Armature Coefficient

Constant depending upon the number of turns of wire b in the armature of a dynamo-electric machine, upon the average area a of the turns, and upon a coefficient k, which represents the number of times the effect is increased by the soft iron core. If we represent the armature coefficient by A, we may write, A - kab, k is the "coefficient of magnetic permeability" of the core. The quantity A is sometimes called the "equivalent area," and is the area of a single turn of wire which would produce the same difference of potential as the armature in question, including its many turns IMG:content-0296.png:[graphic] and core.