How to Connect an LED to a Battery
In this tutorial, you will learn some basics about electronics, enough to get you started, and an exercise to connect your very own LED to a battery.
Materials:
- Battery (9V)
- Wire
- Wire with battery snap
- LED
- Resistor (220 ohms)
- Breadboard
Background:
A circuit is a path where electrical current flows through which requires a source of energy (battery) and needs to constantly stay connected. Think of a tube of water, if the tube is broken, the water will leak and not be sent to where it needs to go; electric energy works in a similar way.
The higher the voltage, the faster the current will flow, but if you have resistance (resistors) you can slow down and control the energy current more.
LED stands for Light Emitting Diode used in most electronic devices and emit light when current flows through it. The LED has 2 legs
- The longer leg is positive
- The shorter leg is negative
- The negative side has a flat side on the bulb
An LED always needs a resistor with it to slow down the electric current so it doesn’t ruin the LED. This is also true with many other electrical components such as sensors, controllers, or even using multiple LEDs.
Breadboards are used to test electronics out before soldering the components which renders them permanent. The columns on either side are known as power rails that allow current to flow vertically. The numbered rows in the center columns allow current to flow horizontally.
This gives a general background to quickly get a basic understanding to get started with electronics and the parts necessary to achieve this exercise. If you want to learn in more detail how current flow works, the individual parts or example projects, please refer to the references for this exercise linked at the bottom of this page.
Process:
Note: Keep all electrical components disconnected from the battery until you are ready to test the circuit and everything is connected together.
- Connect the LED across 2 numbered rows.
- Connect the negative side (short leg) to the negative power rail using a wire.
- Connect the resistor in line with the positive side of the LED.
- Connect the other end of the resistor to the positive power rail using a wire.
- Now that everything is connected together, connect the positive end of the battery the power rail with the positive side of the LED and current flow. Connect the negative end to the adjacent power rail with the negative side of the LED and current flow.
- The LED should automatically turn on once connected to the battery.
Troubleshooting:
Sometimes you run into problems or errors. Don’t get frustrated, it happens to all of us!
Let’s go through what could potentially be the problem:
Mixing up positive and negative.
This is the common cause of issues when first starting out. Make sure positive connects to positive and negative connects to negative. So in this case, the long leg of the LED connects to the positive (red wire in example) power rail; it is ok to have a wire or resistor in between.
Make sure everything is connected with each other.
Pretend your finger is the current and run it along the circuit starting at the positive end of the battery and end it at the negative end of the battery. Refer to the image to make sure they look similar.
Sometimes components are just bad.
Your wiring looks perfect! So why isn’t the LED glowing? Well there are times when the LED, the resistor, or even the battery has gone bad. It’s always best to have backups available just in case this happens.
There are ways to thoroughly check each component, which will be available in a separate tutorial, but check the reference page in the meantime.
Ideation:
Ok, you got an LED to turn on and off. Woohoo! You did it… now what?
Well you’re a cosplayer who came here to learn new skills for cosplay right? You probably want to hurry up and make glowing fantastical wings or add effects to a sword or make armor look menacing; all while not breaking bank.
Patience, everyone starts somewhere, so let’s come up with a couple ideas of what you could do with turning an LED on and off.
Well you can power up crystals! So instead of buying LED crystal necklaces, you can now make your own!
For you gamers, you can elevate your Fallout pip-boy by backlighting the screen to make it even more cool!
You can get spooky by making the eyes of your mask glow:
Or you get to play with fire for all the characters that control or manipulate fire:
Here’s how I used this concept of electronics within my own cosplay props.
That’s just the beginning! The purpose here was to introduce the concept and get you to think outside of the box to not only bring your favorite characters to life, but also elevate your craft so you can look even more super too! Now you have a new tool, go make your cool costume even cooler!
