RE: Power factor correction

["Tesla list" <tesla@xxxxxxxxxx>]

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

(gettin' a bit OT here, but...)

Jacob's ladders are mostly about current, not voltage.
 You need current to generate plasma/heat, and heat to
make the plasma/arc rise.  More current will permit
the arc to "stretch" longer.  If you have mega-high
voltage but virtually no current, then the legs of
your Jacob's ladder will be far apart and nearly
parallel, since there will be little "stretching"
involved, and this in turn will probably yield
inconsistent performance (arc frequently giving up and
restarting at the bottom before it reaches the top,
etc.)

NSTs make ok Jacob's ladders.  A 15/30 can produce an
arc that self-starts at under an inch but may stretch
to a couple of inches before breaking and restarting
at the bottom of the ladder.  Fun, easy to build, and
(relatively) safe.  Still, the lack of current in the
NST case can make ladder peformance inconsistent, and
placing the ladder in some kind of enclosure may be
necessary to allow convection (and thereby the arc) to
be more consistent.

A typical 14.4kV pig is about like a 15/30 for
voltage, but can deliver several amps!  This has an
enormous influence on ladder performance; the arc can
easily be made to stretch to a foot or more!  Here's a
picture of what that might look like (from some
Googling--not sure whose this is, really):

http://www.flickr.com/photos/tesla1000/page3/

The picture has "15kVA" above it, and "14,400 volts, 2
amps" below it, which doesn't quite add up!!  The
latter would be about 30kVA, not 15kVA, but
whatever...  Note, too, that the arc is a totally
opaque white flame.  There is a big difference between
a Jacob's ladder running ~15kV at 30ma and 2A!!!

BUT (!!!): Beware the Voltage Spikes of Doom!  Running
big Jacob's ladders is a good way to kill stuff in
your house just as surely as a lot of RF from a TC,
maybe worse!  Put some caps across the LV side of the
tranny to eat these up or you could really have a mess
on your hands.

Regards,
Aaron, N7OE

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

> Original poster: Skip Malley <skip@xxxxxxxxxxxxxxx>
>
> My suggestion was 10KV 30 mA was 300 Watts not 3000
> Watts.
>
> You are talking about 900 watts, not 9,000 watts
> with 15KV 60MA as
> mentioned by another reply.  The emailer that I
> replied to seems to
> be talking about a transformer that are many times
> the voltage that
> Tesla coils and Jacob's ladders would tend to use
> You don't do
> Jacob's ladders with X-Ray transformers DO YOU?  Am
> I missing
> something?  Can we get a confirmation of this from
> either Dr. R., or Chip?
>
> I would certainly love to see a large Jacob's
> Ladder.  I would guess
> that bigger only sounds larger.
>
> Sounds good to me.
>
> Skip
>
>  > >I was making a Jacob's ladder with a
> dialed-down/ballasted x-ray
>  > >transformer (83v 41A in atm, limited by the 30A
> breaker and dry atm
>  > >'till I build a tank and vacuum it, ebay special
> so was shipped ups
>  > >dry to save shipping). Close to 38kV and 90 mA
> out (making a
>  > >mean-looking 12" arc). I wanted to power factor
> correct this so I
>  > >can pull more current without popping the
> breaker (or frying my 20A
>  > >variac). What I don't know is what the starting
> pf is without
>  > >measuring it (good pf DMM's I've seen are
> $250+). Most nst's use .5
>  > >as a rule of thumb for correcting those. Could
> this setup be
>  > >considered as a big nst? If so I think I need
> 1526uF that won't
>  > >change as the current/voltage go up as long as
> the ballast stays the
>  > >same (unless I goofed on the math somewhere).
>
>
> At 12:06 AM 6/21/2006, you wrote:
>
> >He is not talking "modest"
> >
> >Your Jacobs Ladder makes a nice bzzzzzzrt,
> bzzzzzzrt, bzzzzzzrt sound
> >(at 3,000 Watts) while I bet that his sounds like a
> large wolverine in
> >heat. I have one from a 15KV 60MA (9,000 Watts)
> neon transformer that
> >sounds wonderful and I can only imagine what
> something running at 34KW
> >would be like.
>
>
>
>