单片机专业毕业设计论文_ 高保真音响设计制作
单片机智能音响控制设计
单片机智能音响控制设计一、引言智能音响的出现，为人们的娱乐生活带来了便利和乐趣。
然而，如何实现对智能音响的高效控制成为了一个重要的问题。
本文将介绍一种利用单片机进行智能音响控制的设计方案。
二、背景现代智能音响一般具备音量调节、播放控制等功能，但是用户需要通过遥控器或者手机应用进行操作，操作体验不够便捷。
因此，设计一种基于单片机的智能音响控制系统可提高用户体验，实现更高效的音响控制。
三、设计方案本设计方案采用基于单片机的智能音响控制系统，主要包含硬件设计和软件设计两个部分。
1. 硬件设计硬件设计主要包括单片机选型、音频输入输出模块和用户交互模块。
1.1 单片机选型可以选择常用的单片机，如Arduino、Raspberry Pi等，根据需求选择适合的单片机型号。
1.2 音频输入输出模块设计一个音频输入模块，用于接收外部音频信号，例如通过麦克风接收用户语音指令。
同时，设计一个音频输出模块，用于将音频信号输出到音响设备进行播放。
1.3 用户交互模块为了实现用户与智能音响的交互，设计一个用户交互模块，例如使用触摸屏、按键等方式接收用户指令，并将指令传递给单片机进行处理。
2. 软件设计软件设计主要包括音频信号处理算法和用户指令处理算法。
2.1 音频信号处理算法设计音频信号处理算法，例如噪声抑制、音频增强等，以提供更好的音质和用户体验。
2.2 用户指令处理算法设计用户指令处理算法，例如语音识别算法，将用户语音指令转化为相应的控制命令，实现音量调节、播放控制等功能。
四、实现与测试在硬件设计完成后，进行硬件的搭建和连接，同时编写相应的软件代码。
在实现完成后，进行系统测试，验证智能音响控制系统的功能和性能。
五、结论本文介绍了一种基于单片机的智能音响控制设计方案。
通过该方案，用户可以通过语音指令或者触摸屏等方式高效控制智能音响，提供更好的音质和用户体验。
六、展望本设计方案只是一个基础模型，未来可以进一步完善，加入更多的功能和特性，例如与智能家居系统的联动、支持更多语音助手等，以满足不断变化的用户需求。
毕业设计(论文)-基于单片机控制的音乐播放器[管理资料]
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单片机音乐播放器设计报告学生：XXX 指导教师：XXX内容摘要：单片机具有体积小、功能强、成本低、应用面广等优点，可以说，智能控制与自动控制的核心就是单片机。
根据要求设计一款音乐播放器，能实现音乐播放的简单功能，同时为了美化，添加了韵律闪烁彩灯，设计时采用Keil软件编程，用protues软件仿真，核心器件采用灵活性高且价格低廉的AT89C51芯片。
设计完成后系统可播放自编歌曲，同时发光二极管随着歌曲韵律闪烁。
关键词：单片机 AT89C51 音乐播放英文标题Abstract: SCM has small, strong function, low cost, application, advantages and intelligent control and automatic control of the core is the microcontroller. According to the requirements of a music player, design of music broadcast can realize simple function, and to beautify, added rhythm flashing lights, design is used when Keil C software programming, with protues software simulation, the core device adopts high flexibility and the price is cheap AT89C51 chip. The design is completed system can play Wrote songs, and leds with songs rhythm flicker.Keywords:SCM Temperature AT89C51 Music broadcast前言:微机原理和接口技术是一门实践性强的学科，不但要求有较高的理论水平，而且还要求有实际的动手能力，其中很多的原量、规则、现象等仅仅靠学习教科书是无法完全掌握的，必须通过实践才能比较直观和深刻的理解。
毕业设计(论文)-基于单片机的mp3播放系统设计[管理资料]
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随着计算机技术，微电子技术和数字信号处理技术的迅速发展，各种消费类电子产品朝着集成化和小型化发展。
特别是随着网络多媒体技术的普及、数字音视频技术的快速发展，以MP3为代表的消费类电子产品广泛的应用在我们的生活中，数字音频技术得到了长足的发展。
MP3全称是动态影像专家压缩标准音频层面3（Moving Picture Experts Group Audio Layer III）。
是当今较流行的一种数字音频编码和有损压缩格式，它设计用来大幅度地降低音频数据量，而对于大多数用户来说重放的音质与最初的不压缩音频相比没有明显的下降。
它是在1991年由位于德国埃尔朗根的研究组织Fraunhofer-Gesellschaft的一组工程师发明和标准化的。
MP3就是一种音频压缩技术，由于这种压缩方式的全称叫MPEG Audio Layer3，所以人们把它简称为MP3。
MP3是利用MPEG Audio Layer 3 的技术，将音乐以1:10 甚至1:12 的压缩率，压缩成容量较小的file。
能够在音质丢失很小的情况下把文件压缩到更小的程度。
而且还非常好的保持了原来的音质。
本课题以基于单片机的MP3数字音频系统的软件设计与实现过程为主要内容，阐述了其相关技术和具体实现流程，其中重点分析了FAT32文件系统在单片机上的移植。
整个系统利用STC公司的单片机12C5A60S2作为系统的中央处理器，采用VLSI公司的VS1003解码芯片作为MP3解码芯片，SD卡作为系统的存储器，LPH7366显示屏作为系统的显示屏。
经过实验测试证明，采用单片机实现的MP3播放系统切实可行，且具有很高的稳定性、实用性和扩展性。
关键词：12C5A60S2 MP3 FAT32 VS1003 SD卡1 前言 (1)设计指标 (1)设计要求 (1)2 文献综述 (1)软件介绍 (1)Protues仿真功能介绍 (1)Keil μVision IDE仿真功能介绍 (2)STC12C5A602S (5)VS1003-MP3/WMA 音频解码器 (5)LPH7366LCD模块 (6)SD存储卡 (7)3 系统硬件设计 (8)系统总体硬件设计 (8)各模块硬件设计 (9)显示模块硬件设计 (9)音频解码模块设计 (9)SD卡模块设计 (10)系统原理图 (11)4 系统设计 (12)模块介绍 (12)主程序模块 (12)显示程序 (12)SD卡程序 (14)音频解码程序 (15)znFAT文件系统程序 (16)程序流程图 (17)主程序流程图 (17)5 测试分析与计算 (18)SD卡兼容性测试 (18)MP3兼容性测试 (19)6 系统的安装与调试 (20)7 创新与特点 (20)8 总结 (20)致谢 (22)参考文献 (23)Abstract (23)附录 1 主程序附录 2 实物图毕业设计成绩评定表1 前言MP3全称是动态影像专家压缩标准音频层面3（Moving Picture Experts Group Audio Layer III）。
高保真音响设计制作论文翻译中文
独立电唱机前置放大器一个高精确度唱机的前置放大器Fred Nachbaur, Dogstar撰写1997年1．介绍最近有非常多关于历史悠久的真空电子管的优点（和缺点）的新闻。
至于这种复古运动多少是基于可论证的理论，多少是建立在发烧友的怀旧情怀和主观印象的基础上，这个问题可能会是一个充满争议的辩论。
我们现在很清晰的是：现在对真空电子管，这种20多年前的，被认为和spats 和top hats一样古老的东西，有相当多的人进行关注。
现在潮流有点倒转的感觉，有许多的生产厂家又为高保真音响爱好者，音乐家以及高保真发烧友们提供电子管装置。
很多情况下，这些都是一些简陋的古老的（或者我们应该说是“最佳的”电路稍微做了些改动，就变成了一个新的创作品。
别的产品提供了新的真空电子管技术的途径，同时添加了我们学到的一些真正的值得的设计。
为什么要使用电子管？这种支持电子管运动的最大争议就是：规格几乎没有什么意义，而最重要的是每个听众的个人主观的听觉才是最重要的。
因此高度主观的描述在这里被运用，取代了最近我们或多或少习惯的技术上的消除混串音干扰。
那个相反的阵营认为数字不会撒谎，并且如果加入了任何的失真你也不能去证明。
两个阵营都很有论据。
我们中很多人都听过这种装置有着引人注目规范，但是被弃之不用因为“太好以至于不真实”，几乎大家都认为这种设备表达的只是一种临床的声音。
同样的，大部分人们都会同意:如果音响设备有电子管在里面的话，就不值得去听。
如果你想感受到真空电子管听起来有多难受的实证，打开案头的那些老的“All-American Five”调幅收音机就可以了。
也许协调这两种观点的一种方法是考虑到音响设备和录音重放设备的差别。
对于音响设备来说，单个机器的频率，波形，和相位失真是对一个Fender 电子管放大器声音的定义。
就像没人会试着用一些规格和失真的数据去定义一个很好的小提琴一样，所以，如果去争论某个35瓦特的电子管放大器超过了12％的总谐波失真度没有，是很片面的。
高保真音箱的设计
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下达任务书、学生收集资料、熟悉毕业设计（论文）课题
总体方案设计
硬件设计
系统调试
编写毕业设计（论文）说明书
教师评阅设计（论文），学生进行总结、准备答辩
2进度安排起止日期工作内容下达任务书学生收集资料熟悉毕业设计论文课题总体方案设计硬件设计系统调试编写毕业设计论文说明书教师评阅设计论文学生进行总结准备答辩毕业设计论文答辩主要参考资料1王辛之
2011届毕业设计课题任务书
系：电气与信息工程系专业：
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高保真音箱的设计
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1设计任务：设计一个具有音量、高音、中音和低音调节的高保真音箱；
[5]孙育才,苏学成.单片微型计算机应用系统设计与实现[M].南京:东南大学出版社,1990.
