This is a super simple project that is a good intruction into circuits, soldering, and LEDS.
Step 1: Materials
You will need:
1. A piece of cardboard (any size will do)
2. Copper foil tape (usually for soldering stained glass)
3. Soldering iron
6. Battery pack
Step 2: Placing the Copper Tape
Rip two pieces of copper tape in equal lengths, enough to fit across the length of your cardboard.
Pull the backing off the tape and stick it down. Tuck the edges behind the cardboard.
Label one tape positive and the other negative. This will help when soldering the LEDs and completing your circuit.
Step 3: Adding Solder
Add dots of solder along your copper tape.
Touch the soldering iron against the copper tape to heat it. Then, gently push the solder against the iron. This should melt the solder into neat piles along the copper tape.
Create two dots for every LED you want to place along the circuit, plus two more for the power source.
Adding these solder dots to the copper tape will make it super easy to attach the LEDs and battery pack. You shouldn't need to use more solder after this step.
Step 4: Soldering Battery Pack
In order to solder the battery pack, it is important to line up the positive and negative ends to the proper places.
Red = Positive
Black = Negative
Take your negative wire and hold the exposed wires against the solder dot. Heat this dot with your soldering iron until it covers the wire.
Repeat this step with your positive wire.
Step 5: Soldering the LEDs
Each LED has a positive and a negative lead. I've labeled them in the picture above. The longer lead is positive and the shorter lead is negative. It is really important to line up the positive and negative leads correctly along your circuit!
For this project, I bend the ends of the LED a tiny bit so they are easier to solder.
After lining up the positive and negative ends, it's time to solder the LED. Like the battery pack, you just have to hold the LED against the solder dot, heat up the dot, and wait until it is covered in solder.
Repeat this on the other side and your LED should light up!
Step 6: Finished!
Now you're done!
You can add as many LEDs as your battery will power to the circuit, and they will all light up!
This project is a good introduction into the bascis of circuits, LEDs, and soldering. It can be applied to many different projects, basically anything that needs an LED light track, without costing much or taking much effort.