Re: PFC unbelievable!

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

Original poster: "Rick Williams by way of Terry Fritz <twftesla-at-qwest-dot-net>" <richardwwilliams-at-earthlink-dot-net>

Hey everyone,
Thanks guys!
Ok, changed it to the primary side of the NST. That's better. :) Before with
the PFC caps at the input of the variac current rose as the variac was
turned down. Now it follows the rise of input voltage.

Without a load and PFC connected the current goes from 0.7 amps loaded to
2.0 amps unloaded. Still quite an improvement over the normal 4.25 amps
without PFC.

Rick W.
Salt Lake City


----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, November 10, 2001 5:53 PM
Subject: Re: PFC unbelievable!


> Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>
>
> Now I realize you posted your schematic.. (didn't scroll all the way down
on
> the message...)
>
> I'd try it with the PFC caps on the load side of the variac.  The
inductance
> that those caps are compensating is the excess leakage inductance from the
> NST. With the PFC caps on the line side of the variac, as the variac is
> reduced down to 0, the effective inductance of the NST is reduced, and you
> wind up with essentially a bunch of caps across the power line (drawing a
> fair number of amps).  There IS some inductance in the variac itself, but
> its effect is fairly small (in comparison to that in the NST).
>
> On the other hand, if it works the way you've got it, why change...
>
>
>
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Saturday, November 10, 2001 11:01 AM
> Subject: PFC unbelievable!
>
>
> > Original poster: "Rick Williams by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <richardwwilliams-at-earthlink-dot-net>
> >
> > Hi List,
> >
> > Got some 12uF 240v run caps from
> <http://www.usamfg-dot-net/>http://www.usamfg-dot-net/
> > for 50 cents each. ( #71932 )
> >
> > Found out 8 of them were optimum, 96uF for one 15/30 NST and a Staco
25amp
> > variac.
> >
> > Current was measured from the wall plug using an AC ammeter.
> > NST output voltage was measured by a high voltage voltmeter (0-40kv).
> >
> > With the variac set to maximum without the PFC current was 4.25 amps,
with
> PFC
> > it dropped to 0.7 amps, 700ma !!!!
> >
> > With the variac set to MINIMUM the current measured 4.20 amps with the
> PFC.
> > Makes sense.
> >
> > NST output current behaved the same with or without the PFC varying
> smoothly
> > with the variac.
> >
> > The schematic:
> >
> >
>
<http://potluck45.homestead-dot-com/files/PFCcaps01.jpg>http://potluck45.homest
> > ead-dot-com/files/PFCcaps01.jpg
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>