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From: amichiel@rodan.acs.syr.edu (Michielsen)
Newsgroups: sci.electronics
Subject: Re: Electric Fences (why does person on end get the shock?)
Keywords: electric shock
Message-ID: <1628@rodan.acs.syr.edu>
Date: 28 Dec 89 14:22:31 GMT
References: <3858@orion.cf.uci.edu>
Reply-To: amichiel@rodan.acs.syr.edu (Michielsen)
Distribution: na
Organization: Syracuse University, Syracuse, NY
Lines: 31

In article <3858@orion.cf.uci.edu> jroersma@orion.oac.uci.edu (John Roersma) writes:
>... regarding shocks from electric fences.
>... some kids would grab another person (or persons)
>and touch the fence, and that the person at the end of this human chain
>would get the (worst) shock (!).
>
>Why does the person on the end of the chain
>
>Who's correct here?  Have I made an oversight, or is there some other
>physical phenomenon involved?
>

My guess is two sided.  First, the middle person has 2 current paths. 1 to
Gnd, 1 to the next person.  The resistance to gnd is much > than that to the
next person, and most of the current goes to the next person. The neural paths
from hand to foot go through the spine which is integral in it's connection to
the brain & hence pain.  The pathway from hand to hand while does cross the
spine, it does not run 'with' the spine, and there are enough muscle cross
connects between the 2 hands that ths brain receives less pain info.
Secondly, the 'grabber' is prepared for the shock & pain. While the 2nd person
the 'shockeee' is surprised.  Pain prepared for is < the surprise pain.

Lastly - This reported experience is true.  I've done it myself.  I have never
seen a fence that will hurt a person. (they are illegal)  The shock will make
the inexperienced think they are about to die at any moment, but they can't.
You can feel free to play with it grabbing it & swinging you hand making
'surprise' contacts.  My experience is that no matter how familiar or 
experienced with it you are, the 'surprise' shocks hurt more than the 
intentional ones. )8-}}

al