Re: Strange shock

["D.Wightman" <dwightman-at-mmcable-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

hello chris!!! hope the variac is working well for you. about the shock you
recieved it was most likely static electricity. it is rather common for a
static charge to remain on the secondary coil form for quite some time.
especially on pvc.


-----Original Message-----
From: Tesla list <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Friday, July 07, 2000 7:33 PM
Subject: Strange shock


>Original poster: "Chris Brick" <cbrick-at-rebelbase-dot-com>
>
>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
>transformer.
>
>Thanks,
>
>Chris
>
>
>