Equalizing currents in the armature of a D-C. machine

WHEN THE PARALLEL type winding was first used on the armatures of large d-c. machines, it was almost impossible to obtain sufficiently good magnetic balance of the main field circuits to permit satisfactory operation. In 1896 the idea was conceived of automatically balancing the flux in the main poles by connecting together those points on the armature which normally should be of the same potential. These equalizing connections have proved themselves capable of taking care of considerable unbalance in the same field; in fact their performance has been so satisfactory that little study has been given to the details of this action.