[6]李朝青.单片机原理及接口技术[M].北京:北京航空航天大学出版社, 2002.
[7]马世界.系统的可靠性设计和故障诊断[J].黑龙江水利科技,2005,33(5):109.
[8]李海.单片机应用系统可靠性技术的探索[J].工业技术,2006(13):40-41.
[9]葛素娟,朱祥贤.单片机应用系统的抗干扰技术[J].重庆科技学院学报,2006,8(4):68-70.
[10]何小艇.电子系统设计[M]. 3版.杭州:浙江大学出版社,2004.
高保真音响设计制作论文开题报告
四、阐述拟选题的目的、意义、要完成的工作和预期结果
1．选题目的：为了能将自己学习的模电知识结合自己平时对音响的兴趣结合在一起，所以我决定结合工科基础和自己的兴趣来做出一个HI-FI高保真功率放大器。来实现理论与实践的结合。
至于我在设计中将用到的集成功放就是NE5532(前置功放)，后级为LM1875。
其中NE5532被认为是“运放之皇”，它的内部为JFET（结型场效应管结构）,声音特点总体来说属于温暖细腻型，驱动力强，但高音略显毛糙，低音偏肥。
NE5532虽然是一个比较旧的运放型号，但现在仍被认为是性价比最高的音响用运放芯片，是属于平民化的一种产品，被用于许多中底档的功放中。该功放技术已经相当成熟。
3．预期结果：做出的电路基本上满足上面我提及的参数，并且接上音源以及扬声器能发出优美的声音。
五、毕业设计所必需的实验、计算、加工等初步计划
本实验所需设备：
1.微机一台以及Protel 99se的软件；
2.低频信号源；
3.示波器；
4.万用表；
2．选题意义：可以让我感觉到我们学习理论知识对我们将来从事的工作起到的重要作用，同时也初步体验到了作为一个技术人员，需要很强的耐心，坚持的性格，才能做出一个令他人，令自己满意的硬件和配套的软件出来。同时，我觉得自己查找资料的过程便是对我本身，作为一个在信息海洋的现代社会生存的人的甄选知识能力的锻炼。同时，我也懂得了许多有关技术制作时涉及到的成本问题，也就是性价比的问题，这点很重要。
我想在我完成了这次毕业设计后，一定会学到很多技术的知识，不过我想不仅仅是技术的知识，应该还会学到一种韧劲，一种精神。
毕业设计(论文)-基于单片机的mp3播放器设计[管理资料]
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摘要在我们的日常生活中，人们会面对许多来自周围环境的压力，而听音乐已经成为普通大众放松自己的方式，MP3播放器则是听音乐必不可少的工具。
以前的音乐播放器有功能单一、系统流畅度低、输出音质差、无法扩展容量、与电脑交换数据时传输缓慢等缺点。
为了提高MP3播放器的质量，满足各类人群需求，特此设计了一个基于单片机的MP3播放器。
本课题主要研究基于单片机的MP3设计，设计以STC12C5A60S2单片机作为主控芯片，同时结合音频解码芯片VS1003、功率放大器、存储电路、SD卡读写模块等外部电路组成音乐播放系统。
能够完成对存储器识别和数据读取，将在存储器中读取的MP3文件或其他音频文件解码并播放流畅的音乐。
关键词：MP3播放器；STC12C5A60S2单片机；VS1003解码器AbstractIn our daily life, people face a lot of pressure from the surrounding environment, and listening to music has become a way of the general public to relax,the MP3 player is the tool to listening music. Once upon a time the music player has a single function, low system fluency, output quality is poor, cannot expand capacity, exchange data transmission shortcomings such as slow with computers. In order to improve the quality of the MP3 player, meet the needs of all kinds of people, we designed a MP3 player based on single chip microcomputer.This topic finishes the software design of the music player based on the 51 microcontroller，In combination with audio decoding chip VS1003,power amplifier,storage circuit and the SD card reader module composition a music playback system. The system is able to complete the recognition and data memory read,read the files in the memory and play music fluently.Keywords:MP3 player; STC12C5A60S2 MCU; VS1003 decoder目录1 绪论 (1)课题背景 (1)课题意义 (2)课题研究内容 (2)2 主要元器件介绍 (3)STC12C5A60S2单片机简介 (3)VS1003(MP3/WMA音频编解码器) (3)VS1003概述 (3)VS1003特性 (4)VS1003芯片LQFP-48和BGA-49Ball封装的引脚分配 (4)SD卡读写模块 (6)SD卡读写模块概述 (6)技术规格 (6)引脚分配 (7)3 系统硬件设计 (9)系统硬件设计综述 (9)按键控制电路 (9)SD卡电路 (10)VS1003电路 (10)4 系统软件设计 (12)编程软件介绍 (12)Keil软件介绍 (12)Keil使用方法 (12)程序语言介绍 (15)C语言 (15)语言特点 (15)C语言与汇编语言对比 (16)系统软件设计综述 (17)VS1003模块的MP3文件播放程序设计 (20)系统性能分析 (21)5硬件测试 (22)结论 (23)致谢 (24)参考文献 (25)附录A 英文原文 (25)附录B 汉语翻译 (27)附录C 源程序 (28)附录D 元件清单 (44)附录E 电路图 (45)附录F 实物图 (47)1 绪论课题背景德国人Brandenburg在20世纪80年代进入顶尖的研究机构Fraunhofer Institute for Integrated Circuit，组成了MP3研发小组，并开始着手研发MP3。
基于单片机的音乐播放器设计毕业论文
图书分类号：密级：毕业设计(论文) 基于单片机的MP3播放器设计学生汤明学院名称信电工程学院专业名称电子信息工程指导教师豹2012年5月10日摘要因为单片机编写的MP3播放器具有执行效率高、频率输出稳定、易于修改、高可靠性、高性价比、低电压、低功耗等,使单片机近几年得到迅猛发展和大围推广,广泛应用于工业控制系统、数据采集系统、智能化仪器仪表、及通讯设备、日常消费类产品、玩具等[1]。
利用单片机设计的MP3播放器具有硬件电路简单，软件运行可靠等特点。
本文介绍了一种以 AT89S52 单片机为控制核心的MP3。
该设计采用2*16个点阵液晶模块LCD1602作为显示界面，蜂鸣器作为发声元件，并利用定时器进行中断控制。
本文分析了基于单片机的MP3播放器的工作原理，详细介绍了MP3播放器的功能及其硬件设计和软件设计的方法，给出了基于MCS-51单片机的MP3播放器的具体实现方案并重点讲述了其硬件实现与软件编写，实现了单片机MP3播放器对音乐的演奏。
关键词：MP3播放器；AT89S52；LCD1602目录摘要 (I)1绪论 (1)2设计综述 (2)2.1单片机工作原理 (2)2.1.1 单片机概述 (2)2.1.2 单片机的应用领域及发展趋势 (2)2.2 单片机产生音调的方法 (3)2.3 KEIL开发系统 (4)2.4 PROTEUS的操作 (8)3硬件设计 (9)3.1总体方案设计 (9)3.2 单片机最小系统电路 (9)3.2.1 AT89S52芯片性能介绍 (9)3.2.2 电源电路 (13)3.2.3 时钟振荡电路 (13)3.3 键盘扫描模块 (14)3.4 显示模块 (15)3.5 播放模块 (16)4 系统软件设计 (18)4.1编程原理及流程图 (18)5 调试与仿真结果 (22)5.1 软件调试 (22)5.1.1 测试LED显示模块 (22)5.1.2 测试键盘控制模块 (23)5.1.3 测试P3.0口输出 (23)5.2 调试中遇到的问题及解决 (24)5.3 仿真结果 (25)结束语 (26)致 (27)参考文献 (28)附录 (28)附录1 源程序 (29)1绪论几千年来，各种乐器的发声无一不是依靠琴弦、簧片、哨片引起管柱振动而作为声源的。
基于单片机的音乐器设计
毕业设计(论文)专业班级学生姓名学号课题基于单片机的音乐器设计指导教师摘要目前市场上有很多种音乐芯片或音乐模块，可以直接产生各种曲子。
但是这种模块价格比较贵，性价比不高。
对于一些仅需要产生简单的音符或简短曲子的场合，例如智能玩具、电子贺卡等，可以使用单片机配合简单的蜂鸣器就能产生需要的音乐效果，这种方法充分发挥了单片机的优势。
本设计中，用一块AT89C52单片机给蜂鸣器不同的音频脉冲来产生不同的音调，实现演奏歌曲的功能。
同时，通过按键电路来控制歌曲的播放，并在LCD1602上显示歌曲信息。
关键词：音乐；单片机；蜂鸣器；按键；LCD1602AbstractThere are many kinds of music chips or music modules on the market at present, which can directly produce a variety of music. But these modules are expensive and low cost performance. For some only needs to generate simple notes or short tune occasions, such as intelligent toys, electronic greeting cards, the microcontroller can be used with a simple buzzer can produce the required music effect, this method makes full use of the advantages of MCU.In this design, using a AT89C52 chip to the buzzer different audio pulse to produce different tones, realize the function of play the song. At the same time, through the key circuit to control the songs, songs and display information in the LCD1602.Key words: music；MCU；buzzer；key；LCD1602目录摘要 (I)Abstract (I)1绪论 (1)1.1课题背景与意义 (1)1.2国内外研究状况 (1)1.3论文研究内容概述 (2)2硬件电路设计 (2)2.1硬件电路结构图 (2)2.2单片机模块 (3)2.2.1单片机的引脚功能 (3)2.2.2定时器 (5)2.2.3中断 (5)2.3单片机最小系统 (6)2.3.1时钟电路 (6)2.3.2复位电路 (7)2.4发声模块 (7)2.4.1蜂鸣器 (7)2.4.2驱动电路 (8)2.5按键模块 (9)2.6显示模块 (10)3软件设计 (12)3.1软件开发平台 (12)3.2单片机发音原理 (13)3.2.1音调 (13)3.2.2节拍 (14)3.2.3音符码表的编制 (15)3.3主程序流程图 (17)3.4发声模块程序设计 (18)3.5按键模块程序设计 (20)3.6显示模块程序设计 (23)4硬件仿真 (24)5总结 (26)致谢 (27)参考文献 (28)附录一硬件电路原理图 (29)附录二源程序 (30)附录三英文科技文献翻译 (39)1绪论1.1课题背景与意义随着人类社会的发展，人们对视觉、听觉方面的享受提出了越来越高的要求。
电子音乐播放器的设计和制作毕业设计论文
摘要本文是应用AT89S51单片机原理和控制理论设计音乐演奏控制器的硬件电路，并利用C51单片机语言进行程序设计。
通过控制单片机内部的定时器来产生不同频率的方波，驱动喇叭发出不同音调的音乐，再利用延迟来控制发音时间的长短。
把乐谱转化成相应的定时常数就可以从发音设备中演奏出悦耳动听的音乐。
此外电路中加入了按键可以方便控制音乐的播放，有简单的显示电路和按键对应，可以清楚播放的次序。
这种控制电路结构简单，可靠性高,应用性强；软件程序适应范围广，对于不同的音乐只需要改变相应的定时常数即可。
单片机仿真采用的是keil软件，比较方便。
由于硬件电路的设计简单，所以焊接的时候不容易出错，而且调试方便。
对单片机和音乐爱好者有一定的借鉴价值。
