Re: Stupid question

To: tesla-at-PUPMAN-dot-com
Subject: Re: Stupid question
From: Alex Crow <user-at-alexcrow.clara-dot-net> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Fri, 30 Apr 1999 20:55:22 -0600
Approved: twf-at-verinet-dot-com

Christopher

Yes, it's volts*amps. However in the case of neon sign transfomers, if you
are getting 1kW out (eg 10,000V at 0.1A) your mains input current *will* be
greater than you expect ie 1000/240 for a 240V input to the primary. This
is because of the inductance of the transformer, which will mean that the
current waveform is partly "out of phase" with the voltage waveform. Some
current is effectively being 'wasted' by this inductance - this (so-called
'imaginary' current, but it's there and measurable all the same) part of it
does not contribute to the rated power. You may find with NSTs that the
current input is maybe twice what you expect!

You can correct this with 'power factor correction capacitors' connected
directly across your NST primary. They tune out (or nearly tune out) the
inductance of your transformer and thus reduce this 'imaginary' component
and reduce the current input, increasing efficiency.

Alex Crow

Tesla List wrote:

> Original Poster: Christopher Michaelis <cmichael-at-xmission-dot-com>
>
> I've got a stupid question, since I'm young. :)
> How do I figure out watts? I thought it was volts*amps, but that doesn't
> look like it's right...
>
> Thanks