I love the look of LEDs and reusing old stuff to make new stuff. My Light Up Smiley Face uses LEDs and recycles an old CD, an old power brick from a radio, and some other old "electronic stuff" I've salvaged. I made this with about $3 worth of LEDs. I soldered the LEDs but if you want to reuse them too, just join them using a sleeve to prevent shorting.
Step 1: What You Need
Here's what you need to make the Light Up Smiley Face:
20 Assorted LEDs (from Radio Shack, part 2761622)
IC (integrated circuit) board from the electronic stuff box at home
220 OHM 1/4 W 5% carbon film resistor (Radio Shack sells them if you can't salvage one: part 271-1313)
Power brick (recycled from a broken radio)
Solder, soldering iron with fine tip
An old CD
A piece of scrap wood
A soldering workstation with alligator clips is nice, if you have one. See my cool one in the picture.
Step 2: Draw a Design
Draw the design so you know where your positive and negative current is going and where all the parts fit.
Step 3: Check the Voltage of the Parts
Check the voltage of the LEDs, the resistor, and the recycled power brick so nothing burns up.
Step 4: Put the LEDs in the Board
Put the LEDs in the holes in the IC board. Make sure the polarity (+ and -) are lined up to solder a wire between all the + and - pins. Double check this. Have someone else double check this. If you mess up the polarity, you blow up your LEDs (bad).
Step 5: Cut the LEDs
Cut the LED pins shorter to solder them together to make a circuit. The long pin is the positive (+). The short pin is the negative (-). I used a fingernail clipper. Make sure the + and - are back in the correct places. (Did I say double check this?)
Step 6: Soldering the LEDS
If you haven't soldered much, practice soldering on wire before using your LEDs. A soldering gun with a very fine tip (like a pencil) works the best becuase this is extreme soldering in close quarters! Once you have practiced some and are confident, solder the LED pins together. This is the hardest part. If you get tired, take a break or find someone to do some lights for you. : )
Step 7: Solder the Resistors and Recycled Power Brick
Solder the resistor to the + side to regulate the voltage drop. I used 3 resistors to make the LEDs brighter.
Step 8: Prepare and Solder the Recycled Power Brick
A recycled power brick will have an end as shown in the picture. Cut that baby off and separate the + and - wires. Strip the plastic to expose the wirese. Solder the power brick's + and - ends to bring electrical power to the LEDs.
Step 9: Mount on the Recycled CD on an Old Chunk of Wood
Saw a groove in the wood to hold the CD.
Cut the CD and poke holes in it with a nail. Use fishing line to tie the face onto the CD. This picture shows a top view of the lit smiley face attached to the CD with fishing line.
Step 10: Back View
This picture shows a back view of the CD inserted into the wood. You can see the resistors and power brick connections.
If your CD doesn't stand up straight, you can glue gun it or tape it with electrical tape.
Step 11: Final Light Up Smiley Face and More Ideas...
Plug in an enjoy!
Some ideas I have to to improve and extend this project are:
Add a sliding switch on the wood and connect it to the unit so you don't have to plug and unplug the Light Up Smiley Face. (If you were looking closely, the switch was in my original design. I just need to find one to add.)
Drill small holes in the CD and put the IC board behind the CD for more light reflection. This would be really time consuming and would require a different design (to fit around the CD), but the light effect could be really neat.