Path: utzoo!attcan!uunet!amdahl!ames!vsi1!wyse!mips!prls!gordon
From: gordon@prls.UUCP (Gordon Vickers)
Newsgroups: sci.electronics
Subject: Re: Electrocution -- Is this possible?
Message-ID: <19861@prls.UUCP>
Date: 10 Mar 89 19:36:00 GMT
References: <7571@polya.Stanford.EDU> <7528@batcomputer.tn.cornell.edu>
Reply-To: gordon@prls.UUCP (Gordon Vickers)
Organization: Philips Research Labs, Sunnyvale, California
Lines: 40

In article <7528@batcomputer.tn.cornell.edu> eacj@tcgould.tn.cornell.edu (Julian Vrieslander) writes:
>
->Usually headphone circuits run at low voltage, but there might have been a
->fault causing the signal or ground side of the cable to carry line voltage.
->The current that passes into your body when you get a shock depends on the
->resistance in the path.  This situation sounds like a worst case.  The victim
->was biting on the cable (pressure + moisture = low resistance between wire and
->body).  He was sitting on a metal commode (large contact area on metallic
->surface with a low impedance path to ground).  The current path from mouth
->to seat is largely water (low resistance) and goes by his heart.
->
->I'm not too surprised.
->-- 
->Julian Vrieslander 

      I agree with everything you say but a couple of things still disturb
   me.
      Normally, the audio is coupled from the output stage of the amplifier
   to the headphone jack with a transformer.  Normally when a transformer
   faults, it is an open on either the prymary or the secondary side. An
   electrocution would require that the transfromer shorte from primary
   to secondary. Not unheard of, but very rare I beleive.  All this assumes
   that the TV was an old one, probably having tubes.  Newer small TV don't
   use transformers, and drive the earphones directly from the amplifier
   final output transistors but the voltage supplied to these is most likely
   low voltage, lower than the minium of 32 Volts normally required for
   a lethal jolt. Still not impossible , I agree.  Since he bit the wire,
   he did provide a much lower resistances path than in typical accidents.
   
      What I don't understand, is why was he attempting this repair in the
   bathroom and why did he choose to work naked ?
         - possible but unlikely source of lethal voltage
         - unlikely place for a T.V.
         - unlikely place to repair a T.V.
         - unlikely form of dress for task

     I'm surprised anyway.
Feeling gabby today; third follow-up to this group today.
Gordon Vickers 408/991-5370 (Sunnyvale,Ca); {mips|pyramid|philabs}!prls!gordon
Every extinction, whether animal, mineral, or vegetable, hastens our own demise.