摘 要：隨著各種交通工具的發(fā)展和交通指揮的需要，第一盞名副其實的三色燈(紅、黃、綠三種標志)于1918年誕生。它是三色圓形四面投影器，被安裝在紐約市五號街的一座高塔上，由于它的誕生，使城市交通大為改善。
當前，大量的信號燈電路正向著數(shù)字化、小功率、多樣化、方便人、車、路三者關(guān)系的協(xié)調(diào)， 多值化方向發(fā)展隨著社會經(jīng)濟的發(fā)展，城市交通問題越來越引起人們的關(guān)注.隨著社會的發(fā)展,城市規(guī)模的不斷擴大,城市交通成為制約城市發(fā)展的一大因素,因此,有許多設(shè)計工作者為改善城市交通環(huán)境設(shè)計了許多方案,而大多數(shù)都為交通指揮燈,本電路也正是基于前人設(shè)計的基礎(chǔ)上進行改進的.全部有數(shù)字電路組成,比較以前的方案更為精確。
關(guān)鍵詞：控制器 計數(shù)器 信號燈 譯碼電路

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

目錄
1、引 言................................................................................................................................1
2、交通信號燈基本原理及設(shè)計方法 ...................................................................................2
3、主控制器............................................................................................................................4
3.1 74LS90引腳排列圖與邏輯圖....................................................................................4
3.2 74LS90的功能表及引腳功能....................................................................................5
4、計數(shù)器................................................................................................................................6
4.1計數(shù)器的作用..............................................................................................................6
4.2計數(shù)器的工作情況......................................................................................................6
4.3控制信號燈的譯碼電路的真值表..............................................................................7
4.4置數(shù)電路......................................................................................................................8
4.5狀態(tài)譯碼電路..............................................................................................................10
5、譯碼顯示電路....................................................................................................................11
5.1共陽極LED七段數(shù)碼管............................................................................................11
5.2 74LS247譯碼器..........................................................................................................12
6、555振蕩器構(gòu)成的秒脈沖電路.........................................................................................14
6.1 555定時器的引腳.......................................................................................................14
6.2 555定時器構(gòu)成的多諧振蕩器...................................................................................16
6.3 555定時器工作原理...................................................................................................17
7、交通燈信號燈控制總體框圖............................................................................................19
8.組裝和調(diào)試過程...................................................................................................................19
總 結(jié)......................................................................................................................................21
參 考 文 獻............................................................................................................................22