Re: plating xmas balls

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

is the side getting "whacked by the electrons" the positive or negative
side?  Recall that current flows from positive to negative, but the
electrons actually flow from negative to positive (thank you Ben Franklin...
two ways to define it, and happened to pick the wrong one!)

But, in any case, the transfer of material from one side to the other of a
DC gap is a well known phenomenon... Same thing occurs on DC switches, or,
for example, ignition points in a standard Kettering ignition, when the
"condensor" (capacitor) is the wrong value.

If I were to make some random surmises, rather than going down the hall and
actually getting the book that talks about this, think of this.  Arcs are
characterized by having a distinct "cathode spot" (or spots, depending on
current) where as the anode is more diffuse.  The temperature distribution
on the electrodes is very different.  The voltage distribution along the arc
is also not even, so the heat dissipation will vary.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, December 12, 2003 6:56 AM
Subject: Re: plating xmas balls


 > Original poster: Ian Macky <ian.macky-at-oracle-dot-com>
 >
 >  > Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
 >  > I have never heard about this. Since it's the air that gets hot, and
 >  > the currents in the terminals are identical, why would one of the
 >  > terminals get hotter? DC sparks are assymmetrical in appearance, but
 >  > the current looks very uniform.
 >
 > i was taught at a national-level school so i can guarantee those
 > figures.  welders are a very practical lot, and much of welding data
 > was arrived at through empirical means with no model backing it up.
 >
 > all i know is, in a DC arc, the side getting whacked by the electrons
 > gets more heat.  could there be a kinetic component?  most of the heat
 > goes into the electrode and material being welded, not into the air.
 >
 > --ian
 >
 >