OT OT OT OT OT OT OT OT OT OT OT RE: OT

[Magnus Danielson]

From: "Batz Goodfortune" <batzman at all-electric.com>
Subject: OT OT OT OT OT OT OT OT OT OT OT RE: OT
Date: Sun, 19 Dec 1999 12:39:05 +1000

> Y-ellow Y'all.
> 	I'm vieing for the Most off topic post to the list award in the "Still
> involves electrons flowing through a wire" category.

It has been covered before, among other things at SAS (which I assume that you
do not read due to the habbit of writing in Swedish on that list).

> I need to build a Stun Gun or cattle prod of some sort. The downside of
> skating is that you often get attacked by dogs and there is no defence
> against them. A few seasons ago I got pulled down by a rotweiler which took
> a chunk out of my calf. I can't import a stun gun because it is illegal to
> do so. But it's not illegal to make them. If only I knew how.
> 
> If anyone knows how to make a small one or knows of a web site with
> details, I'd be most interested if  you could email me. Privately perhaps.
> And I'm open to any other suggestions. However I can't think of anything
> else I could carry which wouldn't become a hazard for myself.
> 
> Thanks in advance.

Well, the key in stunning someone or somebody is to figure out how much
current you want trought the target object and how to get it there.
Another things is also how much damage you want to cause. You don't need
very much current going the wrong way in order to have someones heart go
still, less to make it jump. We are talking less than a miliamp here. OK.
Where's the catch with that? Actually getting it there.
The stun guns use the fact that you put them close to the object and then
use high voltage to jump the last part!

Ah, so we need a small current but high voltage, I can do that!

There are a bunch of diffrent ways to go about doing it, the most common ones
all use switching in some way. A classic method is to use some AC source and
form a voltage multiplier ladder with diodes and capacitors. You can build
such a ladder by forming the ladder legs by capacitors in series and then use
a diode to move from one level of one leg to the next level of the other leg.
You can reach pretty high voltages this way.

This method was used for creating the static field of the Quad 63 Electrostatic
speakers just to mention one nice on topic related use of the technique. It is
also used to supply HeNe tubes with the voltage (2-3kV and about 1 mA) that
they need to start lasering. Each creating stunning effects of their own ;)

Was this enougth for you to heat up the soldering iron and reach for some
left over caps and diodes?

Oh, beware, high voltage means the requirement for long creeping distances!!!

Hmmm... if you have that much trouble with dogs in Australia I migth consider
having some usefull protection when I go there... a few more months to
consider something...

Cheers,
Magnus (who keeps dogs away by carrying large obscure boxes around - it works!)