This Traffic Light Circuit can be used to control traffic on roads or in public places.In a Traffic light there are three different color bulb which are Green, Yellow/Amber and Red.
This project uses IC555 as Astable Multivibrator for rapid squire wave pulse generation. This clock pulse is feed to IC 4017 which is a Counter IC. In this counter IC, for every pulse fed to input pin-14, the High level output keeps shifting from D1 to D9 in cyclic order. See Circuit Diagram below.
Picture of our Traffic Light Project
At a time one output is higher (Positive) and other output pins of IC remains at low state.
The capacitor and resistor on pin 15 of IC4017 are used to reset the counter to zero (Red light ON) at initial power up.
IC = NE555 ( Timer IC) , IC CD4017 (Counter IC)
Diode = IN4007 or IN4148 6Pcs
POT = 470K
Resistance = 22K, 100K, 220 Ohms X 3Pcs
Capacitor = 0.1 Mfd, 1 Mfd, 10 Mfd.
LED= Red, Green and Yellow
9 Volt Battery with Snap
Switch, Wire, Clamp, PCB