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Strange shock

Hello coilers-

I had a strange experience on the 4th.  We ran our coil in Santa Cruz, CA 
as fireworks since they are illegal there.  We had a nice crowd and cars 
stopping for about an hour.  The coil ran great, at one point for almost 20 
minutes straight with no detectable heat in the MMC and no spark length 
degradation.  Good quality show with consistent 36" streamers to air from 
our little 15/30 NST.  Anyhow, after the show was over I proceeded to 
dismantle the coil as I have done a hundred times.  I removed the secondary 
after disconnecting all the wiring and capacitors.  I received a small 
shock from the secondary while holding it in my hands, away from everything 
and totally disconnected.  One of my engineer friends didn't believe me so 
he picked it up and got the same shock.  It is built on a 4". thin wall PVC 
drain pipe, sealed, and has 1/4x20 bolts epoxyed in each end.  The larger 
of the two shocks I got was from the bottom bolt.  The bottom of the 
winding is connected to the bottom bolt for grounding.  The top bolt is 
used to connect the toroid and doesn't have a connection to the 
windings.  Any thoughts on why there would be some charge built up in the 
secondary?  Either way, it didn't hurt and I didn't die, but I sure would 
like to know what it was all about.  I am not too familiar with Leyden 
Jars, but Steve the engineer had some ideas about the possible cause.

Also, those of you that are interested in rewinding a large transformer for 
Tesla use may find it worthwhile to become friends with a local commercial 
electrician.  I was just offered a 150KVA 240/2400 transformer for 
$150.00.  It seems once they punch the wiring holes, they can't return them 
to the distributor and can only sell them back at around $1 per KVA.  I am 
going to collect a few for the cores and build myself a nice sized