Applying Maths

Doing math when making a Tesla Coil is very important as if you do your calculations right you can dramatically improve the performance of it by only spending a few more pounds. The great thing is that there is a program that will do all the math you need instantly  All you need to do is add some information of you electric components and it will tell you what you need to do to get the best output from what you have got. First thing first you need to decide what transformer voltage you are using.

Transformer

6000v or 6kv, 10 000v, 12 000v, 15 000v. These are the most used rating of neon sign transformers. I am only using a 6000v one because I am using the math to improve my tesla so i dont need to spend more money on expensive, bigger NST's. The more voltage you have in the transformer though the bigger the output spark. Also the current for these is only between 20 - 60MA so they wont kill easily. They do have the capability to kill you but only if you work for it. I will go more into safety later.

Secondary Coil

Now you need to decide on the size of the tube your magnet wire will be wrapped around. I am using a 10cm diameter and 50cm long cardboard poster tube. I will warp on 45cm down it so I have some space to work with. I also will be using this wire for my secondary.

http://www.ebay.co.uk/itm/ENAMELLED-WIRE-24-SWG-23-AWG-x-1-1-lbs-MAGNET-WIRE-/370769671928?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item56539836f8&_uhb=1

If your coil is smaller or bigger than mine buy more or less of the wire. You do not need to change the wire type as it should work for all Tesla Coils. May I just note that if you did not know the magnet wire is only conductive INSIDE the wire. There is actually a small coating of insulater on the wire so if you need to connect the ends of the wire to something else, sandpaper the end of it.

Primary Coil

The primary coil wire only has to be a conductive, flexible string of some kind. You can use a wire or like me, 5m of  flexible copper tubing found here:

http://www.ebay.co.uk/itm/NEW-4mm-microbore-copper-plumbing-pipe-tube-x-1-Metre-/110522134268?pt=UK_DIY_Materials_Plumbing_MJ&hash=item19bba1eefc

Doing the Math

Now that you have your measurements sorted you can go and download the program "Tesla Coil CAD" for free online. Just enter all your measurements and voltages and on the main screen you should see lots of text. In this text it will tell you the two main thing you need to know. Where to tap and the intended capacitance. These two measurements need to be implemented in your Tesla Coil for it to work as max efficiency.

Tapping is just basically how many turns you need to make the primary coil be. You need to get this right as too few turns will make the primary circuit under resonance but to many will result in over resonance. The primary and secondary circuits need to be in the same resonance then they will resonate and be efficient. If you dont understand resonance you need to look it up. If you are using my rating tap between the 6th and 7th turn.

Capacitance will be found under the Neon Transformer / Primary Capacitor Matching tab. There will be a number ending in uF. This is a measure of the capacitance needed to allow the primary circuit to be in good resonance with the secondary circuit. If you are using my ratings e.g 6000v transformer, 50cm long secondary then just use this capacitance: 0.0159uF. To meet this capacitance you either need to buy a capacitor with as high voltage as the peek voltage (tell you how to work out in the next step) and the same capacitance as the CAD program has worked out. Or you can make a MMC (Multi Mini Capacitor) which is a bank of small capacitors that will do the same job as a big one. Making an MMC is the easyest way and they way that I am going to do it.

Read on for : More math (Yey) making a capacitor bank and finally buying all the stuff you need now that you know the rating you need.