Re: PFC unbelievable!

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

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
>
>
>
>
>
>
>
>