RE: Thanks - Re: Saturable Reactor Ballast from MOT's

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

As I understand things, you'd basically be relying on
the LV windings of the series MOTs to act like a
voltage divider, perfectly dividing the 240V.  If it
was perfectly divided and remained so even with
loaded, you'd be ok.  If not (e.g., because of
differing impedances--a reasonable thing to expect),
then this might translate into wildly different
voltages on the HV side.  These, in turn, would no
longer cancel out, and you'd fry your control (and
maybe yourself!)

So if you have a pig with a neutral lead, I'd prefer
to put a pair on each 120V leg and just run the same
control to both.  That's what I plan to do, at least.
I'll certainly report back with my success (or lack
thereof).

Regards,
Aaron, N7OE


--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "Alex Kardash"
> <voltamp1@xxxxxxxxxxx>
>
> I should have also asked:  How come you can't make a
> 240V ballast by
> just putting the primaries of MOTs in series instead
> of parallel?
>
> Safe TC'ing,
> -Alex
>
> >From: "Tesla list" <tesla@xxxxxxxxxx>
> >To: tesla@xxxxxxxxxx
> >Subject: Thanks - Re: Saturable Reactor Ballast
> from MOT's
> >Date: Fri, 24 Feb 2006 21:05:31 -0700
> >
> >Original poster: "Alex Kardash"
> <voltamp1@xxxxxxxxxxx>
> >
> >We should congratulate Aaron also, from whom the
> recipe for a
> >dual-MOT ballast originated week on hvlist
> (actually, Carl did
> >mention that below, but I thought I should point it
> out again for
> >posterity's sake :))
> >
>
>http://www.pupman.com/hvlistarchives/2006/Feb/msg00003.html
> >
> >Anyway, thanks to both Carl and Aaron for giving me
> something to do
> >tonight :D  I just tried this with two *similar*
> MOTs, having the
> >same rated voltage and power capacity, and it
> appeared to work out
> >ok for a relatively small load (about 3A).
> Unfortunately, I'm an
> >NST coiler and hadn't done anything with these MOTs
> until tonight,
> >so I'm struggling to find a larger load to play
> with!  Where's a
> >third MOT when you need one?!  Time to go to eBay,
> methinks...
> >
> >Safe TC'ing,
> >-Alex
> >
> >--- Tesla list <tesla@xxxxxxxxxx> wrote:
> >
> >>Original poster: Finn Hammer <f-h@xxxx>
> >>
> >>Carl,
> >>
> >>Congratulations, this may be the most important
> >>discovery in quite some time.
> >>
> >>I may be wrong, but from the schematic, it would
> appear that you
> >>have the secondaries wired in parallel pairs of
> opposing series, as
> >>you describe.
> >>However, since the primaries are wired in pairs of
> opposing
> >>parallel, it would appear to me, that the effect
> is canseled, and
> >>you would in fact get voltage on the
> secondaries/controll windings.
> >>Therefore I suggest that the schematic does not
> faithfully record
> >>the setup as you describe.
> >>Perhaps this is more what is intended?
> >>http://home5.inet.tele.dk/f-hammer/satur.jpeg
> >>
> >>However, a very clever idea. I have never seen
> anyone taking the
> >>controll winding out on 2 separate
> >>cores.
> >>
> >>Cheers, Finn Hammer
>
>
>