On Tue, 02 Aug 2005 18:28:32 GMT, TokaMundo
wrote:

On Tue, 02 Aug 2005 10:54:26 -0700, John Larkin
Gave us:

Before any difference could even be noted, the wired diameter would
have to be over 16 mm.

Not so. At 0.85 cm depth, current density is down to 1/e (ie, only
0.37 of) the surface density. That's pretty significant.

0.85 cm is pretty thick. 8.5 mm in fact. Double that to get 17mm.

Unless the wire is larger than 17mm at 60Hz, the entire wire will
carry current. VERY simple math.


Current begins to fall off monotonically from the very surface for any
wire size at any AC frequency. There's no hard "skin boundary", and
the 1/e density is just a handy if arbitrary measurement point.

I don't see why this needs arguing over. In a given situation, you
just calculate the effects and decide how they affect things.
Sometimes a 200% increase in resistance doesn't matter, and sometimes
a 1% increase does. But skin effect does often matter in real
situations at 60 Hz, and shouldn't be always/automatically discounted.

John