Re: Paralleling dissimilar NST's

To: tesla-at-pupman-dot-com
Subject: Re: Paralleling dissimilar NST's
From: Ed Phillips <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Fri, 11 Feb 2000 17:18:42 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Tesla List wrote:
> 
> Original Poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>
> 
> I'm not sure I agree that paralleling slightly dissimilar Vout transformers
> will result in losses due to "fighting".  Consider this thought experiment.
> Take the two 14.5 and 15.5 KV 30mA NSTs and wire them in parallel, observing
> correct phasing.  Apply an AC milliampmeter across the outputs, essentially
> shorting them.  Since Vout is now essentially zero, their open-circuit Vout
> difference is no longer significant, but yet their short circuit currents
> would combine to yield 60mA.  Open circuit, their voltages should average
> out to 15.0KV,assuming similar winding resistance.
> 
> Gary Lau
> Waltham, MA USA

	Agree.  I've paralleled a 12 kV and a 15 kV NST here (both 60 ma) and
the combo worked just fine.  No "fighting".  At short-circuit both
deliver the same current.  As the capacitor is charged the division of
current will change until, if the gap spacing permits it, the voltage is
betweem 12 and 15 kV, where the current will be flowing from the higher
voltage transformer to the lower voltage transformer.  Most of the
energy will have been delivered to the capacitor before that.

Ed