Lego rocks! Its seriously cool and one of the many things that makes it cool is the huge range of Lego Star Wars minifigs that you can buy, either in stores or from auction sites like EBay. But what if you want your Star Wars minifigs to be a little bit special? Well, one way I tried recently was to give an Imperial Stormtrooper a fantastic pair of red glow-in-the-dark eyes. Just right for an evil meanie.

So, how did I do it? Well, it was all based on an idea that I found at this web site http://www.bigclive.com/joule.htm Its a device called a Joule Thief - no that's not someone who steal diamonds. A Joule Thief is like a torch without a case that will take either an AA or AAA battery in the holder and use whatever power is left in the battery to light a red LED. It can actually light any color of LED but Stormtroopers have got to have red eyes - right? The amazing thing about this circuit is that it will run right down to the bottom of the batteries charge if left running continuously, and will often provide a week of continuous low level light from a battery that would normally be considered dead.

So, first of all you'll need a LEGO Star Wars minifig to mod. I used an imperial stormtrooper since the helmet makes it easy to hide the electronics and the body is quite wide - just like me!

The other items you'll need are:

30 cm of 0.15 mm isolated copper wire.
A 1k ohm SMD resistor.
A general purpose swiching SMD transistor.
A red SMD LED.
A small ferrite bead, 6 mm outer diameter.
A minature push button.
A piece of thin copper foil for battery terminals (I butchered this piece from a PCB).
A piece of thick paper to mount behind the LED in the helmet.
and finaly a small piece of flexible dark red plastic film to go in front of the LED.

First you have to decapitate your Star Wars minifigs to allow for insertion of electronics and battery.

After taking off the head, cut the helmet down a bit to make room for the electronics in the helmet, and use a small tool like a dremel to carve out enough room in the upper and lower body to make room for the battery .

Next, cut a small hole in the back to prepare for insertion of a miniature push button in the top center.

Next, assemble your Joule Thief. A full set of instructions is given at bigclives website above, but its fairly straightforward. Just wind the ferrite bead with 0.15 mm copper wire and connect up the resistor and transistor in the centre. Two wires should be left sticking out to the left to connect up the LED and another two wires left for connecting up the push button and battery.

You then need to embed the button in the back of your Lego Star Wars miifig at the top center of the body.

Finally, place the red film inside the helmet and re-assemble the minifigs. Voila - you now have a customised Star Wars minifigs that will be the envy of all of your friends.