RE: New Ballast

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

Original poster: "David Dean by way of Terry Fritz <twftesla-at-qwest-dot-net>" <deano-at-corridor-dot-net>

Hi Greg,

Congratulations on the welder. It sounds very much like the one I have in
the back. I don't know who made it or anything else about it, a very long
time ago when dad brought it home I got the impression it came from J.C.
Penny. That was many years ago. I have always been able to weld, at least
decently, with the old welder Dad had (it is at his house now, I don't know
how made it either, but it is very similar to a Lincoln with the switch and
taps for the electrode cable) and also with the Airco Generator welder. But
the junky little cracker box was useless to me until I built a fire truck
from the ground up and had to buy a book to learn how to weld. After I
figured out that I was holding the rod in the wrong direction, welding came
easy. Now I can weld anything, even plastics, (I learned how to do that from
_this_ list_ (by the way, thanks!)) like a pro, even was a pro for a (short)
while, and am called on by some to do their welding only because their life
depends on it and the won't trust anyone else. I don't do a lot of welding,
(am very sensitive to UV) but do get called upon to do some things from time
to time. I used the (JCP I think) as the first inductive ballast for my pig
when I got it. When I first got the pig, I made a Jacobs ladder. I just
hooked the outer LV terminals of the pig to the welding cables from the
Airco generator. I made the ladder from scrap 1/4 copper tubing. (I am also
an A/C Tech.) It worked O.K. Then I hooked up the pig as a Jacobs Ladder to
the pri. of the JCP welder as a ballast. Sucked. Then I got an element from
a furnace and used a resistive ballast. That worked fine, but got very hot.
I then used a furnace as the ballast so I could use the fan to cool the
element, and used the whole furnace, so I could vary the resistance by using
jumper wires to connect the various elements in series/parrallel and that
was cool. Then I hooked up the TC (the 4" coil) and learned how to ballast
using the furnace. I then used the welder because a lot of people on the
list recommended welders as ballast. I found that my welder worked best with
a bit of resistance added. I was using a static gap at the time, with a five
HP air compressor (two stage, industrial) to quench. After that I built my
first SRSG and found that resistance was not necessary any more. Then I
tried to match John Freau's efficiency and found that I was wasting a lot of
power. I got better results using the welder with the sec. open (higher
inductance, but much less control) than with the sec. shorted. The sec. has
two taps, high and low, and the best results (streamer length) were with the
sec. open. I then tried a golf cart batt. charger trans. as a ballast, but
it was not the ticket. Now I have a 15/60 Franceformer (new style, with all
the sec. GFI removed, burned up so sec.s are shorted internally) as a
ballast, and it beats the heck out of the welder. I can approach John's
efficiency with a sec. that has 800 turns of 26 AWG at 40 TPI and a 16nF pri
cap. No PFC, just VAR, and spark length is close. Not there yet, (1.7 X SQRT
power in) but the shorted sec's. do introduce a resistive (AKA lossy)
factor. With a 48nF cap I got a one time spark of 80", 4X the winding
length. (Was using the welder as ballast at the time) 3X is easy with 24nF
and the tests I run are with a MMC of 16nF (made from 26nF Panasonics from
Terry) which is not nearly as lossy as the Radar caps the other configs. are
from. I think that you also run a 4" or 4.25" coil similar to mine, and
would be very interested to see the results you get with this welder.  BTW,
my pig is also a 5KVA 14400V.

later

deano



> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Thursday, May 24, 2001 12:34 AM
> To: tesla-at-pupman-dot-com
> Subject: New Ballast
>
>
> Original poster: "Gregory Hunter by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>
>
> Dear List,
>
> After months of daydreaming about a better ballast (my
> present setup is two MOTs for a fixed 240V/20A) for my
> 5kva pole transformer, I hit upon a plan last week.  I
> took out an ad in the local "Shopper's Guide", a dinky
> little free classified paper, asking anyone with a
> broken 240V stick welder to please not throw it away,
> but sell it to me.  My grand plan was to rewind it and
> make myself a custom ballast.  The paper came out
> yesterday, and today I got two phone calls.  One of
> them was practically my neighbor.  I drove down to his
> house and beheld a neat little "Buzz Box" brand
> 240V/230A stick welder sitting in his driveway.  The
> gent told me he never could make a good weld with it,
> and he figured one of the "diodes" was burnt up.  For
> $25 bucks I took the welder home, where I quickly
> removed the sheetmetal jacket for a hasty appraisal.
> The stick welder has no diodes, of course, nor any
> other electronics.  The transformer windings appear to
> be in perfect condition.  The adjustment is the
> infinitely variable type where the shunts slide in &
> out of the core windows like a trombone.  Max primary
> current is 48 amps at 20% duty cycle.  The thing is
> dusty, and some of the internal copper connections are
> green with age.  Otherwise, it appears barely used.  I
> can't wait to wire this little jewel up to my pole
> xfmr.  I didn't walk away with a free substation like
> the geeks seem to be able to do, but I'm well pleased
> with my own modest little victory in the fight for
> low-budget coiling.  Try the classified ads thing--no
> telling what kind of stuff you might pull in--dead
> microwave ovens, old welders, old x-ray xfmrs?  Who
> knows?
>
> Regards,
>
> Greg
> http://hot-streamer-dot-com/greg
>
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