Re: PFC caps

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "PotLuck by way of Terry Fritz <twftesla-at-qwest-dot-net>" <potluck-at-xmission-dot-com>

Hi Jim,

By the way, I'm using 100uF PFC for a 15/30 NST.

Rick W.
SLC

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, June 13, 2002 11:00 PM
Subject: Re: PFC caps


> Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>
>
>
>
> Tesla list wrote:
> >
> > Original poster: "Steven Ward by way of Terry Fritz
<twftesla-at-qwest-dot-net>"
> <srward16-at-hotmail-dot-com>
> >
> > Hello
> >
> > I am running my coil from a reconditioned NST.  It had to have windings
> > re-wound on the primary, and the core has some small gaps that i could
not
> > fix.  So this means that it draws a bit too much current.  It was a
12000/30
> > unit.  I have removed 10 shunts from each pack of shunts(40 total).  The
> > transformer now draws 7.5+Amps, depending on operation(can raise to
about
> > 8A).  I am interested in power factoring.  I have a few main questions:
> >
> > What size cap do i need?
>
> If you have removed shunts, you have also reduced the "equivalent series
> inductance" that a power factor correction capacitor would be compensating
> for.
>
> To know what size cap you need you need to know what the power factor of
> your transformer is now (in operation...).. You can measure the leakage
> inductance fairly easily by standard transformer measurements (short the
> output, measure the current, etc.)
>
> With that information, you'll have a starting point for correction.
>
>
> But, to get you started, you KNOW that it will need less PFC than an
> unmodified 12kV 30mA transformer would.  Since the original transformer
> probably drew around 3 Amps, a ballpark would be to start with half the
> capacitance you'd use on the 12/30.
> >
> > Who is a good supplier?
>
> >
> > Will PFCing reduce heating of the primary coil?(it gets rather warm)
> PFC might reduce heating of the transformer a bit (less RMS current for
the
> same power out)..
> It won't change the TC primary at all.
> >
> > Is there anything else im missing out on with this whole deal??
> >
>
>
>
>