Re: caps

To: tesla-at-pupman-dot-com
Subject: Re: caps
From: "Ed Phillips" <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Sun, 28 May 2000 11:26:10 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Tesla List wrote:
> 
> Original Poster: Toxandale-at-SPP-dot-org
> 
> I understand you can series electrolytic caps in "mirrored"  pairs to
> get an AC acceptable "non-polar" usage with these types of caps (tie the
> positive ends together in each pair to get one ac cap). This is theory,
> and I have not actually practiced it.
> 
> Terry

	That is correct, and the capacitor so connected will indeed work. 
HOWEVER the losses will be quite high and the thing cannot stand running
at a current of a few amps.  This is the configuration for electrolytic
"motor starting capacitors", which typically have capacitance ratings of
something like "70-120 ufd", indicating that no one is quite sure what
the capacitance really is.  So, suitable for intermittent duty (few
seconds on at a time) in 60 cycle service, but totally unsuitable for
use in PFC operation.  As for for tank capacitors for TC primaries,
forget it completely!

Ed