毕业论文 交通灯控制系统的简易设计.doc

摘 要：随着各种交通工具的发展和交通指挥的需要，第一盏名副其实的三色灯(红、黄、绿三种标志)于1918年诞生。它是三色圆形四面投影器，被安装在纽约市五号街的一座高塔上，由于它的诞生，使城市交通大为改善。
当前，大量的信号灯电路正向着数字化、小功率、多样化、方便人、车、路三者关系的协调， 多值化方向发展随着社会经济的发展，城市交通问题越来越引起人们的关注.随着社会的发展,城市规模的不断扩大,城市交通成为制约城市发展的一大因素,因此,有许多设计工作者为改善城市交通环境设计了许多方案,而大多数都为交通指挥灯,本电路也正是基于前人设计的基础上进行改进的.全部有数字电路组成,比较以前的方案更为精确。
关键词：控制器 计数器 信号灯 译码电路

Traffic signal control system design
Abstract: With the development of various modes of transport and traffic control needs, the first truly three-color lights lights (red, yellow, green, three kinds of signs) was born in 1918. It is the tri-color circular four projectors were installed in New York City on the 5th Street, a tower, due to its birth, so that urban transport greatly improved.
At present, a large number of signal circuits is toward digital, low-power, diversification, convenience of people, vehicles, roads relations between the co-ordination with the development of multi-value in the direction of social and economic development, urban transport problems are increasingly a cause for concern . With the development of society, the continuous expansion of city size, urban transport as a constraint to urban development, a major factor, therefore, there are many design practitioners to improve the urban traffic environment design a number of programs, and most of them for the traffic lights, It is precisely because our predecessors in this circuit is also designed on the basis of improvement. all of a digital circuit to compare the previous program more precise.

Key words: controller counter signal decoding circuit

目录
1、引 言................................................................................................................................1
2、交通信号灯基本原理及设计方法 ...................................................................................2
3、主控制器............................................................................................................................4
3.1 74LS90引脚排列图与逻辑图....................................................................................4
3.2 74LS90的功能表及引脚功能....................................................................................5
4、计数器................................................................................................................................6
4.1计数器的作用..............................................................................................................6
4.2计数器的工作情况......................................................................................................6
4.3控制信号灯的译码电路的真值表..............................................................................7
4.4置数电路......................................................................................................................8
4.5状态译码电路..............................................................................................................10
5、译码显示电路....................................................................................................................11
5.1共阳极LED七段数码管............................................................................................11
5.2 74LS247译码器..........................................................................................................12
6、555振荡器构成的秒脉冲电路.........................................................................................14
6.1 555定时器的引脚.......................................................................................................14
6.2 555定时器构成的多谐振荡器...................................................................................16
6.3 555定时器工作原理...................................................................................................17
7、交通灯信号灯控制总体框图............................................................................................19
8.组装和调试过程...................................................................................................................19
总 结......................................................................................................................................21
参 考 文 献............................................................................................................................22