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GM HEI coil...

Hi All,

	I have been busy with other things but today I did some more testing on my
little Tesla coil made out of a GM HEI coil.

	With ~1000 volts in it was putting out ~8 arcs for about an hour at 1BPS
with no problems.  At 1400 volts it was getting 12 inch arcs easily and
seemed happy for about 10 minutes.  At ~1600 volts it reached a new record
of 13 1/4 inches (~190kV) for two great arcs then the gap sound mellowed
out :-((  The secondary failed this time.  Probably either broke the wire
or failed the insulation.  To hard to dig into and find it, but it appears
that arcs around 1 foot long are reaching the limits of the GM design.  A
well made coil's primary seems to be able to stand up fine to the stress.

	There may be a new coil however.  Fords TFI-IV ignition system uses a very
similar coil with cosmetic changes.  Known as the "E-Core" coil.  It is a
little larger than the GM but a very similar design.  I don't know if it is
cheap or not but I'll give it a look as I go to buy yet another coil...

	I have decided that the 300 volt photo flash power supply just doesn't
have enogh juice for this coil.  The spark gap is very hard to control.
Advanced users could use a transistor or something but the simple gap at
300 volts is just too hard to work with.  1000 volts is a much better
region of input voltage.  It also creates arcs that are very impressive
compared to the typical output of an ignition coil.  The thing should be
fairly reliable at this level.  I am looking for a super easy 1000V low
current power supply.  Something that could be taken out of a cheap
product, like the disposable camera one, would be perfect.  Beginners may
not want to mess with too much electronics so something simple, easy to
get, and safe would be great.  If anyone has any ideas on this please
e-mail me directly. 

Thanks,

	Terry
	terrf-at-verinet-dot-com
	Still holding the GMHEICSLR at 13.25 inches. :-))

BTW - I never heard a shread on the two coil 3 foot sparks system.  Todays
testing would suggest that the coil would not stand that voltage...  I
think my GMHEICSLR is safe for the moment :-))