xiàn) 頻率、占空比、 輸出時(shí)間可調(diào)的直流斬波 PWM信號(hào)和頻率、調(diào)幅比、輸出時(shí)間可調(diào)的 SPWM信號(hào)， 并在 LCD1602 上實(shí)時(shí)設(shè)置參數(shù)及輸出狀態(tài)監(jiān)視 。然后 采用 C語言編程實(shí)現(xiàn)了系統(tǒng)功能，完成設(shè)計(jì)目標(biāo)。首先對(duì) 系統(tǒng)結(jié)構(gòu) 和 PWM軟件算法 進(jìn)行了研究和分析，包括對(duì)各種 PWM 產(chǎn)生方法的對(duì)比分析和對(duì)稱規(guī)則采樣法的仔細(xì)研究以及系統(tǒng)的功能分 區(qū)和總體結(jié)構(gòu)。 PWM技術(shù)結(jié)合了電力電子技術(shù)、計(jì)算機(jī)技術(shù)、現(xiàn)代控制理論，具有抗干擾性強(qiáng)、 效率高、可靠性好等顯著 優(yōu)點(diǎn)，已經(jīng)在交流逆變、開關(guān)電源等領(lǐng)域得到廣泛應(yīng)用。摘要 隨著電力電子技術(shù)的飛速發(fā)展， PWM技術(shù)應(yīng)用越來越廣泛。同時(shí) PWM 技術(shù)本身也發(fā)展迅速，各種新理論層出不窮。 本文在研究 PWM 技術(shù)當(dāng)前發(fā)展?fàn)顩r基礎(chǔ)上，設(shè)計(jì)了一種基于單片機(jī)的 PWM 信號(hào)輸出系統(tǒng)。在總體設(shè)計(jì)完成后又設(shè)計(jì)了硬件電路 各個(gè)單元模塊。最后對(duì)設(shè)計(jì)的系統(tǒng)進(jìn)行了計(jì)算機(jī)仿真。 關(guān)鍵詞 ：單片機(jī)； PWM； SPWM；信號(hào) ；規(guī)則采樣法 ABSTARCT As the developing of power electronic technology, PWM technology has applying to more and more field. At the same time, PWM technology itself has taken a great progress, lots of new theory has emerged. PWM technology takes advantages of power electronic, puter technology, and modern control theory, has strong ability of antiinterference, and is more efficiency, reliable. It has applied to vast field ,such as AC converter, DC chopper. This paper firstly, analysis the situation of PWM technology’ development, then, designed a PWM signal output system based on SCM. At the beginning, we study the soft algorithm of PWM, including parison and analysis of several PWM algorithm and deep analysis of regularsampling. We also designed the system structure. Following , hardware and software is designed. Every hardware module is designed with the puter, and the software is written in C language. At last, we take a simulation. The system is based on AT89C52. It use buttons to input parameters. It can output single polar PWM signals. The signal’s frequency, dutycycle, output time can be changed. What’s more, all information is showed in a LCD1602, so that it is easier to municated with the system. Index terms: SCM。 SPWM。 regularsampling 目 錄 1 緒論 .....................................................................................................................................................1 PWM 的背景、應(yīng)用及發(fā)展趨勢(shì) .............................................................................................................. 1 PWM 原理 .................................................................................................................................................. 1 本文的主要工作 ....................................................................................................................................... 2 2 系統(tǒng)方案設(shè)計(jì) ......................................................................................................................................3 系統(tǒng) PWM 算法 ......................................................................................................................................... 3 等面積 法 ............................................................................................................................................. 3 硬件調(diào)制法 ......................................................................................................................................... 3 軟件生成法 ......................................................................................................................................... 3 系統(tǒng)結(jié)構(gòu) ................................................................................................................................................... 5 涉及元器件簡介 ........................................................................................................................................ 5 AT89C52 介紹 ...................................................................................................................................... 5 LCD1602 簡介 ...................................................................................................................................... 8 仿真工具介紹 .......................................................................................................................................... 9 Protues 簡介 ....................................................................................................................................... 9 Keil uVision2 簡介 ............................................................................................................................. 11 3 硬件電路設(shè)計(jì) ..................................................................................................................................... 13 電源 .......................................................................................................................................................... 13 單片機(jī)復(fù)位電路 ...................................................................................................................................... 14 單片機(jī)時(shí)鐘電路 ...................................................................................................................................... 14 按鍵中斷 .................................................................................................................................................. 15 顯示電路 .................................................................................................................................................. 16 輸出電路 .................................................................................................................................................. 17 SPWM 測(cè)試電路 ...................................................................................................................................... 17 4 軟件設(shè)計(jì) ............................................................................................................................................ 19 軟件總流程 .............................................................................................................................................. 19 直流斬波 PWM 軟件計(jì)算法 ...............................