Re: Capacitor in question

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Capacitor in question
From: Tesla List <tesla-at-stic-dot-net>
Date: Fri, 8 Aug 1997 08:06:12 -0500
Approved: tesla-at-stic-dot-net

From: 	Edward J. Wingate[SMTP:ewing7-at-frontiernet-dot-net]
Reply To: 	ewing7-at-frontiernet-dot-net
Sent: 	Thursday, August 07, 1997 5:27 PM
To: 	Tesla List
Subject: 	Re: Capacitor in question

Tesla List wrote:
> 
> From:   Richard Staron[SMTP:rstaron-at-widow.aracnet-dot-net]
> Reply To:       rstaron-at-widow.aracnet-dot-net
> Sent:   Tuesday, August 05, 1997 5:35 PM
> To:     tesla-at-pupman-dot-com
> Subject:        Capacitor in question
> 
> Hi and thanks for reading my request.
> 
> I have just picked up some capacitors, 3 to be exact from one
> of our local surplus places and I was wondering whether these
> could be used in a small coil.  The coil that I am building is
> 4" Diam x 18 long being driven by a 15kv -at- 30 ma neon transformer.
> I was hoping to put these in series but before I made up a support
> for them, I thought I had better ask the experts if anyone knew
> if they were any good or not.
> 
> The capacitors in question are described as follows:
> 
>    5.75" long x 1.25" diam
>    Body is brown in colour with a screw terminals produding one from
> each end.
> 
>    They are made by CONDENSER PRODUCTS
>    .0125 UFD -at- 25000 VDCW
>    Model number KMOB 123-25MN
> 
>    There is also another number printed on the body as 1210-107.
> 
> If anyone knows whether these would work or not, a reply would greatly
> be appreciated.
> 
> Regards
> 
> Richard

Richard,

According to my Condenser Products data sheets the capacitors you have
are:

KM = kraft paper and mylar(polyester)
O  = mineral oil
B  = bakelite ( paper phenolic ) tube


Mylar is not a very good dielectric for Tesla use and while these caps
may work for limited use in Tesla service they are very "lossy" and will
get hot quickly and may not last very long either. Now, if the first two
leters were KN, that would denote kraft paper and polypropylene which is
one of the best dielectrics for Tesla use, just the opposite of mylar.
If you see any more Condenser Products caps at your local surplus dealer
look for the KN or just an N. The N denotes polypropylene only, with no
kraft paper.

Safe coiling,

Ed Wingate