Re: Plastic Caps of Chicago

To: tesla-at-pupman-dot-com
Subject: Re: Plastic Caps of Chicago
From: "Robert W. Stephens" <rwstephens-at-ptbo.igs-dot-net>
Date: Sun, 1 Sep 1996 22:22:09 -0500
>>From richard.craven-at-mkbbs.co.ukSun Sep  1 14:51:20 1996
>Date: Sat, 31 Aug 96 17:14 +0000
>From: richard.craven-at-mkbbs.co.uk
>To: TESLA-at-pupman-dot-com
>Subject: Plastic Caps of Chicago


>I have a question regarding some cheap caps I am in a position to buy. 
>As described to me over the 'phone, they are manufactured by Plastic 
>Capacitors Ltd, Chicago, and are type OLN, 40pF at 20kV dc.

>They are in cylindrical plastic cases a foot long by a few inches in 
>diameter; they are described as being of extended foil construction and 
>have threaded studs.

>I expect they are filter caps and the extended foil construction is in 
>terms of low self-L rather than high current construction in this case: 
>does anyone know a FAX number for the company, or can anyone tell me 
>anything about the caps?


>Thanks in anticipation,



>Richard Craven, Malvern, England.
>---
> CMPQwk #1.42 UNREGISTERED EVALUATION COPY

Richard,

I have a recent complete catalogue and sales package from Plastic 
Capacitors Inc., of Chicago and it does not list a type OLN capacitor. 
I suspect these are obsolete types.  It does list a Type series OF 
which are a tubular, extended foil plastic dielectric (probably 
mylar) in super pure mineral oil designed for DC filter applications. 
I am using a bank of 16 of these (0.1 mfd-at- 5000 VDC) in a small coil
system in two  series banks of 8 (for 40 KVDC) in  parallel for a total of 0.025 
mfd -at- 40 KVDC.  They work fairly well, but get warm.  I limit run time to 30
or so seconds.  I hit them with 10 KVAC.

They appear to be the same animal (a copy) of the Glass-Mike capacitor
made by Condenser Products in Florida.

The contact info for Plastic Caps is:

2623 N. Pulaski Road
Chicago, IL 60639-2190
USA
Telephone 312-489-0496
Fax             312-489-0496

The Vice President is Tom Brown, I've talked with him on numerous 
occassions and he seems like a nice fellow,  very willing to be 
helpful.

You say they are only 40 pF?  You are going to require 200 of these 
for a 900 watt neon powered system (to achieve 0.008 mfd), and at a foot long
by a few inches in diameter each, this bank will fill your garage.  They 
better be  -really-  cheap to be worthwhile.  Did you perhaps make a 
typo on the value as described?

By the way, That was a really well done post the other day about Q 
and reversal killing of capacitor lifetimes!

Regards, rwstephens