关键词：单片机;控制；音乐播放器AbstractThis is the application AT89S51 microcontroller theory and control theory, music performance controller hardware, and using C51 microcontroller programming language. By controlling the MCU’s internal timer to generate square waves of different frequencies to drive speakers make different musical tones, and then use delay to control the length of pronunciation. The music into the corresponding time constants can be played from the sound equipment out of melodious music. In addition, the circuit can be easily added to the buttons control music playback, a simple display circuit and the corresponding keys, can clearly play order. This control circuit is simple, high reliability and strong applicability; software program to adapt to a wide range of different music just for the appropriate time constant change can be. MCU is used keil software more convenient. As the hardware design is simple, it is not easy to go wrong when welding, and convenient debugging. On the MCU and music lovers have some reference value.Keywords: microcontroller; control;music player;目录摘要 (I)Abstract (II)1绪论 (1)1.1立题背景 (1)1.2音乐与音乐播放器 (1)1.2.1音乐 (1)1.2.2音乐播放器 (2)2硬件的电路设计 (3)2.1单片机的复位电路的设计 (3)2.2显示电路设计 (4)2.2.1 LED基本理论知识 (4)2.2.2发光二极管的检测 (5)2.2.3数码管与单片机的简单接口实验 (6)2.3单片机的振荡电路的设计 (7)2.4 控制电路设计 (9)2.5 LM386音频功率放大器 (9)3软件实现 (10)3.1音乐产生的方法 (10)3.2程序设计流程图 (14)3.3定时器/计数器的选择 (15)3.3.1定时器的选择 (15)3.3.2 89S51定时功能及工作方式选择 (15)3.3.3 计数器 (16)3.4定时器/计数器的控制寄存器 (16)3.5中断 (17)3.5.1定时中断源 (17)3.5.2中断控制 (18)3.5.3中断初始化与中断控制寄存器状态设置 (19)3.6本章小结 (20)4程序的调试及测试 (21)4.1检测有无键按下 (21)4.2程序编译 (21)4.3调试过程 (23)4.3.1软件的调试 (23)4.3.2硬件的调试 (25)4.4本章小结 (26)5结束语 (27)致谢 (28)参考文献 (29)附录A 程序清单 (30)附录B 设计总电路图 (41)附录C 硬件实物 (42)1绪论1.1立题背景随着信息技术革命的深入和计算机技术的飞速发展，单片机的应用越来越广泛，并逐渐发展成为一门关键的技术学科。
基于单片机的音乐盒设计本科毕设论文
2014届本科毕业论文基于单片机的音乐盒设计姓名：张静伟系别：物理与电气信息学院专业：通信工程学号：100313037指导教师：吕广申2014年4月20日目录摘要与关键词 (II)0 引言........................................................................................................................... 错误！未定义书签。
1 整体设计方案........................................................................................................... 错误！未定义书签。
1.1 系统总体结构框图........................................................................................ 错误！未定义书签。
1.2 对音乐盒基本功能介绍................................................................................ 错误！未定义书签。
1.3 系统相关软件介绍........................................................................................ 错误！未定义书签。
2 系统整体硬件介绍................................................................................................... 错误！未定义书签。
2.1 硬件设计总体框图........................................................................................ 错误！未定义书签。
基于单片机的音乐盒设计毕业设计
基于单片机的音乐盒设计毕业设计目录前言 (1)1概述 (2)1.1课题意义 (3)1.2设计方案 (3)1.3研究内容 (3)2 系统总体方案介绍 (3)2.1系统组成框图 (4)2.2音乐盒的功能结构图 (4)2.3主要设计软件介绍 (4)2.3.1 PROTEUS软件简介 (4)2.3.2 KEIL简介 (5)3硬件设计 (6)3.1总体设计框图 (6)3.2各部分硬件设计及其原理 (6)3.2.1 AT89C51简介 (6)3.2.2 LED显示电路设计与原理 (7)3.2.3 时钟振荡电路 (7)3.3硬件电路图及功能 (7)4软件设计 (9)4.1音调、节拍以及编码的确定方法 (8)4.1.1 音调的确定 (9)4.1.2 节拍的确定 (10)4.1.3 编码 (12)4.2软件程序设计 (13)4.2.1 程序流程图及相应代码块 (13)4.2.2 程序源代码（见附录A） (18)5调试 (18)5.1检查硬件连接 (18)5.2检查软件系统 (19)5.3测试结果 (19)5.3.1．总体运行图 (19)5.3.2．花样灯3种花样图 (19)6 结束语 (20)附录................................................................................................. 错误!未定义书签。
参考文献.. (30)概述本设计是以AT89C51芯片的电路为基础，外部加上放音设备，以此来实现音乐演奏控制器的硬件电路，通过软件程序来控制单片机内部的定时器使其演奏出优美动听的音乐。
用户可以按照自己的喜好选择音乐并将其转化成机器码存入单片机的存储器中。
对于不同型号的单片机只需要相应的改变一下地址即可。
该软、硬件系统具有很好的通用性，很高的实际使用价值，为广大的单片机和音乐爱好者提供了很好的借鉴。
1.1 课题意义音乐盒的起源，可追溯至中世纪欧洲文艺复兴时期。
基于单片机的音乐播放器的设计—毕业设计
基于单片机的音乐播放器的设计【摘要】本设计是一个基于AT89C51系列单片机的音乐盒，依据单片机技术原理，通过硬件电路制作以及软件编译，设计制作出一个多功能多功能音乐盒。
该音乐盒主要由按键电路、复位电路、时钟电路以及蜂鸣器组成。
使用两个按键控制音乐盒，一个用来切换歌曲，另一个用来切换8路LED的变化花样，本音乐盒共有两首歌曲，花样灯花样共计3种。
播放歌曲时，蜂鸣器发出某个音调，与之对应的LED亮起。
本设计利用KEIL编程软件对音乐盒源程序进行编程并调试，配合PROTEUS仿真软件对硬件进行仿真调试，节约了设计时间。
【关键字】音乐盒；AT89C51单片机；KEIL；PROTEUS；音调1Music box design based on single chip microcomputer [In this paper]This design is a based on AT89C51 singlechip music box series, based on single chip microcomputer technology principle, through the hardware circuits and software compilation, design to produce a multi-functional multi-purpose music box.This music box is mainly composed of key circuit and reset circuit, clock circuit and a ing two buttons control the music box, a used to switch songs, another to switch 8 LED the change of the pattern, the music box of a total of two songs, lamp designs a total of three kinds of designs.Play songs, buzzer sends a tone, and the matching of LED lights up. This design using the KEIL programming software for music box of source program of programming and debugging, cooperate with the PROTEUS simulation software to simulation and debugging of hardware, save design time.[The keyword] Music box; AT89C51; KEIL; PROTEUS. The tones.2目录毕业设计（论文）任务书 (5)引言 (8)第一章概述 (10)1.1 单片机的发展状况 (10)1.2 课题意义 (12)1.3设计方案 (13)1.4设计内容 (13)第二章方案比较 (14)2.1 方案的提出 (14)2.2方案比较 (17)2.3系统组成框图 (18)2.4音乐盒的功能结构图 (18)2.5 主要设计软件介绍 (19)2.5.1 PROTEUS软件简介 (19)2.5.2 KEIL简介 (20)第三章硬件设计 (21)3.1 设计框图 (21)3.2 各部分硬件设计及其原理 (21)3.2.1 AT89C51单片机 (21)3.1.2 时钟振荡电路 (25)3.1.3 发光二极管工作电路图和原理 (28)3.1.4 硬件电路功能 (29)第四章软件设计 (30)4.1音调、节拍以及编码的确定方法 (30)4.1.1 音调的确定 (30)34.1.2 节拍的确定 (33)4.1.3 编码 (35)4.2 软件程序设计 (37)4.2.1 程序流程图及相应代码块 (37)第五章调试 (44)5.1 检查硬件连接 (44)5.2 检查软件系统 (44)5.3 测试结果 (45)5.3.1．总体运行图 (45)5.3.2 花样灯3种花样图 (46)总结 (47)致谢 (48)参考文献 (49)附件1 原理图 (52)附件2 程序代码 (54)4兰州工业学院毕业设计（论文）任务书电子信息工程学院2014届电子信息工程专业毕业设计（论文）任务书基于单片机的音乐播放器的设计毕业设计（论文）题目课题内容性质软、硬件开发设计/论文课题来源性质教师收集的结合生产实际的课题指导老师职称工作单位及部门联系方式讲师电子信息工程学院一、题目说明（目的和意义）本设计希望通过对常见的电子产品的设计与制作来培养学生的综合运用所学知识，分析和解决实际问题的能力，掌握相关的绘图软件，会运用电子仪器进行电路检测和测试，强化电子技术应用技能训练，为今后开展产品技术开发、设计和制作打下初步基础。
毕业设计论文：基于51单片机的音乐发生器设计
本文是应用MCS-51单片机原理和控制理论技术设计音乐发生器的硬件电路，并利用C语言进行软件开发和程序设计。
通过控制单片机内部的定时器产生不同频率的方波，驱动喇叭发出不同音调的音乐，再利用延迟控制发音时间的长短。
把乐谱转化成相应的定时常数，从而达到从发音设备中演奏出悦耳动听的音乐的效果。
该音乐盒主要由按键电路、复位电路、时钟电路以及蜂鸣器组成。
使用两个按键控制音乐盒，一个用来切换歌曲，另一个用来切换8路LED的变化花样，本音乐盒共有两首歌曲，花样灯花样共计3种。
播放歌曲时，蜂鸣器发出某个音调，与之对应的LED亮起。
本设计利用KEIL编程软件对音乐盒源程序进行编程并调试，配合PROTEUS仿真软件对硬件进行仿真调试，节约了设计时间。
本系统采用C语言进行软件设计。
正文中首先简单描述系统硬件工作原理，且附以系统硬件设计框图，论述了本次毕业设计所应用的各硬件接口技术和各个接口模块的功能及工作过程。
其次阐述了程序的流程和实现过程。
本文撰写的主导思想是软、硬件相结合，以硬件为基础，来进行各功能模块的编写。
关键词单片机；音乐；C语言；STC89C51；KEIL；PROTEUSAbstractIn this paper, The music generator and its hardware circuit is designed by MCS-51 single-chip microcomputer principle and control theory, and the Software development and programming are based on C language programming. According to control the MCU internal timer to produce different frequency Square wave to drive the horn sounds of different tones of music, then use the delay to control the length of time. The music Transformationed into the timing constants corresponding so that the sound equipment can play Melodious music.The music box is mainly composed of keypad circuit, reset circuit, clock circuit and a buzzer. Two buttons are used to control the music box, one to switch songs, another is used to switch the 8 LED pattern, the music box has two songs, a total of 3 kinds of pattern light pattern. While the music is playing, the buzzer sounded a tone, and the corresponding LED lights up. The design of programming the music box and debug source code using KEIL programming software, and to save the design time the PROTEUS simulation software is used to simulate the hardware debugging.The system uses C language for software design. Firstly, in the text describes the working principle of the system hardware, and attached to the system block diagram of hardware design to discusse the function andworking process of the graduation design and the application of the hardware interface technology and the interface module. Secondly, expound the procedures and processes to achieve process. The main idea of this writing is a combination of software and hardware, on the base of hardware, write to each function module.Key wordsSinglechip; music; C language; STC89C51; KEIL; PROTEUS目录前言.................................. 错误!未定义书签。
