Re: Pole Pig Construction

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

Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-lists.symmetric-dot-net>

You can connect them any of several ways.

1) tie all cores to ground. The outer transformer see 1/2 peak output
voltage minus one transformer acorss the space designed to witstand zero
volts. This woudl be there the secondardy is wround on the core.

2) float all the cores and possible reduce some stress. High voltage is now
spread across the spacing between the primary and secondary. If the high
voltage side shorts ot th primary, big deal. you will not get kV to flow
back into the outlet.

3) Leave one transfomer alone and leave it the secondary grounded to the
core cascade then series the rest of the transformer in an attempt to get
ground and (volts * number of transfomers). Now you have really large
stresses on the higher voltage transformers, probably really bad. On the
othr hand, your tesla coil has only one high voltage lead on the primary to
worry around. Let's assume the cores are floating on the rest of the
transformers.

4) same as above but with cores tied together, which is ground. This is just
as bad.

As I see it, 1) and 2) make the most sense, while still probably prone to
failure. Then of course, if you have infinite free transfomers, who cares.

KEN

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, August 18, 2002 12:50 PM
Subject: RE: Pole Pig Construction


> Original poster: "Dave Hartwick by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <ddhartwick-at-earthlink-dot-net>
>
> Ken,
> I'm not seeing this. How can both outer xfmrs see a 14 kV potential in the
> ungrounded config? This implies a total output of 28 kV. What are the
> physics?
>
> I really must be missing something obvious, but the old brain isn't seeing
> it.
> Dave
>
>
>
>
>
> > Original poster: "Dave Hartwick by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <ddhartwick-at-earthlink-dot-net>
> >
> > What is the purpose of grounding the center xfmr's?? Safety? I've seen
> this
> > recommended in more than one MOT PSU schematic.
> >
> > Maybe I'm missing something obvious.
>
> If the secondaries all are just connected in series you have the full
> voltage of stress on the "higher" voltage transformer. They were not
> designed for handle say 14kV from the secondary winding to the primary, or
> core. If you ground the center your stresses are only 7kV. This is the
same
> principle as in a neon sign transformer.
>
> KEN
>
> >
> > Dave H
> >
> >
> >
> > you have to find a way to isolate the cores and primary windings from
each
> > other if you connect them in series to acheive your expected output
> voltage.
> > Say you wnt around 15kV from 2kV transformers. That's a string of 7. If
> you
> > ground the center, you still have 7kV across the primary windings to the
> > output on the "outer" two transfomers. It seems some insulate them with
> oil,
> > which is really messy and does not sounds too portable.
> >
> > KEN
> >
> > ----- Original Message -----
> > From: "Tesla list" <tesla-at-pupman-dot-com>
> > To: <tesla-at-pupman-dot-com>
> > Sent: Saturday, August 17, 2002 11:42 AM
> > Subject: Re: Pole Pig Construction
> >
> >
> > > Original poster: "Daniel McCauley by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>
> > >
> > >
> > > Why not look into using MOTs (microwave oven transformers).  They're
> dirt
> > > cheap, readily available (even if purchased new), and would be MUCH
> easier
> > > than actually winding and building your own pig.  Thats what i'm going
> to
> > > do.
> > > Dan
> > >
> > >
> > > > I've been after a pig well over a year now. it seems no one in the
> area
> > of
> > > > maryland is willing to cooperate with me unless i have $1000 to blow
> or
> > am
> > > > a business. i was searching around the web and came across 2
websites
> > > > (which i dont have the urls for) where people have made their own.
> > > >
> > > > I am quite interested in building my own if my search does not yeild
> > > > results int he new few days. however, this type of transformer
design
> is
> > > > not all clear to me and the two wesites constructed the pigs
> > differently.
> > > >
> > > > would anyone care to help me figure out how to design a pig? perhaps
> > about
> > > > 5kva?
> > > >
> > > > -matt
> > > >
> > > >
> > > >
> >
> >
> >
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