# LED Roulette Circuit Using 555 Timer | DIY | Step by Step

276

2

Posted

## Introduction: LED Roulette Circuit Using 555 Timer | DIY | Step by Step

Hi Today Instructable is very simple and easy to build DIY LED Rouletter Circuit
A Complete Step By Step Video Tutorial is also given in the video below.

Here, we are going to show you how to make an LED Roulette Circuit using 555 timer IC, before starting the tutorial let you know about what the roulette is, it’s a casino game named after the French word which means little wheel. As same, here we are making a wheel (or circle) shaped led blinker, using 555 timer IC placed in Astable mode, and IC 4017 which is decade counter IC and small needful components.

## Step 1: Hardware Components

• 555 Timer IC
• Resistors - 220 Ohm, 1k and 10k
• Capacitor - 10µF
• LEDs – 8
• Battery - 9v

## Step 2: Circuit Diagram

The 4017 IC is a truly useful IC in project works, timer based games and in various DOCTRONICS construction kit like Light Chaser and Matrix Die. It’s having lots of useful application if we think, you can check all our 4017 IC related projects here. If we talk about the technical part, it’s a CMOS decade counter decoder circuit. This IC is used to generate output in a sequence manner like it start from zero and goes up to 10. It shifts it output from one pin to another by applying clock pulse at PIN 14. First clock pulse makes first output PIN (PIN 3) HIGH, second clock pulse makes first PIN LOW and second PIN (PIN 2) HIGH, third clock pulse makes third PIN HIGH, and so on. So it creates sequential ON and OFF of all the 10 OUTPUT PINs which is needed in our LED Roulette circuit. Here this clock pulse is generated by 555 Timer IC in astable mode.

## Step 3: Working

Now we will connect the LEDs in a roulette design (circle shape), as we used 8 LEDs which are connected by the output pins of the 4017 IC according to the sequence of output, start from zero and goes up to 10 but we are using only 8 output pins as the number of LEDs are 8 and its gets the clock pulse or pulse input from the 555 timer IC in Astable mode. As the LEDs start blinking we can adjust the speed of the blinking LEDs by setting the value of resistance through a potentiometer connected in the circuit because changing the value of resistance will change the oscillation frequency of the 555 timer IC, hence the rate of clock pulse. You can calculate the exact value of resistance and capacitance in the circuit for desired output clock pulse, with this 555 Astable Calculator.

## Recommendations

• ### Large Motors Class

7,829 Enrolled

• ### Spotless Contest

We have a be nice policy.