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Beginner's Tesla coil -First Light!



Hi All,
	
	10 inch arcs out of a GM HEI ignition coil!!

	I finally submerged the GM HEI coil in oil and let her go.  It easily
arced the 10" to a grounded salad bowl I was using to contain the mineral
oil incase something leaked.  It probably could have gone further.  This
was in single shot mode and the voltage should have been around 120kV.  The
arcs were strong and blew a hole through a bit of PVC.  I added more oil to
stop the "leak".  

	The high voltage supply was loosing it's mind when the coil fired, so I
used a bridge rectifier and hooked it to my variac-neon charging circuit
for my regular coil.  Thus I could fire it at a much higher rate than 1 BPS
(I was getting carried away at this point).  I knew much more power was
needed :-)).  The neon ran it right up there to ~10BPS.  Then the coil
blew! :-(  The primary looks like a short now.  I'll clean it in detergent
and do an autopsy tomorrow.  

	The caps (17 0.1uF 630V Polypropylenes) worked very well and once again
showed they could very easily take Tesla abuse.  The simple spark gap was
easily able to provide that function.  This coil only uses about 1/4 Joule
of energy so it should not be strained.  

	Of course, GM coils are not meant to put out 120kV or have 600 volt pulses
applied to their 12 volt primaries.  This one was on a car engine for 16
years so it may have been weak! :-)  At least the computer models and all
were proven out.  I will get a new one and try again at a bit lower input
power.  I got a little carried away when I saw those nice arcs.  I just
kept pumping more and more power into it!  I probably would have given it
the full 1kW! :-))

	If I can get this thing to hold together, it should make a very nice,
easy, and cheap beginner's coil.  With a new coil, I should be able to
stress it out more carefully and find were it blows up and back off from
there.  Today's tests suggest that it will still be a nice performer even
at less than destructive output levels.  

The science goes on....

	Terry