Traffic-Light is a common project given to engineering students. In this purpose, I include this project in my list. After getting the schematic (I forgot where I get this), I started to make one. I modified the circuit because it doesn’t work correctly. The diode in the pin10 of 4017 counter must be connected to the red LED. Here is the circuit(unmodified).
Components List:
- resistors: 470 ×3, 22k, 100k
- capacitors: 0.1µF, 1µF 16V radial, 10µF 16V radial
- diodes: 1N4148 ×6
- LEDs: red, amber (or yellow), green
- 1M preset, horizontal
- 555 timer IC, such as NE555
- 4017 counter IC
- on/off switch
- battery clip for 9V PP3
It uses a 555 timer IC and a 4017 counter IC. In addition, by adjusting the 1M preset, the sequence can be varied from 7 seconds to 2.5 minutes.
I formed it in a breadboard to show you how it works.
Here is a video:
Reminder:
Please understand that this is just a simple traffic light circuit. You can design a different kind of traffic light like traffic light for both intersection, traffic light for railway, etc. This is just a ‘small-time project’.
You can also check an improved version(two way traffic light) of this circuit on this blog.
http://circuitdesolator.blogspot.com/2011/01/traffic-light-circuit-based-on-4017.html
Rowatronix 