# Re: NST Study results

```Thanks Terry!  So that would mean that I would need about 300mf of PFC
for my coil, give or take a few mf, does that sound proper?  Would a bank
of mercury lamp ballast capacitors work?  They are in a metal can and are
22.5mf each, and are rated at 280vac.  I would parallel them to get the
desired capacitance using 1/4" quick connect crimp fittings.  I have 14
of them and can realize a bank of 315mf of PFC.  Do you think this is
worth trying?  Thank you.   Al.

On Sun, 10 Sep 2000 12:32:35 -0600 "Tesla list" <tesla-at-pupman-dot-com>
writes:
> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
> Hi Al,
>
> 	In general, they do add in a linear way.  So if you double
> the NSTs, you
> double the PFC capacitance.  However, that assumes that the primary
> capacitance doubles too.  If you leave the primary cap the same,
> then two
> transformers will be driving that primary cap value.  So you would
> use the
> chart number for 1/2 the Cprimary.
>
> 	Just think of it as two completely separate primaries that
> you are
> paralleling up.
>
> In general, Adding PFC caps will cut the current draw by about 1/2.
> Thus,
> you can run twice the NST on the same variac and AC line fuse.
>
> Cheers,
>
> 	Terry
>
>
> At 04:12 PM 9/10/00 -0400, you wrote:
> >Very nice Terry!  Thank you for compiling all this data!  I shall
> now use
> >it to apply PFC to my coil.  Would it hold true then that two 15kv
> -at-
> >60ma. neons would need roughly 340 to 400 mf of PFC (meaning, using
> your
> >chart data for current and pfc for one neon, would it hold true
> that the
> >pfc needed would be double for two neons?).  Al.
> >
> >On Sat, 09 Sep 2000 22:11:59 -0600 "Tesla list" <tesla-at-pupman-dot-com>
> >writes:
> >> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
> >>
> >> Hi All,
> >>
> >> I have posted the results (so far) of my NST study at:
> >>
> >> http://216.160.168.190/TeslaCoils/Misc/NSTStudy/NSTStudy.htm
> >>
> >> The main site is 'now' at:
> >> http://216.160.168.190/TeslaCoils/TeslaCoils.htm
> >> Note that this site's address occasionally changes (like it did
> >> Thursday ;-))
> >>
> snip...
>
>

```