Re: Commercial cap specs for tesla cap
Subject: Re: Commercial cap specs for tesla cap
From: Terry Fritz <twftesla-at-uswest-dot-net>
Date: Fri, 05 May 2000 19:45:51 -0600
Here is my feeble attempt ;-))
At 10:02 AM 05/03/2000 -0400, you wrote:
>Hello fellow coilers,
>I contacted NWL capacitors for a cap for a tesla coil application. They
>sent me an email that I need to fill out ther cap form. If anyone out
>ther could help me give them the specs they need it would be
>appreciated. this is what they want to know: tolerance
> rated voltage = 15KVAC RMS nominal
> peak current = probably ~1500 amps. If I knew more about the
coil I could get closer...
> rms current = ~25 amps is probably in range. Maybe as high as 50...
> duty cycle = ~1%
> op. temperature = room temp or 25 C
> voltage reversal = Oh yeah!! Full reversal at full rated
voltage and current!! No "wimpy" caps need apply! ;-))
> ringing frequency = I think this would be the fundamental
frequency of your coil. However, they may be after the self resonant
frequency of the cap. "maybe" 2Mhz????????
> maximum Ind. Calculated from the above and the value of the cap.
> design life 100 Hours would probably do it.
> case style what ever is cheapest ;-))
> terminations 3/8 inch brass bolts are nice if that is not going
to push the cost up...
>Im using a 14.4KV/5kva piggy running up to 6-7KVA. They said they
>couldnt build me a cap without all these specs. Im not an engineer so
>Ill need some help.
>Best Regards Jeff KD4LYH
I can't be totally sure about these numbers without knowing more about your
coil and how they define some of these specs. Hopefully this gives you
some idea as to how to respond to them... Unless you need a fairly high
value cap. Perhaps the much more trusty MMC would be the way to go? A BIG
description of your coil's values would help a lot... We could probably
pin these items down to full detail... Tesla coils are some of the meanest
cap applications known so NWL may bail out before taking on the level of
"fun" we like to run caps at ;-)) What value of cap are your looking for?
I have to wonder if MMCs will be cheaper and better...