Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!bloom-beacon!think!eplunix!raoul
From: raoul@eplunix.UUCP (Otero)
Newsgroups: sci.electronics
Subject: Re: HIGH VOLTAGE STUN GUNS'S
Summary: Voltage vs. power vs. current vs. energy
Keywords: HIGH VOLTAGE, STUN GUNS
Message-ID: <752@eplunix.UUCP>
Date: 7 Jun 89 22:17:27 GMT
References: <426@aucis.UUCP> <19134@cos.com>
Organization: Eaton-Peabody Lab, Boston, MA
Lines: 35

In article <19134@cos.com>, ssr@cos.com (Dave Kucharczyk) writes:
> In article <426@aucis.UUCP> jchan@aucis.UUCP (Jimmy Chanaga) writes:
> >I have the schematics to build a stun gun that delivers 75,000 volts at 
> >25,000 watts from an input of 9.8 volts DC.

>   a few questions.  where do you get the tractor-trailer sized 9V
> battery for the thing ?  [various scheves described suitable for
> powering a small town]...

Aaargh. Look, a typical 9-volt battery can put out ~3000 joules per
recharge. At 75,000 volts, that will provide 1 second of power at
40 mA. That is more than enough to punch most humans through a wall
convulsing with every muscle, including their heart. If resistance
across human skin is roughly 10 kohm or more, that 75,000 volts will
produce 7.5 amps to dissipate whatever energy the device has stored.
Power output will be 1/2 million watts. Now obviously, the device
stores energy in some way to produce a 75,000 voltage, so the limit
comes from the device energy storage, not the battery. (The internal
resistance of the battery prevents draining power that fast directly: 
if you want, I'll send schematics and models, but you can take my word
on it for now). 

Don't believe me: Fine. Take a 9-volt battery. Connect the leads to an
inductor, say 10 uH for safety. The inductor will charge up with current
and energy, that current being limited by resistance of the battery and
parasitic resistance in the inductor. From a few feet away, with a 
*wooden* pole, disconnect the leads. Wear glasses, the arc will be small
but is sufficient to pop across the length of the leads and fry the
mess.

-- 
			Nico Garcia
			Engineer, CIRL 
			Mass. Eye and Ear Infirmary
			eplunix!cirl!raoul@eddie.mit.edu