On 3 Apr 2006 01:33:15 -0700, Winfield Hill wrote:
DoN. Nichols wrote...

According to Ignoramus24006 :
Bert, I have been trying to find contact info on Maxwell labs to get
more in depth info on these capacitors, such as how many discharges
they are rated for, max current etc. I noticed on your page that you
mention Maxwell caps, do you happen to have any better info on them or
how to find out?

First item in a Google search for "Maxwell Labs" comes out as:

http://www.maxwell.com/

They are now "Maxwell Technologies", but that is a minor change.

Right name, wrong company. Through the miracle of modern corporate
buyouts, asset transfers, and whatnot, the Maxwell capacitor guys
and their products are now at General Atomics Energy Products in
San Diego. http://www.gaep.com/contact-us.html The fellows there
are very friendly and kindly sent me a FAX of the detailed datasheet
for my Maxwell #33504 100uF 10kV capacitors, a few years ago, even
though they're no longer manufactured. They apparently have file
cabinets filled with design info and datasheets, and brains filled
with experience and corporate history.

General Atomics Energy Products
General Atomics Electronic Systems, Inc.
4949 Greencraig Lane, San Diego, CA 92123
Phone: 858-522-8400 Fax: 858-522-8401

They also have a pile of useful application notes as online pdfs,
http://www.gaep.com/technical-bulletins.html One of these notes,
http://www.gaep.com/tech-bulletins/h...capacitors.pdf
has a list of HV pulsed capacitors they made dating back to 1980.

One issue that hasn't been brought up is operating degradation and
pulsed-capacitor lifetime. These fellows do wear out, and the GAE,
formerly-Maxwell, folks provide detailed information so users can
estimate the remaining life in a HV pulse capacitor, and replace
it before there's trouble, e.g., Capacitor Engineering Bulletin
96-004, "The Effect of Reversal on Capacitor Life"
http://www.gaep.com/tech-bulletins/voltage-reversal.pdf

What happens in a government lab when a capacitor is removed from
service? I've seen large caps sitting over in a corner, considered
not good enough to place back into routine service, but not bad
enough to throw away either. "Could I have one of those?" I asked,
when on an open-house tour. "Probably," was the answer. So, when
we buy these big fellows on eBay, it's likely they aren't new and
unused, with a full life ahead of them. Another reason for caution.



Thanks Win and DoN. I appreciate you clearing up the corporate
issue. I will print out these PDFs tonight and will check out that
procedure (gotta leave for work now).

i