I've found this video on the web: http://www.youtube.com/watch?v=TIhPayFBE9c&feature=related and id like to be able to build one myself. But i don't really know how to start with this nor how it works. -The 8 shaped coil is really 8 shaped or just 2 coils bound together? -how do you make the second coil (the one with the light) resonate in the same frequency? -what voltage do you put into the primary coil to make it work? I've looked on the net but can't find anything helpful. Please help me or atleast push me in the right direction.