H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
H02K—DYNAMO-ELECTRIC MACHINES
H02K13/00—Structural associations of current collectors with motors or generators, e.g. brush mounting plates or connections to windings; Disposition of current collectors in motors or generators; Arrangements for improving commutation
H02K13/14—Circuit arrangements for improvement of commutation, e.g. by use of unidirectionally conductive elements