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From: jmasters@pcocd2.intel.com (Justin Masters ~)
Newsgroups: sci.electronics
Subject: Re: Electric Fences (why does person on end get the shock?)
Keywords: electric shock
Message-ID: <1411@mipos3.intel.com>
Date: 28 Dec 89 02:11:47 GMT
References: <3858@orion.cf.uci.edu>
Sender: news@mipos3.intel.com
Reply-To: jmasters@fmdgr1.intel.com (Justin Masters ~)
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Organization: Intel FMD, Folsom, CA
Lines: 45

In article <3858@orion.cf.uci.edu> jroersma@orion.oac.uci.edu (John Roersma) writes:
+
+
+Please help settle an argument regarding shocks from electric fences.
+My parents both grew on farms with electric fences which would give
+a strong shock when touched.  They have told me that they had
+experiences where 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 (the person farthest
+from the fence) get the shock, assuming each person has roughly
+the same arm-to-arm and arm-to-ground resistance.  Modeling this
+as a resistive network shows that the person in contact with
+the fence will experience the largest arm-to-ground voltage drop
+(hence the largest current and largest shock).
+
+I have tried to state my case to my parents, although they have
+had the opportunity to experience the shock at both ends of the
+"chain", and will swear that the shock _is_ worse at the far end!

I'm hoping I'm right here...

From what I understand, the resistance between two people is much smaller than
the resistance through a body, your shoes, etc, to the ground.  What this does
is use the arm to arm linkage as a short, passing the current down to the last
guy who gets shocked.  I would assume that if the last guy is on a wooden
platform without any way to conduct to ground, then the person before him
would get a shock.  If I'm wrong, let me know.

+Who's correct here?  Have I made an oversight, or is there some other
+physical phenomenon involved?
+
+
++---------------------------------------------------------------------+
+John Roersma                                 jroersma@orion.oac.uci.edu
+Dept.of Electrical & Computer Enginering        jroersma@ucivmsa.bitnet
+University of California, Irvine    >> this space available for rent <<
++---------------------------------------------------------------------+


-----------------------------------------------------------------------------
Fireman to homeowner:    At one point we  |     Justin Masters
 decided to fight fire with fire...       |
 basically your house burned even faster. | jmasters@fmdgr1.intel.com