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Myler Capacitor for Tesla coil? Answered


Is this good for a SGTC? im using a flyback transformer powered  with ZVS driver running of 30v. So im thinking of putting 60 of these is series and nothing in parallel. The secondary is 16inch long and 4 inch dia. Flat primary with 7 turns.



Best Answer 4 years ago

They should work, sort of...
Keep in mind that huge amounts of energy are pulsing through them at high frequencies.
For obvious reasons a pulse discharge capacitor would be the prefered option.
The only "small" capacitors I can recommend and know to work just fine are from "WIMA".
They do cost a few cents more than standard but they will tolerate the abuse without too much overheating.
Depending on the capacity you really need I suggest to use the caps in a parallel-series combo.
To get 200nF for the tank.
Use 4 100nF caps parallel, resulting in 400nF.
Make another similar block and connect in series to the first one.
2 400nF blocks in series give 200nF all up.

But you need a tuned system, which means your primary with the tank has to match the resonant frequency of your secondary with the top load.
If they are too far apart you won't be able to tune it just on the primary coil.


Answer 4 years ago

i couldnt find a good site explaining the tuning, But also i dont know the output voltage of the flyback, although i think its approx about 15-20kv because the arc starts to jump at about 1.5cm(a lot of approx). After seeing some coils made with flyback, most of those use 20-50nf cap banks so im hoping to go with that.

Jack A Lopez
Jack A Lopez

4 years ago

I won't comment on the suitability of these capacitors for a Tesla coil design. What follows is mostly trivia.

Mostly I just wanted to let you know they, the parts seller you link to, are spelling that word incorrectly. It is Mylar, with an "a".

It is brand name, so maybe I should be putting that symbol with an "R", for "reserved", in a circle after it, like Mylar(r), or something like that. I have not figured out how to make this editor print that symbol, so I often use "(r)" instead.

The material itself is a kind of PET film, with a thin layer of aluminum metal, on one or both sides. The generic name for Mylar, is BoPET,


Capacitors made from plastic film, including plastics other than PET or BoPET, are broadly called "film capacitors", and there is a Wiki page with this title,


The section of that article titled, "Polyester (PET) film capacitors", mentions some of the properties of film capacitors made with PET, aka Mylar(r) film.

So. Yeah. I have not told you anything specific to your Tesla coil plans, but at least now you know how to know how spell the word "Mylar".

Tell your friends! And please share the video linked below.


This video was made by Dupont, in 1955, and features a guy-in-a-tie, sales-narrator, an acrobat doing flips on a trampoline made of Mylar, another twisting on a "rope" made of Mylar, and a bunch of other goofiness. They even did a little demo (at 5m+30s) for Mylar's electrical properties, using a sheet of it to break the arc of a "Jacob's Ladder" type setup. The guy-in-a-tie puts on some heavy rubber gloves for this demo. Not sure what the competing material that got burned through was. I am guessing it was paper or cardboard.