RE: Capacitor

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Hajdrowski, Leo T." <leo.hajdrowski@xxxxxxx>

Hello Sean,

Thanks for info. I'll put them in series to see if that helps.

Leo

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Tuesday, June 27, 2006 1:43 PM
To: tesla@xxxxxxxxxx
Subject: Re: Capacitor

Original poster: "Sean Taylor" <sstaylor@xxxxxxxxx>

Yes, too much capacitance is bad - for 2 reasons.

First, the NST that you're using is going to have a hard time charging a
capacitor that large sufficiently.  Second, it's going to be hard to
tune the coil with that capacitor - you'll need very few primary turns.
At the very least, I would put the two caps in series so you'll have
0.11uF.  Stil quite a bit too large for that transformer, but closer!

Lastly, I don't know about the suitability of those caps for TC use.
Generally, X-ray caps are DC filter caps only and aren't designed for
the high peak currents that they will see in a TC tank circuit.

Sean Taylor
Urbana, IL


On 6/27/06, Tesla list <tesla@xxxxxxxxxx> wrote:
>Original poster: "Hajdrowski, Leo T." <leo.hajdrowski@xxxxxxx>
>
>Hi All,
>
>One quick question.
>
>I just finished helping my son build a coil:
>
>15 kv, 60 ma nst with full wave rectification Secondary 10.5" x 30"
>#22GA wire Primary 3/8" 10 turns copper tubing flat coil - 1/2" spacing

>between winds 1" spacing between primary and secondary First windings
>of secondary approximately 1" above primary.
>Stationary spark gap with 1/4" spacing
>20 amp variac
>30" dia. Torroid
>(2) .22uf 90KV capacitors in parallel (They came from an X-Ray machine
>and are about 4" dia. X 18" long).
>
>We only get about an 8" spark and no corona.....it doesn't appear to be

>high frequency, more like a step-up xfmr.
>
>Is too much capacitance bad?
>
>Thanks...Leo
>
>