Re: New 8 second long 550 kV Power Arc

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

Original poster: John Keith <jskeith-at-interaccess-dot-com> 

Hi Folks,

    As a welder and a builder of power supplies, I have also done a lot of
experimentation in this area. A 200 Amp welder actually produces about 4-6
KVA due to the actual arc voltage being quite low, but your point is well
taken. The reason you get a long arc when quickly withdrawing the rod is
that the sudden decrease in current causes a corresponding brief
high-voltage pulse from the transformer. The xformer in an arc welder has a
high leakage reactance and behaves like a normal xformer in series with an
inductor. That's also why they are useful as ballasts for pigs;-)

Regards,
John K.


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, December 15, 2003 12:57 PM
Subject: Re: New 8 second long 550 kV Power Arc


 > Original poster: DRIEBEN-at-midsouth.rr-dot-com
 >
 > Mike,
 >
 > It seems that you have done some experimentation in this area. I would
think
 > that the idea of increasing the voltage with the amperage would apply too,
in
 > this case. For example , a 200+ amp arc welder will easily put out 10 kVA
or
 > more but I don't think your going to be able to pull a 3 ft. arc with your
 > welding rod simply because the voltage is way too low (<50 volts). I have
 > pulled out 6 to 8" of arc in this manor, though, by touching the welding
 > rod to the work surface and quickly pulling the rod away ;^)
 >
 > It would be interesting to see the results of extensive tests in this
area.
 > I agree, someone needs to get Bill Gates personally interested in HV ;^)
 >
 > David Rieben
 >
 > ----- Original Message -----
 > From: Tesla list <tesla-at-pupman-dot-com>
 > Date: Monday, December 15, 2003 9:01 am
 > Subject: Re: New 8 second long 550 kV Power Arc
 >
 >  > Original poster: "RIAA/MPAA's Worst Nightmare"
 >  > <mike.marcum-at-zoomtown-dot-com>
 >  >
 >  > Not sure about MVA levels (anyone know one of Bill Gates' phone
 >  > numbers so I
 >  > can test this?), but everything I've done from a  230 va obit to
 >  > 50 kVA
 >  > (actually was closer to 55 before the breakers popped and the
 >  > utility and
 >  > neighborhood complained) the 3.3-3.5 kVA/foot rule applies. In
 >  > think the
 >  > catch is to increase voltage along with current. With a 14.4 kv pig,
 >  > increasing current much beyond an amp actually stops the arc from
 >  > climbingas high up the ladder. Not sure, but seems to be blown out
 >  > with its own
 >  > magnetic field before long once it starts. I got around 17 feet
 >  > with 69 kv,
 >  > ~800mA. Unfortunately I sold the pigs when I moved from Stanberry
 >  > MO to here
 >  > in Cincinnati a few years ago. (The (2) 34.5 kv 25 kvA pigs
 >  > weighed over
 >  > 1000 lbs each, not something easy and cheap to move if you have no
 >  > garage to
 >  > put them in). I'm guessing as long as  the voltage/current ratio
 >  > is around
 >  > 1A/50kv or so and a huge air mass was perfectly still (unlikely when
 >  > measured in  miles) it's close to linear.
 >
 >