南京理工大学电子电工综合实验

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1、电子电工综合实验（Ⅱ）实验报告—多功能数字计时器设计姓名:学号：学院(系):电子工程与光电技术学院专业:通信工程指导：电子技术中心实验日期：2012年9月16目录1．电路目的··························································32．设计内容简介及要求···········································33．实验原理··························································33.1整体设计原理················

2、······························33.2秒信号发生器·············································43.3计数器·····················································53.4清零电路·························16···························63.5校分电路····················································73.6报时电路················

3、············································74．遇到的问题及解决方法········································84.1调试过程······························································84.2问题与解决···················································94.3感想与体会···················································95．附

4、录································································105.116参考文献······················································105.2电路总图······················································115.3元件清单······················································115.4芯片引脚图·························

5、··························12一．实验目的1.巩固所学集成电路的工作原理和使用方法，学会在单元电路的基础上进行小型数字系统设计；2.培养大家的动手能力，独立完成实验电路的连接；3.增强分析问题与解决问题的能力，通过发现问题和解决问题对集成电路形成更全面的认识，提高调试电路的实验技能。二．设计内容简介与要求设计制作一个0分00秒～9分59秒的多功能计时器,要求如下：1）设计一个脉冲发生电路，为计时器提供秒脉冲（1HZ），为报时电路提供驱动蜂鸣器的高低脉冲信号（1KHZ、2KHZ）；2）设计计时电路：完成0分00秒～9分59秒的计时、译码、显示功能；3）

6、设计清零电路：具有开机自动清零功能，并且在任何时候，按动清零开关，可以对计时器进行手动清零。4）设计校分电路：在任何时候，拨动校分开关，可进行快速校分。（校分隔秒）165）设计报时电路：使数字计时器从9分53秒开始报时，每隔一秒发一声，共发三声低音，一声高音；即9分53秒、9分55秒、9分57秒发低音（频率1kHz），9分59秒发高音（频率2kHz）；6）系统级联。将以上电路进行级联完成计时器的所有功能。三．实验原理3.1整体设计原理数字计时器是一个对标准频率（1Hz）进行计数的计数电路。由于计数的起始时间与所需要的起点可能会不相同，所以需要在电路上加一个校分电路，以便将分时

7、刻跳到想要的时刻，这也是为了让蜂鸣器尽快的响起。为了使标准的1Hz时间信号准确并且稳定，实验中我们使用了石英晶体振荡器构成脉冲发生电路。为了使电路更加简单，实验中我们使用了一片CD4518的集成块对计时器的秒个位和分位进行计数，用74LS161构成模六（六进制）计数器实现对秒十位进行计数，当低位计数器计满10时向高位产生一个脉冲信号，触发高位计数器计数。由于所使用的计数器都有异步清零端，故可通过简单的电路就可以使电路具有开机清零功能和随时清零功能。用分频器对脉冲进行分频，2Hz用于较分，1KHz、2KH