AVR单片机的高音质WAV播放器设计
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高保真音响设计制作论文资料-翻译原文
Standalone Phono Pre-ampA HIGH-PRECISION PHONO PREAMPLIFIERby Fred Nachbaur, Dogstar 1997,1: INTRODUCTIONThere has been much press lately about the merits (and drawbacks) of the venerable vacuum tube. How much of this retro movement is based in demonstrable principles, and how much is rooted in nostalgia or subjectivity is a debate that could fill volumes.What is clear is that there is considerable renewed interest in vacuum tubes, a technology that even two decades ago was considered as obsolete as spats and top hats. Now the trend is reversing, and a number of manufacturers are again supplying tube gear for audiophiles, musicians and hobbyists. In many cases, these are simply vintage circuits in new packaging. Other products offer new approaches to vacuum tube technology, adding what we've learned in the meantime to come up with some truly noteworthy designs. The project described here fits into the latter category.Why use tubes anyway?The central argument for the pro-tube movement is that specs can be almost meaningless, and that what counts is how it sounds to the individual listener. Highly subjective descriptions are therefore used, instead of the techno-babble we've more-or-less gotten used to in recent times. The opposite camp claims that numbers don't lie, and that you can't improve something by adding distortion of any kind.Both camps have valid points. Most of us have heard expensive gear with spectacular specifications, but were left cold by the "too good to be true," almost clinical sound of such equipment. Similarly, most people will agree that just because something has tubes in it doesn't make it worth listening to. Turn on one of those old "All-American Five" table-top AM radios if you want a striking demonstration of just how bad vacuum tube equipment can sound.Perhaps a way of reconciling the two viewpoints is to consider the distinction between musical equipment, and reproduction equipment. For musical gear, the individual frequency, waveform and phase distortions are part of what defines the sound of, say, a Fender tube amp. Just as no- one would try to define a fine Stradivarius violin with specs and distortion figures, so also it would be specious to argue that a certain tube guitar amp has over 12% THD (total harmonic distortion)at 35 watts.Reproduction equipment, on the other hand, has always been expected to give a perfect rendition of the signal applied to it. Sounds good in principle; if such a thing existed, we should be able to exactly and perfectly reproduce everything from a grundge band to the New York Philharmonic, making the reproductions indistinguishable from the original performances.But therein lies the rub. The overall sound of a stereo system depends so heavily on the room it's in, the speakers, volume level, personal preference, and a host of other fuzzy variables that a perfect reproduction system cannot be said to exist even in this day and age, and probably never will. Add the fact that most if not all recordings are electronically sweetened to some degree to make them "sound good" (as opposed to being an exact copy of the performance), and arguments for the clinical reproduction approach lose credibility.Carried to extremes, an "ideal" reproduction system wouldn't even have any controls, except perhaps for selecting inputs. If you think about it, personal preference is the only reason why stereos have volume controls, equalizers, and other adjustments to let us customize the sound to suit our very individual ears and brains.It might be best to view the reproduction gear as a continuation of the same process that started with the construction of the instruments used in the performance. What we ultimately hear is the sum total effect of everything from that original instrument design, to the way it is played by the artist, through the entire recording, mixing and distribution process, to the gear we use to play it, and how we've set its controls.There is, therefore, a considerable difference in design approach between the "instrument" and "reproduction" categories. An earlier design ("The Real McTube") documented a vacuum tube pre-amplifier for use as an adjunct to electric instruments. The design approach was largely empirical, and the emphasis was on highlighting the unique distortion characteristics of the vacuum tube. This article explores the reproduction aspect; the design approach was quite mathematical and precise, and the emphasis is on controlling the characteristics of the vacuum tube.Vinyl vs. CDSimilar arguments are ongoing regarding vinyl records vs. compact discs. The CD camp points at the CD's accuracy, definition, and clarity, while vinyl loversbemoan the CD's lack of warmth and claim that conventional records sound more "natural."This project gives you the opportunity to explore these subjective and controversial debates, letting your own ears be the judge. You may find that there are some recordings that sounds better through the tube pre-amp, and others that benefit from the improved definition (whatever that is, technically speaking) that good solid-state gear can offer.2: DESIGN PHILOSOPHYThe design philosophy was to improve on "vintage" tube designs by incorporating refinements normally only associated with solid-state gear. Prime among these is the use of differential input stages, in which the inverting input is used strictly for feedback. Another is the use of direct coupling between stages, a technique once **mon in oscilloscopes, but rare in audio gear. The resulting circuits are thus closely related to the operational amplifier, and used in a similar fashion.In addition to the quasi-opamp idea, some other design concepts used in theproject are:Use of readily available parts wherever possible. For this reason, tube types 12AX7A and 12AT7A were employed.Direct coupling was used in crucial parts of the circuitry. More about this later.Flexibility in use was a prime consideration. While this articles details the use of this circuit design as a magnetic (RIAA) and ceramic phono pre-amplifier, there is virtually no limit to the number of possible applications