[Prev][Next][Index][Thread]
Re: (Barry Vs. Fr.Tom) Differing advice on cap. rating.
From: Thomas McGahee[SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent: Monday, November 24, 1997 6:49 AM
To: Tesla List
Subject: Re: (Barry Vs. Fr.Tom) Differing advice on cap. rating.
>
> From: Joshua Resnick[SMTP:seraphim-at-WPI.EDU]
> Sent: Sunday, November 23, 1997 2:55 PM
> To: Tesla List
> Subject: (Barry Vs. Fr.Tom) Differing advice on cap. rating.
>
>
> Barry, Fr.Tom, All,
>
> I recently asked fellow coilers what sized caps they used with two H&R
> transformers in series.
> My calculations say .079uf and so does Fr. Tom. yet you (Barry) used .04
> uf rated at 30 kV DC
> for the task.
> I realize the coil will work at lower ratings but which value is more
> desirable, one that draws the most
> possible current from the transformer or one of lower rating?
> Also 30 kV DC means half that rating AC, so isn't that really pushing
> the caps. voltage rating?
> Have you ever had one of these cap blow?
>
> In addition, how much does one .01uf -at- 30 kV DC cost from CSI?
>
> Thanks for the advice from both of you, I just want to get the biggest
> bang for my buck.
> (and that's what all this is about anyway, right?)
>
Joshua,
The value I gave you is based on matching the cap and transformer.
When using this particular method of cap selection you are seeking
to optimize available power. You do *not* have to optimize
available power unless you find this desireable. There is
absolutely nothing wrong with using caps of a lower capacitance
value. Also, please notice that optimization such as this then
drives some of the other design parameters. Some people prefer
to choose the frequency of operation first. or some other
starting point. Such as what size secondary they can afford. Or
what size cap they can afford. Or have on hand. Or whatever.
All of the above are valid reasons for going this way or that.
There is no *one* way to do it. As you mentioned, if you want the
most bang for the buck, matching the cap and transformer can be a
useful technique. Another useful technique is to use a smaller
cap and a higher Break Per Second rate. That, of course, usually
means a variable speed rotary spark gap. You makes your choices
and then go forward. That is half the fun of it, isn't it?
As to the .01 caps, I don't have info on the CSI ones, but I dug
this out of my "supplies info" files.
---------- Forwarded message ----------
Date: Mon, 20 Oct 1997 15:37:25 -0700
From: "Dale F. Pfaffle" <pfaffle-at-tele-net-dot-net>
To: tesla-at-pupman-dot-com
Subject: Capacitors
Mad Coiler and anyone else:
Fair Radio Sales contact is Phil at fairadio-at-wcoil-dot-com .
The capacitors p/n KM14-1000-10 are $95 each and are 5" x 10" x 2.5" with
#12 studs. 100kv at .01uF......
Dale in Nevada.
Hope this helps,
Fr. Tom McGahee