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Project update



cc: tesla-at-grendel.objinc-dot-com

Richard,

I thought I'd let you know what's been happening.  I built a spark gap
similar to the one I saw in your video.  With five 1.5" copper pipe sections
set up with my shop vac to draw air down between them.  I held them in place
clamped from the ends with several layers of .0625 polyethylene.  It did not
work very well.  A couple of the gaps worked correctly but two of them arced
at the ends only and burned a carbon trail in the poly.  Then I built a
single gap and tried using my shop vac in reverse to provide an air stream to
quench the gap.  This worked sort of.  Loud, but the coil did not perform as
well as it has been with the cylindrical gap.  In all of these tests, I am
still not able to get the primary to the pole pig above 125 volts.  I am
going on the assumption that this is still due to inadequate quenching of the
gaps and I am essentially shorting the HV outputs of the pig.  I now have
some resistive load in series with the welder - about 8000 watts of heaters
and oven elements.  The primary current is limited to about 15 amps at this
time.  The secondary should be about 7500volts.  This should put the
secondary current at about 200 to 250 ma.  I am surprised that my existing
gaps can't quench this.  It is only about 1900 watts and I was running at
about 1400 watts with my neons.

My next project is a rotaty gap.  Thanks for the input on this.  Right now I
am planning to use either lexan or aluminum for the disc.  If I use lexan, I
will use stainless steel acorn nuts for contacts as Mark suggested.  If I go
with aluminum I will use 1/8" tungsten held in place with set screws.  I am
planning to mount the disc on a separate shaft and belt drive it.  I will
start with the small sewing machine motor.  I can always go to a larger motor
later if need be.

BTW, I sure have seen some "interesting" posts on this list lately.  Must be
a full moon somewhere.

Ed Sonderman