Do you have some spare LED's lying around? Do you have some spare time and are you looking for something to do? Why not make an LED TREE. Its fun as long as you follow the steps and use a clean Soldering iron. The result is an amazing piece of art that you can look at for hours.
Step 1: Materials
1) Soldering Equipment
2) I think it was 13 LED's (you choose how many you want. they should also be brand new so that they have long leads)
3) if you use 13 LED's you also need a 3.9 ohm resistor
4) AA battery case
5) thick wire (strong enough to hold up your bunch of LED's. Must be a conductor)
6) If you want Hot Glue to hold the wires in place
7) Blu tack to assist with soldering
Step 2: Fidgety Job of Soldering LED's Together
Since you want the all LED's in parallel you have to solder all the cathodes and anodes together. first solder a cross of four LED's together then add two on each side to. the rest of the LED's have to be soldered on at an angle. Since new LED's have different length cathode and anode the LED's can easily be attached at an angle. During this process use a 9V battery (with a resistor of course) after every LED added to test wether you got the polarity right. otherwise if you finish and it doesn't work it will be alot harder to fix the mistake. Also keep checking your soldering for bridges. I advise you to clean your soldering iron thoroughly before you start or this process will cause you alot of pain. It took me alot longer to get it done than i thought. At least this will improve your soldering.
Step 3: Soldering LED Bunch to Battery Case
Solder the 3.9 ohm resistor to one of the battery case tabs. solder two thick wires to that resistor and the other tab. Cut both wires at the same distance from the battery case and solder the LED bunch to those two wires ( so that the whole LED bunch is forward biased). then insert some batteries into the battery pack and stare at your wonder!
Step 4: Further Development
You could make the LED bunch somewhat bigger. There is one problem though, its hard enough to solder 13 LED's together. You might be asking yourself why this idiot didn't put in a switch, well...... I couldn't be bothered. but of course you can if you want. You might also be wondering why i didnt use a 9V battery well....... the 9V battery couldn't keep the LED TREE standing up, and of course i dont like 9V batteries because they cost more.
As you might have notice the other photos are my SOLAR NIGHT LIGHTS. They are made by buying a cheap solar garden light and taking it apart so I can put the circuit in a better case. The other star light is the solar night light where i stuck the whole solar garden light on the window. The reason why I'm telling you this is because you can make a solar night light with an LED tree.
I hope you enjoyed this project!