On Fri, 03 Sep 2010 22:06:50 -0400, Wes
wrote:

Don Foreman wrote:


For given input power, efficiency is determined by losses: friction,
windage, current*resistance, hysteresis and eddy current.


So if someone needed a very efficent motor, what would they get using silver for the
windings? A couple percent?

Wes

About that. Resistivity of copper is 1.67, silver is 1.59.

Increasing magnetic flux density increases efficiency. This can be
done with better magnetic materials, tighter tolerances resulting in
shorter air gaps, rare earth magnets in PM motors, etc.

The usual tradeoff is efficiency vs cost. Size, weight and cost can be
traded for efficiency.