with suitable modification of the feedback networks.A Word About Negative FeedbackIt is perhaps an unfortunate accident of history that the term "negative feedback" was used to describe the linearization technique of applying a portion of the output signal back to the input, in opposite phase to the applied signal. It gives the impression to audiophiles with enough knowledge to be dangerous that "negative" feedback must somehow be a "bad" thing. I've seen diatribes against the evils of negative feedback, yet in the same breath such critics extol the virtues of "ultra-linear output transformers." The joke is that such transformers achieve this linearization by applying local negative feedback to the screen grids!Perhaps a better moniker for "negative feedback" would be "**pensation" orsomething on that order. Consider the following characteristics ofwell-designed negative feedback systems:A: Precise control over closed-loop gain and minimization of gain drift with component aging.B: Considerable reduction in distortion and noise introduced within a given gain block.C: Reduction of effective series output resistance.D: Precise control and stabilization of frequency characteristics. Extensionof high-frequency response where needed.E: Reduces or eliminates the need for **ponent matching3: HOW IT WORKSThe sections that follow step through the principles of operation of this design. Since it is quite different from traditional designs, I suggest that you follow through this at least once. If the "fine points" are over your head, don't worry about it; hopefully enough of the information will stick to give you at least a working understanding of the circuit.There are in-line illustrations of the schematic, repeated as necessary. (If you have caching turned on in your browser, you'll only have to actually download the images once.) These "Figures" (schematics) are shown here in reduced size. Click on the image to enlarge it, preferably by right-clicking and opening the image in a new window. Full-size, printable versions are also available in the Resources section. It is highly recommended that you print out these files and have the diagrams at hand as you study this document, especially if you plan on actually building yourself one of these units.Note that in the schematic diagrams, only one channel is shown; the other channel is of course identical. Please note that part numbers refer to the various sections as follows: (We'll be assuming the left channel in this discussion.) 1-99Common parts (power supply, etc.) Also tube designations.100-199Left phono preamp200-299Right phono preamp3-A) HIGH-PRECISION PHONO PREAMPLIFIER: OVERVIEWConsiderable effort was taken to design a preamp that is as clean as possible to satisfy discerning audiophiles, while maintaining a relatively low parts count tosatisfy limited budgets. It should be noted at this point that, while the discussion is in the specific context of an RIAA phono pre-amplifier, this design lends itself well to a wide range of other uses.This "universal preamp module" sports a high gain (about 60 dB) and differentialinput stages that allow for differential input (as for balanced mic preamps) as well as either inverting or non-inverting single-ended applications. Frequency response shaping and gain setting are accomplished using the appropriate feedback networks.The schematic diagram of the phono/mic preamp is shown in Figure 2. If built on a PCB, the phono preamp equalisation is accomplished using a small "daughter" card directly on the main board; if you use the point-to-point wiring approach,these networks can be wired on separate terminal strips for easy modification if necessary.Figure 2 Phono (Magnetic and Ceramic) Preamplifie The main circuit board was designed to be virtually universal in applicability. Small outrigger "feedback cards" are used to customize the response to almost anything you might need. Figure 6 plots gain vs. feedback ratio for the non-inverting configuration as used in the phono/mic preamp. There is an obvious linear relationship, except at high gain. (The "porch" at the low end is due to the "+1" whenusing the non-inverting mode; see below for further details. In the inverting mode, as used in the tone preamp section, the relationship remains linear at low gain settings.)Figure 6 Preamplifier Gain vs. Feedback RatioAs detailed here, the phono preamp is selectable (using a switch) between magnetic (RIAA equalization, high gain), and ceramic (flat response, low gain).See Figure 7, which graphs open-loop response and the two closed-loop phono curves. If you only need one or the other mode options, the switch and the appropriate **ponents can be omitted.Figure 7 Open-loop, Magnetic Phono and Ceramic Phono Response Curves There is no reason why you couldn't adapt this universal preamplifier module for any other gain/**binations, simply by modifying the feedbacknetworks. (Figure 8 gives a few ideas, covered in more detail in Other Preamp Applications.)Other Possible Preamplifier ApplicationsPhono equalisationIn magnetic phono mode, the RIAA curve is achieved by using negative feedback to decrease the gain at higher frequencies, according to the RIAA specification.The result is that the amplifier runs almost open-loop (about 60 dB gain) at 40Hz, and rolls off smoothly to a gain of less than 20 dB at 20 kHz. This means that the "tube sound" caused by even-order distortion will be most pronounced in the bass region, giving it that warmth that is so highly prized by vacuum tube aficionados. At higher frequencies, this distortion is increasingly cancelled out by the negative feedback that sets the gain, keeping the mids from sounding "brassy," and the highs from sounding "splashy" (****plaints about open-loop tube amplifiers).In CD (or ceramic cartridge) mode, response is flat within 0.5 dB over the audio range, and voltage gain is set at 5 (about 14 dB). At this relatively low gain, the circuit is very clean and distortion-free. However, discerning ears will hear a subtle quality of warmth not present insolid-state gear.A 3:1 voltage divider at the input results in an overall system gain of 5 dB. The output level of CD players varies widely among various models, so you can trim this input gain to suit your machine by changing a single input resistor per channel. Similarly, total circuit gain can be changed with a single resistor on the feedback cards.The tube types and their operating points were carefully chosen to minimize power supply requirements, and to maximize tube life. Both channels together draw only about 7 mA from a 400 volt supply. This voltage can be