Large all resistive ballast

Guys - I'd like to tell you about a rather large resistive ballast I just 
constructed.  Until I get the coil components organized - I'm just running a 
pig powered Jacob's Ladder off of it...

Tonight I ran a pig-powered Jacob's Ladder.  This one was a bit
unusual since I used a 14000 pig, but fed it 240 across the 120 lugs,
for 28800 produced volts.  Those pigs seem to thrive on that sort of abuse! 
:)  Didn't even seem to saturate either.

Some pig stuff on my site is at:
(No JL shots yet)

The ballast was completely resistive, consisting of a bank of switches
and 16 1000w stove elements.

A very large (but free!) 3 phase contactor was used to interrupt the
power. The switches were the 50 cent type you get at the home
improvement store for wall plates, etc.  They are technically not
rated for 240 volt use, but they seemed to tolerate it w/o problem.

(It took about 4 hrs to construct this killer ballast - had to
build a steel frame for the heaters, drill a boatload of holes, build
a wooden box for the switches, find wiring lugs and busses for all the
leads, cut/strip/crimp connectors onto the heaters, etc...  Lots of work)

I used a large 24 inch window box fan to cool the stove elements.

I started at about 1KW.  Nice noisy arc which wouldn't climb.  At 2kw
the arc became much quieter.  At 3kw it started climbing nicely.

All this eventually ended up with all 16 heaters in parallel.  It was
drawing over 70 amps at 240 volts.  Now THATS a Ladder!  Yes they were
all red hot.  Current consumption was very smooth w/o excessive surges
or swings.

The arc was so hot that when the breeze would hold the arc still, the
wires would turn red hot at that point and sag, which would ruin the

The rods would start swaying.  Eventually the tops of the rods would
touch, which would draw an arc well over 18 inches long/  I need to
get the camcorder out to tape this action and freeze frame it!

I was initially using coathanger wire for the ladders, but they were
really getting soft by the heating, so I switched to type 308
stainless 1/8th inch rods.  Much better but still subject to sagging
should the arc dwell at the base too long.

I also tried painting the rods with water/salt.  Once dry - the arc would 
flame brilliant orange as it passed that part of the rod.  A neat trick!

Anyway - I should be set for ballast for any/all future tesla coil
work! :)

Pics pending.  I used 240 volt 1000W heaters from MECI, $1.75/each.
Cheap. I used neutral bus bonding strips (a row of screw wire
terminals) typically found in home breaker boxes.


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