Re: plastic capacitors???

To: tesla-at-poodle.pupman-dot-com
Subject: Re: plastic capacitors???
From: Tesla List <tesla-at-stic-dot-net>
Date: Sun, 30 Mar 1997 17:57:14 -0600
Approved: tesla-at-stic-dot-net

Subject: 
        Re: plastic capacitors???
  Date: 
        Sun, 30 Mar 1997 11:36:41 -0500 (EST)
  From: 
        richard hull <rhull-at-richmond.infi-dot-net>
    To: 
        Tesla List <tesla-at-pupman-dot-com>


At 07:43 PM 3/29/97 -0600, you wrote:
>
>
>I was just at a local swap meet and found a big pile of "plastic"
>capacitors - 
>these are orange oil filled cylinders with screw terminals at each end. 
>I 
>bought one rated 14KV, .001 microfarads to play with. The vendor has a
>fair 
>amount of .25 at 5KV units.
>
>1. are these useful for tesla coil work

Nope they are not!  These are Mylars and are very high loss units and
can
explode with to much input energy in time.  We have specifically
mentioned
these in the past. R. Hull

snip
>
>3. I bought some 7500 v, .1 microfarad oil filled capacitors (sprague)
>with 
>metal cases - I figured on putting 6 in series to use with the small
>coil I'm 
>building - comments???  (the vendor said he had a few of these left
>too).

If those spragues are paper construction, yes, they can be used safely
and
to advantage in coil work, although they will incurr some losses.  oil
impregnated paper caps used to be the prime high energy storage cap of
yesteryear.  Today, they are third rate at best, but much better than
those
orange mylars. R. Hull
>
>4. I found a guy who said he had a .8 microfard 45,000 volt capacitor -
>I 
>didn't ask a price.

Still too big for Tesla work, but might make a nice exploding wire cap.
R. Hull
>
>