|Tesla Coils are basically 'Self Resonant Air Cored Transformers' which are used to convert High voltages, usually between 6kV and 20kV to ultra high voltages between 500kV and 10mV. Assembly of a Tesla Coil is difficult and Getting it working is even more difficult (I can't comment since mine is incomplete) Before even entertaining the thaught of building one, you should research them THOROUGHLY and start small. Finding a circuit diagram is not even half a percent of the info needed to produce one. I had the circuit diagram 18 months ago, the same day I found out about this hobby. It has taken all this time in research before beginning construction a month or two ago. The most common circuit used is actually very simple but there is a huge amount of variation in design parameters which can mean the difference between good sparks or an Explosion / Fire. The amount of re-adjustment and re-testing involved requires planning and Safety knowledge. It is very easy to slip-up and forget (just once) about the safety requirements, the coil won't be anywhere near as unpredictable as you and it will hurt/kill you if given a chance. That is a big part of the whole Tesla coil/High Voltage culture which (since you are here) you are exploring. Of course, no-one was ever killed as a result of reading about them and that is the best way to decide if coiling is for you. For me Its not about science, its not about art, its not even about free electricity, Its all about
F@#$%#G big sparks using science and art (I do think there is a fair bit of art to the construction since there are no real rules besides physics). If you are interrested, check out www.pupman.com, it has a really brilliant archive of coil information and discussions. Click Below to proceed into my Tesla Coil site and proceed at your own risk.