How to make a moody crystal light for under $10!

It is time to make good use of the Selenite crystal that has been sitting in my room for ages. I brought the crystal from a collection shop while ago on holiday in Devon for $2. You don't have to use the selenite crystal for this project, you can use any kind of crystal that is transparent or cloudy.

^{BTW, I am British, I have to use the American currency symbol because instructable dose not like the British currency symbol.}

Step 1: What You Will Need for the Project

Nothing really expensive, other than the RGB LED's and the crystal, they can be quite expensive in some place.

Double AA battery holder
Two AA batteries
A switch
A small piece of veroboard
Some wires
Transparent or cloudy crystal
A project box (I ran out of them, so I have to use a container)
RGB LED's (see next step)

Step 2: About the RGB LED's

The RGB LED's are not very easy to fine and you are unlikely to fine them in Radio Shack, Maplin, or in other little electronic stores. The best place to buy the RGB LED's is on the internet, the internet has everything. :-)

I brought 50 RGB LED's from this ebay store for $9, you can buy the LED's from a different seller.

In this project, I used three LED's, and I am going to use the rest for my other project. You can use much LED's as you want for your project,

The RGB LED's has a starting voltage at 3v, so you don't need to use resistors if you are going to power the LED's at 3v.

Also the RGB LED's tends to flicker or 'reset' when they are put in parallel together and being controlled by one resistor. It is a good idea to give every LED's their own resistor to prevent flickering. My LED's did not flicker bad, so I left them without resistor.

Step 3: Make a Hole in Top of the Container

I marked out where I am going to put the crystal and grabbed my dremel with a cutting head and started cutting out a hole on the container.

While I was cutting, some bits of plastic shattered and when flying everywhere, it is a good thing I was wearing goggles...

After I had done cutting and filed away the blur bits, I sprayed the container glossy black to give it a more stylish look.

Then, I made a mistake, I forgot to make a hole on the side of the container for the switch after I had sprayed the container black. So I make a hole for the switch and resprayed the whole container again because some paint came off.

Step 4: Build the Circuit

I soldered the RGB LEDs in parallel onto the veroboard. Soldered the switch between the positive output from the batteries and the positive side of the LED's. Then soldered the ground side of the LED's to the negative wire of the battery pack. It's simple.

You can do this without doing any soldering, just twist the wires together and hold the wires together with tape or glue.

Like all other LED's, RGB LED's have polarity and you can determine the polarity by the length of the leads.

If one lead is long, it is the positive side of the LED or the anode.
If the other lead is short, it is the negative side of the LED, or the cathode.

If you are going to power the RGB LED's higher than 3v, then you will need a resistor to protect the LED from too much power flowing through it.

Most RGB LED's consume 30mA at 3v, so here is a list of calculated specs on what resistor you should use at different voltages.

3v - (don't need to use a resistor)
4.5v - 56 ohm resistor (color code - green/blue/black)
6v - 100 ohm resistor (color code - brown/black/brown)
7.5 - 150 ohm resistor (color code - brown/green/brown)
9v - 220 ohm resistor (color code - red/red/brown)
12v - 330 ohm resistor (color code - orange/orange/brown)

Also, you don't have to use an exact resistor from the specs, you can use a resistor that has similar ratings to the recommend ratings.

Step 5: Attach the LED's to the Crystal

I did in a rather simple and crude method. I wrapped paper around the crystal and taped it down, leaving some space on the bottom of the crystal to put the LED's in.

Then I taped the LED's on the bottom of the crystal.

Step 6: Put Everything in the Container

Then put everything in the container (or the project box). I glued the battery pack and the switch in place, but I left the crystal lose, it should not cause too much problem.

Step 7: Enjoy...

When you first switch it on, it will glow in this first sequence, red, green and blue... That is why the color changing LED's are called RGB.

Then after the first sequence, because all the LED's have slightly different timing on when to change color, it will produce a much wider range of unique colors. I had the crystal glowing white once, but that happens very rarely.