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Re: Freau's efficiency theory=Success!?



Original poster: "Alexander Rice by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ajjrice-at-yahoo-dot-com>

It's just an idea but in my experience 'wattmeters' do not cope well with
inductive loads as they assume current and voltage to be in phase, for
example if you measure an inductively blalasted strip light with an ordinary
wattmeter you will find that a 20w tube only 'draws' about 15w which kina
violates conservation of energy. I am not trying to belittle the efficency
of this coil i am merely suggesting that the efficency could be due in part
to a lower than reality power reading.

Respectfully

Alexaner Rice
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, June 07, 2001 11:50 PM
Subject: Re: Freau's efficiency theory=Success!


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>
>
> In a message dated 6/6/01 7:14:44 PM Eastern Daylight Time,
tesla-at-pupman-dot-com
> writes:
>
> > Original poster: "R.E.Burnett by way of Terry Fritz
<twftesla-at-qwest-dot-net>"
> <R.
> > E.Burnett-at-newcastle.ac.uk>
> >
> >
> >  Hi John, all,
> >
> >  > I thought that adding PFC would stop the NST's (over-current)
suffering.
>
> >
> >  I believe this is not the case.
>
> Hi Richie,
>
> I see what you're saying.  I had never given it that much thought before.
> (I wonder what other things I haven't given enough thought?)  I guess
> the NST primaries are destined to always be abused in common usage.
> I too like the idea of designing large systems for a good power factor
> without PFC.  I guess the thing with those NST's is to not let them
> get too hot (among other things, ho ho).
>
> Cheers,
> John Freau
>
> --
> >
> >  A PFC capacitor connected across the primary of an NST draws a reactive
> >  current from the supply which is 180 degrees out of phase with the
> >  reactive part of the NST current.  The supply current is the sum of
these
> >  two currents.  So the inductive part of the NST current is cancelled by
> >  the capacitive current drawn by the PFC.
> >
> >  This reduces the overall current drawn from the supply line,  but the
> >  windings of the NST still see the same total current with or without
> >  PFC.  It is only the line current which is reduced by cancelling the
> >  reactive contribution.  However, PFC is still worthwhile as reduced
line
> >  current makes life easier for the Variac, circuit breakers and wiring.
> >
> >  This is one of the reasons why I believe that larger systems should be
> >  designed with high PF in mind from the outset.  A poor power factor in
> >  a large system burdens the transformer and ballast,  and requires a lot
of
> >  PFC capacitance to make a significant improvement in the power factor.
> >
> >                           Cheers,
> >
> >                           -Richie,
> >
>
>


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