derived from a stand-alone unit as documented in this article, or from a larger supply used to drive a vacuum tube power amp.3-B) PRE-AMP DIFFERENTIAL INPUT STAGESThe preamplifier features a differential input stage, giving us both aninverting and a non-inverting input and affording additional useful andbeneficial features. The following discussion relates directly to thePhono preamps (refer to Figure 2), but applies by extension to otherapplications also.Phono PreamplifierThe appropriate input signal is coupled from the magnetic or ceramicphono input jacks, through switch SW2, to the grid of the first section of V1 (a 12AX7A vacuum tube) via coupling capacitor C101. Since this grid is at a substantial DC voltage above ground, resistor R101 is used to insure that the input is always at DC ground potential. Note that, as far as the input AC signal is concerned, this 100K resistor is effectively in parallel with R102 (also 100K), giving us the 50K input impedance required for most magnetic phono cartridges. The two triode sections of V1 are used as a differential amplifier.Note that the cathodes are tied together, and go to ground via a relatively large shared cathode resistance consisting of R104 and R105. This acts as a rudimentary constant-current source. If the current in either triode increases, a comparable amount of current will be robbed from the other triode. Therefore, if the voltage on the signal input increases (goes more positive), plate current increases and the plate voltage of that triode will drop, while the plate voltage of the other triode increases by about the same amount. However, if the voltage on the feedback input increases, causing an increase in current in that triode, the voltage on the plate of the first triode section willincrease and that of the other triode will decrease.A portion of the cathode resistor voltage drop is sampled by R104, low-pass filtered by R103 and C102, and provides the grid bias for the first section of V1 via R102. An interesting feature of this circuit is that this also sets the bias and operating points for the entire amplifier, as we'll see as we progress through the analysis.Experienced electronicists will be quick to point out that a simple cathode resistor is not an ideal current source. As a result, the "common-mode rejection ratio" (that is, the gain matching of the two inputs) of this circuit is quite low. (A great improvement results by using a pentode as a current source in the differential amplifier cathode circuit, a trick that's used in the driver stage **mon-mode reduction is more critical because we also require balanced outputs.)What we do instead, in the preamp modules, is "cheat the system" and carefully choose the operating points of the two triodes to be different, to help offset the error. Note that, even though there is approximately the same current flowing in the plate circuit of each triode section (about 500 microamperes), the plate voltage on the second section is considerably higher (by about 90 volts) than the plate voltage of the first section. This is because of the lower value of plate resistor R107, as compared to R106. This "trick" assumes that the two sections of the tube are reasonably well-matched, and will furthermore track as the tube ages. Tests with different tubes of varying manufacture and condition have verified that this assumption is indeed valid.3A-2: PREAMPLIFIER OUTPUT STAGEFigure 2 is a schematic diagram of the Hi-Fi Tube Stereo Preamp. Since both channels are identical, only one is shown. Please note that part numbers 100-199 refer to the left channel, and 200-299 refer to the right channel. We'll be assuming the left channel in this discussion.Both channels share a single power supply, shown at the bottom of Figure 2. Transformer T1 steps the 120 volts AC from the power line down to 12.6 volts, to supply the heaters of the three tubes. The center-tapped configuration is used to help reduce hum induced by the heater circuits.Transformer T2 steps the 12.6 volts AC back up to about 110 volts AC for our high-voltage plate supply. Diodes D1-D3 and capacitors C4-C6 are a voltage tripler circuit, providing about 450 volts DC open circuit, or around 380 volts under load. Note that D1, D2, C4 and C5 form the classic positive voltage doubler circuit. On negative half-cycles, C4 is charged through D1.On positive half-cycles, C4 is effectively placed in series with the transformer, and diode D2 transfers this doubled voltage to C5. D3 and C6 are a negative half-wave rectifier/ filter, so the total voltage across C5 and C6 is about three timeswhat would be obtained from a half-wave rectifier. This configuration is used instead of the **mon "cascade" tripler circuit because of its slightly better regulation.The tripled voltage is filtered by the low-pass network formed by R1 and C7. It is further filtered and decoupled by R2/C9 and R3/C8 to form the main supply for each channel. This eliminates any cross-talk between channels due to power supply coupling.Additional decoupling is provided for the critical first stage of each amplifier by onboard filters R117/C103 (left channel) and R217/C203 (right channel), reducing power supply hum injected into these high gain circuits.The output of our differential amplifier is direct-coupled to the grid of the second stage, V2, a 12AT7 dual triode. This tube was chosen over the **mon (and cheaper) 12AU7 because it sports about three times the gain (transconductance), yet is capable of almost the same output drive.The difficulty with direct-coupled vacuum tubes is that the grid of the second stage sits at a substantial voltage above ground (about 200 volts in our circuit). This is why we need a relatively high B+ voltage, since we have to insure that the plate circuit of the second stage has enough headroom. So why bother at all? After all, tube amps have been made for over half a century with good old RC interstage coupling. The answer has to do with dynamic stability as the tubes age. Unlike conventional multi-stage tube amplifiers, our circuit is self-levelling because its DC biasing is in a closed feedback loop.R115 in series with the grid of V2 introduces a high-frequency pole with V2's grid-to-plate capacitance, effectively limiting high-frequency response. This allows us to run the preamp with relatively eavy negative feedback (low gain) without worrying about oscillations caused by phase shifts. You can think of it in op-amp terms as "**pensation".Another reason for using direct coupling is because of the relatively large voltage swings at this point in the circuit. Capacitors (even good ones) can