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From: young@helix.nih.gov (Jeff Young)
Newsgroups: sci.electronics,alt.sex
Subject: Re: HELP!
Message-ID: <880@nih-csl.nih.gov>
Date: 30 Jan 91 16:28:16 GMT
References: <1991Jan19.052458.7449@wam.umd.edu> <1991Jan24.041804.13890@wam.umd.edu> <1991Jan26.041208.25354@athena.cs.uga.edu> <1991Jan28.055428.11686@wam.umd.edu>
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Reply-To: young@helix.nih.gov (Jeff Young)
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In article <1991Jan28.055428.11686@wam.umd.edu>, mauser@wam.umd.edu (Rich Chandler) writes:
|> In article <1991Jan26.041208.25354@athena.cs.uga.edu> mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:
|> >"It's not voltage that's dangerous, it's current"
|> >
|> >But voltage is the force that causes current!
|> 
|> Right, but it depends on how much energy is behind it.  (watts, joules, I 
|> forget my units.)  You can take a AAA battery, rig it to a coil that jumps
|> the voltage up to 40,000 and give someone quite a shock, but a perfectly
|> harmless one (My boss has a gag lighter that does just that).  You could also
|> hook someone up to the primary coil of you car ignition, also at 40,000 volts
|> and give them quite a serious shock.  Or you could drop a high tension line 
|> on them (yet again, 40,000 volts) and really fry them.
|> Through the right part of the body, between .1 and .2 amps can cause heart 
|> failure, and over .2 can kill.  (This from a chart in the lab in high school.
|> It suprised me too.  But think, nerve impulses are in microvolts...)

The chart should have gone a lot lower than that,  I seem to remember a few 
biomed courses which cited 10 microamps as enough current to send someones heart
into (check me if I'm wrong) fibrulation.  That was current originating in the 
body (ie. a catheter).  10 milliamps from the outside.  That's why everything
in a hospital room is equipped to deal with small leakage currents - ground fault
interrupters.  I haven't looked at that stuff in a while but I'm pretty sure
about the 10 uamps.

|> 
|> Also remember that there is more involved than just ohm's law.  Particularly 
|> with a battery involved.  The effective voltage of a battery drops the more
|> current you draw from it.  Your average 1.5 volt battery puts out 1.2 when you
|> use it, and even less under a high drain.


-- 

	jy 
	young@alw.nih.gov