Design of simple digital circuit traffic light

1. Curriculum design requirements

1.1 subject

Traffic light controller based on digital circuit

1.2 Design task

1. At the crossroads , from A（ East west direction ）、B（ North South ） Two intersecting roads make up ;
2.A The street is green , meanwhile B The street red light is on , keep 10 second ;
3.10 Seconds later A The street lights go out , The yellow light is on , keep 3 second ;
4.3 Seconds later A Street yellow light and B The street red lights go out at the same time , then A The street red light is on ,B The street is green , And keep 10 second ;
5.10 Seconds later B The street lights go out , The yellow light is on , keep 3 second ;
6.3 Seconds later A Street red lights and B The street yellow lights went out at the same time , then A Street green lights and B The street red light is on , Follow the above process to cycle .

2. Part content

2.1 Design thinking

2.2 Second pulse generation

Adopt multivibrator circuit , The choice is 555 Timer generation .

2.3 Counting module

The delay counting module of the traffic light is 74LS191 Synchronous hex add counter .

2.4 State switching

State switching adopts synchronous decimal addition counter 74LS160.

2.5 Traffic lights show

The NAND gate logic circuit is used to judge the state , Control the display of traffic lights ;
And gate is specifically used 74LS08 Chip and non gate 74LS04 chip , Transfer the state to the controller 74LS160 The output signal is displayed by the traffic lights after calculation .

3.Multisim Simulation effect

explain ：
1. This is my homework for the digital and electronic course in my freshman year , It's time to clean up the computer data , Just sort it out ;
2. Now it seems that there are many shortcomings , For example, the display nixie tube only uses 1 position , Display in hexadecimal , It is better to use the countdown to show... Etc ;
3. Due to the limited level at that time , There will inevitably be many mistakes and shortcomings , So this design is only for reference ;

Course papers and Multisim The simulation circuit can be in CSDN Upload and download ;
CSDN Download link ：https://download.csdn.net/download/xiaopikadi/10886099

Those without integral can also pay attention to my WeiXin official account ： A Wei plays Electronics , Reply on the background message page traffic lights Get all the information ;