课程设计 数字电子钟.doc

华 南 农 业 大 学
电子线路综合设计
数字电子钟设计
2010年6月
摘 要
在生活中的各种场合经常要用到电子钟,现代电子技术的飞跃发展,各类智能化产品相应而出,数字电路具有电路简单、可靠性高、成本低等优点,本设计就以数字电路为核心设计智能电子钟。
数字钟是采用数字电路实现对时,分,秒数字显示的计时装置,广泛用于个人家庭,车站, 码头办公室等公共场所,成为人们日常生活中不可少的必需品,由于数字集成电路的发展和石英晶体振荡器的广泛应用,使得数字钟的精度,运运超过老式钟表, 钟表的数字化给人们生产生活带来了极大的方便,而且大大地扩展了钟表原先的报时功能。因此,研究数字钟及扩大其应用,有着非常现实的意义。本设计电路由计时电路、动态显示电路、控制电路、显示电路等部分组成,在数码管上显示24小时计时的时刻,具有清零、保持、校时、报时的功能,并在此基础上增加了星期显示的功能。
数字钟计时的标准信号应该是频率相当稳定的1HZ秒脉冲,所以要设置标准时间源。数字钟计时周期是24小时,因此必须设置24小时计数器,应由模为60的秒计数器和分计数器及模为24的时计数器组成,秒、分、时由七段数码管显示。为使数字钟走时与标准时间一致,校时电路是必不可少的。设计中采用开关控制校时直接用秒脉冲先后对“时”,“分”计数器进行校时操作。能进行整点报时,在从59分50秒开始,每隔2秒钟发出一次“嘟”的信号,连续五次,此信号结束即达到正点。
关键字 振荡器 分频器 译码器 计数器 校时电路 报时电路
目 录
1 前言·····································································4
2 设计任务·································································4
2.1 课程性质及目的·························································4
2.2 设计要求及指标·························································5
3 数字电子钟的组成和基本工作原理···········································5
3.1 振荡器·································································6
3.2 分频器·································································7
3.3 计数器·································································7
3.4 译码显示电路···························································7
3.5 校时电路·······························································7
3.6 报时电路·······························································7
4 设计步骤与方法···························································7
4.1 振荡电路·······························································7
4.2 分频器电路·····························································8
4.3 计时器电路·····························································9
4.4 译码显示电路···························································10
4.5 校时电路······························································12
4.6 整点报时电路··························································13
5 组装和焊电路板··························································14
6 调试····································································14
6.1 调试原则及顺序·························································14
6.2 调试过程中出现的问题和解决方法········································15
7 结论··································································· 15
8 收获和体会······························································16
致谢······································································17
参考文献··································································18
英文摘要··································································19
附录······································································20
1 前言
中国是世界上最早发明计时仪器的国家。有史料记载,汉武帝太初年间(纪元前104-101年)由落下闳创造了我国最早的表示天体运行的仪器——浑天仪。东汉时期张衡创造了水运浑天仪,为世界上最早的以水位动力的观测天象的机械计时器,是世界机械天文钟的先驱。
由此可见,我们的古人在很早以前就已经在计时方面取得了一系列的成就,随着人类科技的一步一步发展,我们使用的计时工具日益先进。
20世纪末,电子技术获得了飞速的发展,在其推动下,现代电子产品几乎渗透了社会的各个领域,有力地推动了社会生产力的发展和社会信息化程度的提高,同时也使现代电子产品性能进一步提高,产品更新换代的节奏也越来越快,数字中已成为人们日常生活中的必需品,广泛用于个人家庭以及车站、码头、剧场、办公室等公共场所,给人们的生活、学习、工作、娱乐带来了极大的方便。由于数字集成电子技术的发展和采用了先进的石英技术,使数字钟具有走时准确、性能稳定、集成电路有体积小、功耗小、功能多、携带方便等优点,因此在许多电子产品设备中被广泛应用。
电子钟是人们日程生活中常用的计时工具,而数字式电子钟又有体积小、重量轻、走时准确、结构简单、耗电量少等优点而在生活中被广泛应用,因此本次设计就用数字集成电路和一些简单的逻辑们电路来设计一个数字式电子钟,使其完成的现实功能。
本次设计以数字电子为主,分别对1S时钟信号、秒计时显示、小时计时显