Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!umn-d-ub!umn-cs!ns!logajan
From: logajan@ns.UUCP (John Logajan)
Newsgroups: sci.electronics
Subject: You're a capacitor. Was: Electrocution -- Is this possible?
Message-ID: <1208@ns.UUCP>
Date: 16 Mar 89 16:53:23 GMT
References: <7571@polya.Stanford.EDU> <7528@batcomputer.tn.cornell.edu> <633@sunset.MATH.UCLA.EDU>
Organization: Network Systems Corp. Mpls MN
Lines: 18

Harold Wong writes:
> I have a line tester consisting of a screwdriver (the probe) connected to a
> neon bulb connected to a metal cap on the end which I'm suppose to touch. 
> How does this work?

You are a capacitor.  Current (very tiny amount need to light neon bulb) flows
from the line through a resistor, thru the gas in the bulb, into you.  The
current then reverses and flows the other way.  It does this 60(50 euro) times
a second.  If it was DC you would quickly charge to line potential and the
current would drop to leakage amounts.  This might or might not be enough to
keep the bulb glowing -- I don't know.  Leakage can be through several
mechanisms.  Most significantly, water in clothing in contact with other
objects, and evaporated water to "broadcast" your charge into the surrounding
air.

-- 
- John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428  -
- ...rutgers!umn-cs!ns!logajan / logajan@ns.network.com / john@logajan.mn.org -