Date:         Sat, 19 Jun 2004 02:23:00 -0400
Reply-To:     "Daniel L. Katz" <katzd54@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "Daniel L. Katz" <katzd54@YAHOO.COM>
Subject:      Re: vanagon single electrode plugs

list:

i feel compelled to defend the attempt to analyze a 4 electrode plug as
four parallel resistances - because it is a brilliant generalization. but
sparks are a complicated transient phenomena, and it is also true that one
path will spark first, and later sparks may or may not form across the
other paths on the same combustion stroke. the real fly in the ointment is
that "R" is not a constant. in fact, R is a function of the current
itself, and drops from essentially infinity across an initially unionized
gap, to maybe 1,000 ohms or less at peak spark current. in other words,
the gap is an example of a nonohmic device, i.e., one that does not obey
ohm's law.

in the original post, the equations for parallel resistances and
electrical power dissipated in resitors are correct.

also, recall that the coil is not a power supply.

in any case, there is no mechanism for a single vs multi electrode plug to
damage a coil.

dan


On Thu, 17 Jun 2004 05:10:03 -0700, Chris S. <mrpolak@YAHOO.COM> wrote:

>--- developtrust <developtrust@COX.NET> wrote:
>> Does not make sense. Electricity will always take the least
>> path of
>> resistance. Right? William
>
>> > To me, if you provide four paths to ground then the
>> impedance of the plug
>> > becomes R/4 since said paths are in parallel. Substituting
>> into above
>> > formula you get Power=4*V^2/R or four times the power is
>> required from the
>> > coil.
>
>You are correct William, and the above formula is not.  The
>quad-tip spark fires only ONE spark at ONE time.
>
>
>
>=====
>Chris S.'85 Westy Camel -> http://www.knology.net/~vw/dadada.jpg'84 Westy
Hershey -> http://www.knology.net/~vwghost/hershey/'01 NB TDI ->
http://www.knology.net/~vw/Beetle.jpg