文档介绍：该【数电课设之简易电子琴 】是由【hh思密达】上传分享，文档一共【20】页，该文档可以免费在线阅读，需要了解更多关于【数电课设之简易电子琴 】的内容，可以使用淘豆网的站内搜索功能，选择自己适合的文档，以下文字是截取该文章内的部分文字，如需要获得完整电子版，请下载此文档到您的设备，方便您编辑和打印。武汉理工高校《数字电子技术基础》课程设计说明20课程设计任务书学生姓名:辛威专业班级:电子1002班指导老师:韩屏工作单位:信息工程学院题目:简易电子琴设计(数字)初始条件:可选元件:集成运算放大器LM324、电阻、电位器、电容若干,=+12V,或自备元器件。可用仪器:示波器,万用表,直流稳压源,函数发生器要求完成的主要任务:(包括课程设计工作量及其技术要求,以及说明书撰写等详细要求)(1)设计任务依据已知条件,完成对简易电子琴电路的设计、装配与调试。(2)设计要求①设计一简易电子琴电路,按下不同琴键即变更RC值,能发出C调的八个基本音阶,采纳运算放大器构成振荡电路,用集胜利放电路输出。已知八个基本音阶在C调时所对应的频率如下表所列C调1234567if/Hz264297330352396440495528②选择电路方案,完成对确定方案电路的设计。计算电路元件参数并画出总体电路原理图,阐述基本原理。(选做:用PSPICE或EWB软件完成仿真。)③安装调试并按规定格式写出课程设计报告书。时间支配:,布置课程设计任务、选题;讲解课设详细实施支配与课程设计报格式的要求,课设答疑事项。、设计、制作与调试。。,进行课程设计验收和答辩。指导老师签名:年月日系主任(或责任老师)签名:年月日目 录1总体设计····················································································································································································································································································································································································································································42原理与器件选择·······························································································································································································································································································《数字电子技术基础》课程设计说明2······································································································································································································································································································································································································································83实物制作与输出波形···································································94调试与影响因素分析··································································145总结与体会·············································································15参考文献··················································································16附录1······················································································17附录2······················································································18武汉理工高校《数字电子技术基础》,大人小孩都爱玩,甚至一玩就是几个小时“简易电子琴”运用了一个集成电路振荡器,一些按键和一个音频输出连接到功率放大电路。