On Wed, 09 Mar 2011 15:13:15 -0600, Jon Elson
wrote:


There used to be large motors used for phase angle correction in large
factories, etc. They had a wound field, and the excitation was
controlled by a phase angle meter, to correct the power factor drawn
from the utility grid. They got a big break on their electric bill for
using such a device. Often called a "rotary condenser".

Those are over-excited synchronous motors.