exhibit some non-linearity in capacitance vs. voltage -- a fact that is often overlooked in amplifier design. Direct coupling eliminates this capacitor, and as a bonus gets rid of one more pole in our transfer function that **plicate ourapplication of negative feedback for gain and frequency response control.In order to bias V2's grid at the proper voltage (about -1 volts with respect to cathode), we need a humungous cathode resistor R108. To avoid losing all our AC gain, this resistor is bypassed for AC by capacitor C106.3A-3: PREAMPLIFIER DC FEEDBACKThe rest of our **pletes the DC feedback loop. In case you're wondering about the presence of the three NE-2 neon bulbs in series, let's analyze the circuit without them. The plate of V2 will be sitting at about 315 volts, whereas the grids of V1 are at about 27 volts, or a factor of about 12:1. We could use a 12-to-1 voltage divider,which would give us a DC closed-loop gain of about 13. That is, it would require a 13 volt change at the output to compensate for a 1 volt change at the input.We can easily improve on this considerably. The lowly neon bulb can be viewed as the tube- technology equivalent of the zener diode. That is, the voltage drop across the bulb (typically about 65 volts) is reasonably independent of the current passing through it. The three NE -2's can therefore be viewed as a 200 volt "level shifter," allowing us to use a much lower voltage division ratio (about 4:1) in our DC feedback loop. The result is an almost 3 times improvement in DC operating point stability.The level-shifted and divided output voltage goes through a two-stage low-pass filter consisting of R111, C105, R112 and C104. This strips AC signals from our DC feedback loop, to insure that the amplifier will still have full open-loop AC gain. The resulting DC feedback voltage is applied to the inverting input of our differential amplifier via R113.The junction of R113 and C104 also forms a convenient "AC Ground" point for our signal feedback networks. Let's step through what happens if some change occurs in DC operating point. This change could be caused by tubes and **ponents aging, power supply voltage fluctuations, or input overdrive conditions. Let's assume that the change causes the output voltage to rise, as would be the case as V2's emission decreases. This would cause an increase of bias voltage (more positive) on the grid of V1B (the feedback input), causing that stage to draw more current and increase the voltage on **mon cathode. V1A (our input stage) would therefore draw less current, causing the voltage on its plate (and therefore the grid of V2) to increase. This would cause an increased V2 plate current, resulting in a decrease in plate voltage, tending to buck the original change. See how the overall circuit is self-regulating?Resistor R114 forms the plate load for V2, and C107 couples the output to the tone/line preamp module via the input and tape monitor switches.Capacitor C108 provides another pole of high- frequency attenuation (compensation) to prevent oscillation at low gain. (Before I added this **pensation, the first prototype became a dandy 11 megahertz transmitter at gains lower than about 3!) The original value for this capacitor was 1000 pF, but I've found since then that this can be considerably lower, depending on layout. In the schematic it's shown as 100 pF, if you get oscillation or other instability increase this as necessary.3A-4: PREAMPLIFIER AC FEEDBACKSo far we have a pre-amplifier with an open-loop passband gain of about 60 dB, with 3-dB corners at about 40 Hz and 2 kHz. (See Fig. 7.) While the low-frequency end isn't bad, the high-frequency end is pretty awful. This is partly because of **pensationintentionally introduced by R115 and C108 and partly because of tube electrode and circuit wiring capacitances. Not to worry, our bandwidth automatically increases again when we apply negative feedback, just as it does with solid-**pensated op-amps.Fig. 7: Preamplifier Open-Loop and Phono Gain CurvesAs hinted already, this circuit behaves very much like an operational amplifier (op-amp). But before we get on with designing feedback networks, we'll point out the ways in which it is not like an op-amp:a) Open loop gain, although quite high, cannot be considered infinite as in many solid state op- amp devices.b) The circuit exhibits a large output-to-input voltage offset (on the order of 290 volts). Any AC feedback elements between output and input therefore have to include DC blocking capacitors. The alternative would be level-shifters, which would in my opinion be an **plication (and expense) **mensurate rewards in terms of performance.c) The DC voltage at the feedback input is non-zero (about 27 volts in practise), so again there is a need for DC blocking. The point marked "ACG" (AC Ground) is provided for convenience, acting as a virtual ground for AC, at the same DC voltage as the inverting input.The not-quite-ideal Tube OpampKeeping these restrictions in mind, we can use the formula for the classic non-inverting op-amp to approximate our gain with feedback. Note that the inverting input (-IN) has a 47K resistor (R113) to "AC Ground". This is our "default" value for input resistance to the feedback input. Let's call that resistance Ri, though it can be considerably higher, as needed. The bare-minimum feedback network would consist of just a single resistance (we'll call it Rf ) in series with a DC blocking capacitor between output and -IN. The theoretical gain with feedback would then be:Av = ( Rf / Ri ) + 1For instance, let's compute our gain if we connect a "bare bones"feedback network consisting of a 430K resistor in series with a DC blocking capacitor between "OUT" and "-IN". That is, Rf / Ri = 9.15, so our gain would be 10.15, or about 20 dB.The feedback elements do not have to be pure resistances; the above formula could be generalized to **plex impedances.Av = ( Zf / Zi ) + 1The circuit's actual performance follows this predicted formula very closely, verifying that our gain-matching shortcut described earlier works just fine. See Figure 6 for an actual plot of the prototype. The slight curve at the low end is caused by that "+1" factor in the equation; as Rf / Ri increases, that factor becomes less significant, and the graph approaches a straight-line relationship. However, at gain settings above about 200 (46 dB), the relationship begins to fall apart as we approach the amplifier's open-loop gain. Incidentally, this gain setting is also the practical maximum as regards frequency response; the 3 dB corner at this gain will be on the order of 16 kHz.Figure 6 