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Is there any way to change the capacitance on a leyden jar/ bottle capacitor? Answered

I am trying to build a capacitor bank for my tesla coil. I am running two 15 kv transformers in parallel for 120 mah. I was running a bank of 7 .015 mf capacitors with 4 wired in series on each one but they burn out incredibly fast. I need a way to build my own that will either withstand the heavy stress or are simple to replace. Either way they need to be the exact capacitance of my tesla coil.

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alessiof76Best Answer (author)2009-05-16

You can lower the capacity simply removing part of the external plate to the bottle

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crazy coiler (author)alessiof762009-05-18

thankyou, however I tried to run a leyden jar made out of a plastic bottle, and electricity just arced through the bottle, melting it...

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08techgrad (author)2010-02-06

Instead of using air which has a dielectric constant of 1, you could try some thing like paraffin that has a constant of 2.26.  If you REALLY want to be surreptitious, water has a constant of 78, titanium oxides vary from 10-10k!

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lemonie (author)2009-05-16

Do you not want to use a simple air-gap? L

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crazy coiler (author)lemonie2009-05-18

I'm not sure I understand what you mean?

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user

Lemonie means that, instead of a solid dielectric like the glass of the bottle, use two parallel metal plates. The air between them will serve as the capacitor's dielectric. You could easily rig one of the plates so that the distance between them will be adjustable (thereby varying the capacitance).

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user

A better way would be to immerse the two plates in oil - this prevents corona losses and will increase the capacitance.

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PKTraceur (author)2009-05-16

Well, to charge a leyden jar, (tediously, mind you,) get a 2.5 ft piece of PVC pipe. Rub the crap out of it with a cotton/silk cloth. While at the same time, rubbing the PVC, keep moving it over the top terminal. -PKT

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