Characteristic size of eddy currents in silver & copper

[fieldwrangler]

Folks -

So it seems, I may have attracted the interest of some Smart Guys in the worlds of metallurgy/materials science. They asked me about the general spec described in the title and I realized that I don't really know from this.

And so, once again, I put my question out to you Smart Guys.

Bob Palmieri

[Mike Sulzer]

The pattern of current flow is determined by the geometry of the metal and the changing magnetic fields.

For example, if you put a metal cover over a humbucker, you expect the largest currents in the sides looping all the way around because this path conducts, and it encloses the most magnetic flux. There also are currents in the top; it conducts, and from considerations of symmetry you expect roughly rectangular current loops with higher values of current towards the edges of the top (since the further out you go from the center, the more flux is enclosed).

Folks -

So it seems, I may have attracted the interest of some Smart Guys in the worlds of metallurgy/materials science. They asked me about the general spec described in the title and I realized that I don't really know from this.

And so, once again, I put my question out to you Smart Guys.

Bob Palmieri

[Joe Gwinn]

So it seems, I may have attracted the interest of some Smart Guys in the worlds of metallurgy/materials science. They asked me about the general spec described in the title and I realized that I don't really know from this.

While eddy currents don't have sharp edges, an easy way to think of it is that they resemble a blurred image of the coil current in the nearby metal, travelling in the opposite direction as the current in the coil.

Depth of Penetration & Current Density