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Fwd: [DPRG] Shocking

Subject: Fwd: [DPRG] Shocking
From: Jeff Koenig koenig.jeff at gmail.com
Date: Mon May 15 12:31:46 CDT 2006

Sluggy sent me the following message, with permission to post to the
list.  Since he went into such nice detail, I just have to share it.

I personally wouldn't try these on any living subject, so I'll cover
myself by saying "caveat emptor", "don't try this at home", and finish
with Faber College's motto, "Knowledge is Good".

-Jeff

--- Sluggy! Wrote ---

When I was in the Radio/TV Electronics class in High Screwel, we, being
boys, built a lot of deleterious devices.

My two favorites were:

A cigar box containing a 6.3V filament transformer, 4 C cells and a two
homemade leaf switches, one with a weight on the end, balanced to induce
bouncing and the other in a hidden hole on the bottom. The battery,
switches and (intended) secondary of the transformer were in a circuit.
The lid of the box was situated so that keeping it closed kept the
switch open, but opening the lid let it bounce, pulsing current in the
transformer. The primary of the transformer was wired to aluminum foil
strips arranged on the bottom of the box such that it was very difficult
to hold the box without your hand contacting both leads, usually several
times. Open the box and you got about 5 or 6 jolting shocks to your
hand, assuming you held the box for that long. All of the components
were securely strapped down to a thin sheet of plywood, which was itself
glued and bolted to the cigar box. The builder had rebuilt the box
several times until it was robust enough to tolerate the usual dropping
of the box. When *he* held the box, he pushed a finger into the hidden
hole, opening the hidden switch and preventing himself from being
shocked.

The other device was much simpler, but much less compelling. Take a
100uF 200-500 volt electrolytic capacitor. If it had a bare metal case,
as most of the ones we played with did, wrap a single strand of
insulated solid conductor wire around it in a spiral pattern with a
minimum of about 1/2" between windings. If it was not  Glue the wire
with a single drop about every inch along it's length. Once the glue is
set, shave the insulation to expose the wire without shorting it to the
case. Hold it very carefully, touching only the case and not the wire,
charge the capacitor with the lab plate supply, then carefully toss it
to someone. The *first* time you do this, they will attempt to catch it,
receiving a nasty shock in the process. Assuming you survive their
retaliation, they will from then on dodge anything tossed at them by you
or perhaps anyone else.

I, of course, had to improve on the design, so I used a Cherry snap
switch that powered a hobby motor. The hobby motor shaft had a brush on
one end and a contact that rubbed the teeth of the gear so that opening
the cigar box ran the motor and gave a more 200 Hz cattle-prod level of
shock rather than the fence-charger pulse type of shock provided by the
bouncers. The contact required frequent adjustment because friction and
arching wore the brass teeth down pretty quick.

You can post these publicly to the list if ya like, but they'll be YOUR
fault then.. .hehehehe

Sluggy!


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