Instructables

Building a Simple 9V LED Stoplight

Picture of Building a Simple 9V LED Stoplight

These instructions will show you how to build your own LED stoplight powered by a 9 volt battery.

This LED Stoplight is a fairly simple, cheap project that can teach you about some simple, but very useful electronic components including the 4017 Decade Counter, the 555 Timer IC, and diodes. You will also be able to obtain some good practice in circuit design and be on your way to becoming a better engineer. I will start out by taking you through an introduction to some of the more complex devices used in this project, for those of you who don't have a ton of practice in the electrical engineering field. Then I will take you through the assembly process.

Estimated Time: 1 - 4 hours (depending on your skill level)
Estimated Cost: $5 - $15

Materials:
- 9V Battery
- Battery Snap
- 4017 Decade Counter
- 555 Timer IC
- 1 or 2 breadboards
- Jumper wires
- 3 LEDs (1 Green, 1 Yellow, 1 Red)
- 10 (1N4148) Diodes
- 7 Resistors
       - 2 10 kΩ
       - 3 680 Ω
       - 2 1 kΩ
- 2 Capacitors
       - 1 100 uF (u = micro)
       -
1 10 nF

 
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Step 1: Where to find the components?

Picture of Where to find the components?

Most of these materials can be picked up at your local Radioshack or electronics component store. If you have the time for shipping and handling you can purchase these materials online for around 10 - 30 cents a piece, but if your anxious to get started you'll have to hope that you can find them at a local store. Unfortunately, some Radioshack stores may not carry the IC components, such as the 4017 Decade Counter and the 555 Timer, but they should carry the rest of the materials needed (although not at the most reasonable of prices.)