现在的电子琴一般运用PCM或AWM采样音源。所谓采样就是录制乐器的声音,将其数字化后存入ROM里,然后按下键时CPU回放该音。甚至有一些高级编曲键盘可以运用外置采样(比如Tyros3的硬盘音色)。现代电子琴并非“仿照”乐器音色。它运用的就是真实乐器音色。当然,现在力度触感在电子琴里是必备的。而且现代电子琴还加上了老式电子琴的滤波器,振荡器,包络线限制来制造和编辑音色。甚至也带上了老式电子琴的FM合成机构。,完成对简易电子琴电路的设计、装配与调试。①设计一简易电子琴电路,按下不同琴键即变更RC值,能发出C调的八个基本音阶,采纳运算放大器构成振荡电路,用集胜利放电路输出。已知八个基本音阶在C调时所对应的频率如下表所列C调1234567if/Hz264297330352396440495528②选择电路方案,完成对确定方案电路的设计。计算电路元件参数并画出总体电路原理图,阐述基本原理。(选做:用PSPICE或EWB软件完成仿真。)武汉理工高校《数字电子技术基础》课程设计说明4③安装调试并按规定格式写出课程设计报告书。,它的振荡频率可以通过变更振荡电路中RC元件的数值进行变更。下面介绍一下555定时器以及其构成的多谐振荡器。555定时器成本低性能牢靠,只须要外接几个电阻、电容,就可以实现多谐振荡器、单稳态触发器及施密特触发器等脉冲产生与变换电路。它也常作为定时器广泛应用于仪器仪表、家用电器、电子测量及自动限制等方面。555定时器的功能主要由两个比较器确定。两个比较器的输出电压限制RS触发器和放电管的状态。在电源与地之间加上电压,当5脚悬空时,/3,/3。/3,则比较器C2的输出为0,可使RS触发器置1,使输出端OUT=1。/3,/3,则C1的输出为0,C2的输出为1,可将RS触发器置0,使输出为0电平。武汉理工高校《数字电子技术基础》课程设计说明5图1555定时器内部原理图图2555定时器引脚图它的各个引脚功能如下: 1脚:外接电源负端VSS或接地,一般状况下接地。 8脚:,~16V,的范围为3~18V。一般用5V。 3脚:输出端Vo 2脚:低触发端 6脚:TH高触发端 4脚:是干脆清零端。当此端接低电平,则时基电路不工作,此时不论TR、TH处于何电平,时基电路输出为“0”,该端不用时应接高电平。武汉理工高校《数字电子技术基础》课程设计说明6 5脚:VC为限制电压端。若此端外接电压,则可变更内部两个比较器的基准电压,当该端不用时,,以防引入干扰。7脚:放电端。该端与放电管集电极相连,用做定时器时电容的放电。图3555多谐振荡器电路图4555多谐振荡器工作波形多谐振荡器又称为无稳态触发器,它没有稳定的输出状态,只有两个暂稳态。在电路处于某一暂稳态后,经过一段时间可以自行触发翻转到另一暂稳态。两个暂稳态自行相互转换而输出一系列矩形波。多谐振荡器可用作方波发生器。接通电源后,假定是高电平,则T截止,电容C充电。—R1—R2— C—地,按指数规律上升,当上升到时(TH、端电平大于),输出翻转为低电平。是低电平,T导通,C放电,放电回路为C—R2—T—地,按指数规律下降,当下降到时(TH、端电平小于),输出翻转为高电平,放电管T截止,电容再次充电,如此周而复始,产生振荡,经分析可得: 输出高电平常间T=(R1+R2)Cln2 输出低电平常间T=R2Cln2振荡周期T=(R1+2R2)Cln2振荡频率f=1/T=1/[(R1+2R2)Cln2]依据这一原理,通过设定一些不同的RC数值并通过限制电路,依据确定的依次依次将不同的RC组件接入振荡电路,就可以使振荡电路依据设定的要求,有节奏的发出已设定的音频信号或音乐。其简易框图如下:武汉理工高校《数字电子技术基础》课程设计说明7555定时器按频率计算得出的阻值器按键输入扬声器engq 图5总原理框图 《数字电子技术基础》课程设计说明8 ,以生成音符。振荡器的反馈路径是从U1的输出3脚返回到输入感应插脚2和6。振荡器的频率由反馈电阻和插脚2和6所连接的10nF的电容器C4所确定。。这意味着音符的频率或音调将按相同的系数或总量上升,这和现代音乐理论音符之间的“十二平均律”是完全吻合的。通过电路图可以看到,扬声器连接在U1的输出插脚3和负极总线之间,另外还有一个150Ω的电阻器R9(起限流作用)和一个470μF的电解电容(隔直),这样的连接方式将使得集成电路的某些输出信号进入扬声器,其结果就是:只要振荡器工作,扬声器就可以按振荡器的频率来产生声音。 R1,R4:,R3,R5,R7:100 KR6:47KR8:51K R9:150ΩP1:100K电容C1,C2:2,2μFC3:47μFC4:10nFC5:470μFC6:1000μF二极管D1:1N4007三极管Q1,Q2:2N3904Q3:2N3906集成电路U1:NE555直流电源9V扬声器8Ω,《数字电子技术基础》,R2:11KR3,R4:10KR5:,R7:,R9::,R12:,R14::,R17::,R20::,R23::,R2,R3:10K电容C1:1nFC2:47nF开关若干3实物制作与输出波形图8简易电子琴实物图武汉理工高校《数字电子技术基础》课程设计说明10