types of capacitors to use in tesla coil?

Question

which type of capacitors should i use in my tesla coil
i need a primary capacitor of 6.4 nf and 15000v so im thinking of connecting 15 polyester cap in one string each of 0.1uf and 1000v
will it work? and is it better to use the electrolyte ones or are the polyester capacitors better???

Answer 1

You cannot connect capacitors in series to increase the voltage rating. What will happen is that one cap will arc over, putting more stress on the next one, causing it to arc over and so on until all capacitors are destroyed (in a couple of milliseconds tops). For a Tesla coil you also need low esr and high peak current, which your polyester caps will also not provide.



Electrolytics are out of the question - they are only good for DC, and the esr is WAY too high for this.



Either make your own cap out of window glass and aluminum foil, or buy a cap that is rated for the job from Maxwell. A type 37633 will do the job. Costs around one bazillion dollars, delivery time is months and months and months. You might also find something at a surplus store.

Answer 2

Steven is likely correct. An 8 microfarad capacitor rated 100,000 volts would weigh tons so a much lower capacitance is needed on the high voltage side and probably on the low voltage side, about 0.05 micro farads. Neil

Answer 3

I made a tesla coil in 8th grade for science fair and I used a 4"x4" sheet of glass with aluminum foil on both sides. It worked great!