Preamplifier Gain Vs Feedback Ratio3A-5: PREAMPLIFIER PHONO FEEDBACK NETWORKSCeramic phonoThe feedback network for the Ceramic phono input is little more than our "bare bones" network described above. R118 in series with C109 forms our Zf . R119 is added as a refinement to insure that the negative end of C109 is always held at the DC potential of our feedback input, eliminating the massive pop that would otherwise result when switching modes. Note, however, that it is effectively in parallel with R113, lowering our Ri value to 38.7K. You can verify that our closed-loop gain would therefore be (150/38.7)+1, or about 5 (14 dB).Input resistor R123 attenuates our input signal by a factor of about 3:1, so the overall system gain is a little less than 2 (5 dB).The final element is C110, which introduces a 3 dB corner at about 20 kHz, rolling off ultrasonics that we aren't interested in. (Without this capacitor, the gain is actually flat to well beyond 100 kilohertz! See how feedback got rid of that open-loop corner at 2 kHz?)The magnetic phono feedback is only a little more involved. The straight thin lines in Figure 7 show the theoretical RIAA specification (asymptotes), and the curve。
基于单片机的高保真功放系统设计研究
基于单片机的高保真功放系统设计研究【摘要】随着人们生活水平的提高，对一般的功放听音要求以满足不了人们的生活需求了，现有功率功放普遍存在2大问题：第一是输出信号失真，第二是系统保护问题，主要有：扬声器短路保护、输出信号直流保护。
保护做得不好，很容易烧坏功放输出管和扬声器。
单片机具有强大的测控功能，可以用来解决大功率功放的失真校正和电路保护的问题。
本系统采用单片机HT32芯片作为核心控制器来检测和控制功放系统，是系统各部分实现相应的功能，开机时进行自检和延时等保护，通过蓝牙模块对音频信号进行无线传输，通过数码管调节音量，高音、低音时显示其大小，也可遥控进行调节。
对音量、高音、低音采用数字化控制，对系统过压、过流、中点电位偏离保护，对系统温度过高进行智能散热。
本系统前级采用电子管放大后级采用晶体管放大，以满足人们的听音要求。
【关键词】高保真;智能;功放一、系统介绍1.创作动机随着现代科技发展越来越快，城市正在现代化的进程中，随处都能感知到声音，当人们在疲劳、烦躁时，总是想通过优美的音效环境来缓解压力。
传统的功放在音量调节时存在滑动噪声，音效差，没有很好的保护系统需要有线传输信号。
因此一个智能化、实用性的放大系统是必不可少的。
2.创作目的为了减小音量调节噪声，实现无线调节音量、高音、低音。
使开关系统能够方便智能控制，根据人们的要求营造一个很好的音效环境，能够在各种环境都能使用，并能对系统本身有很好的智能保护措施，使系统持久耐用减少用户的维修费用。
3.设计创新点通过无线控制功放的模拟量的调节，显示模拟量调节的大小，系统智能保护系统，使系统智能化，方便，持久耐用，并营造好的音效环境。
二、工作原理用户通过（手机、电脑）等蓝牙连接系统蓝牙设备，通过遥控开关系统、调节音量、高低音，并通过显示电路对其大小显示，通过相关电路对系统关键点的电压进行监测送回单片机，同时通过软件对其大小进行判断是否超过安全值，如果超过相关保护电路动作，通过温度传感器对系统的温度进行监测并送回单片机，同过软件对其大小进行判断是否超过安全值，如果超过散热装置动作。
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毕业设计(论文)说明书随着国家经济蒸蒸日上，现代科技不断发展，这些使人们在物质享受之余，也有了更多的精神享受的需要。
其中之一：音乐，便是一种古老的享受形式。
而高保真音响就是欣赏音乐的物质基础。
本论文将以性价比为导向，兼顾基本的高保真的技术指标，讨论了适合初级发烧友的高保真功放。
论文由浅至深，结合图示给出了高保真音响的相关知识，以及整个功放的工作过程的细节。
同时还介绍了各个主要芯片自身的特点及如何去设计这个系统来满足一定的技术指标。
论文尽可能通俗地来介绍高保真音响，让大家能从中学到基本的高保真音响的知识的同时，还能学会如何制作高保真音频放大器。
在技术层面上，系统主要是采用集成芯片来完成的，因此对于一个初级发烧友来说相对简单，这个设计中用到了NE5532(曾经的“运放之皇”)做前置放大芯片，典型的增益为20dB；用NSC公司的LM1036做音调芯片，通过改变直流控制电压来实现音调控制。
后级功率放大部分用的也是NSC公司的一款经典芯片――LM1875芯片，用4片LM1875驳接成了左右声道的BTL电路,以取得更大的功率以及更好的音效。
在论文的后面部分，着重的讲述了制作和调试中遇到的软件、硬件上的问题以及如何解决，并给出了高保真音频放大器性能指标的国家标准测量方法。
这些可以成为大家制作过程中的一些的提示以及测试的依据。
关键词：高保真；集成芯片；BTL；音调控制With the development of our country’s economy and the modern technology. People no –longer just enjoy the happy brought from material, they also learned to enjoy the spiritual things. For instance: Music, an old fashion of the enjoyments. And Hi-Fi(high fidelity) audio system is the very suitable intermedia for enjoying music.So this dissertation focused on the Hi-Fi amplifiers for those primary audiophiles on this field. It tried to let people cost less and at the same moment , get enough enjoyment from Hi-Fi amplifiers and satisfy those basic standards of Hi-Fi system. This dissertation presented the ideas from easy to hard, and described the relative knowledge of the Hi-Fi audio system with those graphics and diagrams. It also wrote about the details of the whole working process of this design gradually. This dissertation also introduced those characteristics of those chips used in my design, and how to realize those system’s targets given .The dissertation tried to introduce Hi-Fi audio system commonly,and let you learn some basic knowledge of this Hi-Fi system, at the same time , eventually learn how to accomplish a Hi-Fi audio amplifier.Refer to the technology, IC was used to finish this graduate design, because it's relatively easier for primary audiophiles to design a audio amplifier. The pre-amp is NE5532, which was ever called as "The KING of amplifiers" ,and its typical gain is 20dB;LM1036 produced by NSC(National Semiconductor Company) was used here for tone adjustment IC. And LM1036’s tone control can be controlled by changing the DC control voltage. The second amplifier IC is LM1875, also made by NSC. It is very classical . Four LM1875 chips were used to make a BTL(Balanced Transformer Less) circuit of each channel to achieve more power and to make the whole system’s timbre to be better.The last paragraph of this dissertation, I mainly introduce some software and hardware problems I met during making the board and debugging, and how I solved those problems. Also I presented you the national standard test methods for audio amplifier characteristics. Hope these can be your hints and help during your executing for audio amplifier.Key words: Hi-Fi; Integrated Circuit; BTL; Tone control目录引言 (1)1 高保真音响系统 (1)1.1 高保真音响系统定义 (1)1.2 高保真音响系统组成 (2)2 高保真功率放大器 (3)2.1 功率放大器种类 (3)2.2 高保真功率放大器主要技术指标 (4)3 功放电源 (8)3.1 功放电源概述 (8)3.2 功放电源组成 (8)3.3 整流滤波电路 (10)3.4 稳压电路 (13)4 方案论证及阐述 (14)4.1 设计要求 (14)4.2 方案论证 (14)4.2.1后级放大器方案选定 (14)4.2.2前置放大器方案选定 (14)4.2.3音调芯片方案选定 (15)4.2.4电源方案选定 (15)4.3 具体方案阐述 (15)4.3.1前级放大器方案阐述 (15)4.3.2后级放大器方案阐述 (19)4.3.3功放电源方案阐述 (22)5 高保真功放制板 (23)5.1 制板注意事项 (23)5.2 制板经验总结 (24)5.2.1制板步骤 (24)5.2.2Protel99se的使用经验总结 (25)5.2.3制板遇到的问题 (26)6 功放调试 (26)6.1 调试步骤 (27)6.2 模块调试 (27)6.2.1电源调试 (27)6.2.2音调模块调试 (27)6.2.3前置放大模块调试 (28)6.2.4后级功放模块调试 (28)6.3 整体调试 (28)7 高保真功放性能指标测试 (29)7.1 性能指标测试的必要性 (29)7.2 主要性能指标测试 (29)7.3 测试所用仪器 (32)7.4 测试结论 (32)8 总结 (33)8.1 完成程度 (33)8.2 技术优点 (33)8.3 技术缺陷 (33)8.4 毕设感受 (33)谢辞 (34)参考文献 (35)附录 (36)附录1电路原理图 (36)附录2 PCB 图 (39)引言音乐是一种迷人的艺术，对于一些十几年前的旋律与歌词我仍然熟稔于心，难以忘怀，怀念音乐给我的感觉。
音乐这种传递人类感情的艺术形式，它是需要一种载体来表达，而最好表达的便是高保真音响，如实地还原音乐，表达音乐。
让人们从完全真实的音乐重放中汲取音乐的灵魂。
而今，科技发展，生活水平今非昔比，人们也欣赏水平也越高，大家越加追求音乐的还原性,所以音乐重放设备发展非常快。
也就是我们所谈及的高保真音响系统。
音乐重放设备的发展从1877年爱迪生发明留声机后，一直在不断地发展，重放设备由当年机械式录音/重播系统发展到现在的高科技数码系统，算到如今的话，进步可谓是翻天覆地。
不过其间的发展不是很均匀的，但是还是取得了一定的进展。
比如录放音以电动方式取代了机械方式，开始采用多极真空管等等。
音乐快速发展的时间是在1927年开始的，当时美国贝尔实验室公布了划时代的负反馈（负反馈，NFB）技术，声频放大器技术开始进入了一个新纪元。
现在的音响技术可以说是到达了一个相当成熟的阶段，就如唐朝的古诗，宋朝的词一般。
在技术如此成熟的环境下，从各种媒介能获得相当多的技术支持。
为了培养自己的动手能力，结合自己的兴趣和一直以来对音乐的爱好，参考过相关电路后，设计并制作一个集成芯片HI－FI音频功率放大器。
设计制作过程中考虑到满足给定的技术指标，同时也尽量提高性价比。
希望本论文能给发烧初级爱好者带来音响基本知识以及制作过程中的注意事项，要是能同时为普及音响事业的发展做一点点小推动就更好了。
1高保真音响系统1.1 高保真音响系统定义谈及高保真(High Fidelity，简称Hi—Fi)音响系统来，我想很多音乐爱好者，或者说很多一般的人，都在各种媒体中看到或者听到过这概念，不过大家不一定知道做何解释。
而且大部分音乐初级爱好者一定是非常好奇“高保真”这个概念的定义。
为了给大家解惑。
那么下面由专业术语来解释：美国IEEE(电子与电机工程师协会)出的《IEEE名词术语词典》一书对“Hi—Fi信号”的解释为Hi—Fi信号是指使用性能最好的先进器件，如话筒、功率放大器、音箱或耳机之类来对信号进行传送。