篮球比赛计时器教程.docx

课程设计说明书课程设计名称：电子技术课程设计题目：篮球比赛计时器学院：电气与电子信息学院学生姓名：专业：电气工程及其自动化学号：指导教师：日期：2016年 7 月2 日课程设计题目摘要：本设计是脉冲数字电路的简单应用，设计了篮球竞赛24秒和12分钟倒计时器。此计时器功能齐全，可以直接清零、启动、暂停和连续以及具有报警功能，同时应用了七段数码管来显示时间。此计时器有了启动、暂停和连续功能，可以方便地实现断点计时功能，当计时器递减到零时，会发出报警信号。本设计完成的中途计时功能，实现了在许多的特定场合进行时间追踪的功能，在社会生活中也具有广泛的应用价值。本电路主要有五个模块构成：秒脉冲发生器、计数器、译码显示电路、控制电路和报警电路。控制电路直接控制计数器启动计数、暂停/连续计数、译码显示电路的显示等功能。当控制电路的置数开关闭合时，在数码管上显示数字24，每当一个秒脉信号输入到计数器时，数码管上的数字就会自动减1，当计时器递减到零时，报警电路发出光电报警与蜂鸣信号。　　关键词：计数器 24秒倒计时译码显示电路控制电路报警电路Abstract：This design is the simple application of the pulse digital circuit, design of the basketball competition 12 minutes and 24 seconds and the timer. The timer function is all ready, can be directly reset, start, pause, continuous and has alarm function, and application of the seven segment digital tube to display the time. The timer start, pause and continuous function, can easily achieve a breakpoint timing function, decreasing when the timer to zero, will send out alarm signal. This design completed the middle of the timing function, realized in many occasions for time tracking function, also has extensive application value in social life.This circuit is mainly composed of five modules: second pulse generator, counter, decoding display circuit, control circuit and alarm circuit. Control circuit control directly counter to start counting, pause/continuous counting, decoding display circuit, and other functions. When the control circuit of the load switch is closed, on the digital tube display digital 24, when a second pulse signal input to the counter, the Numbers on a digital tube will automatically minus 1, decreasing when the timer to zero, signals photoelectric alarm and buzzer alarm circuit.Keywords：Counter, and 24 seconds countdown, decoding display circuit, control circuit, alarm circuit目 录1前言11.1 设计背景11.2 设计目标11.3 实施计划11.4 必备条件12总体方案设计22.1 方案比较22.1.1方案一22.1.2方案二22.2 方案论证32.3 方案选择33单元模块设计33.1 各单元模块功能介绍及电路设计33.1.1 秒脉冲发生器和节次控制模块设计43.1.2 秒·分倒计数器模块设计63.1.3 译码器与显示器模块设计83.2 特殊器件的介绍93.2.1 74LS19