lashing of Dynamo

—Flashing or sparking which is liable to take place at the brushes of a commutator. It may arise from bad adjustment or condition of the brushes, bad condition of commutator, overload of dynamo, loose connections, disconnections or short circuits in armature circuit, and similar causes. When sparking occurs at the brushes of a good dynamo, two kinds may generally be distinguished by the experienced eye, viz., those sparks due to bad adjustment of the brushes, generally of a bluish color, small when near the neutral points, and increasing in violence and brilliancy as the brushes recede from the correct positions upon the commutator; those due to a dirty and neglected state of the commutator and brushes, these being distinguished by a reddish color and a spluttering or hi ing. When due to this last-mentioned cause, it is impo ible to suppre the sparking until the commutator and brushes have been cleaned up. In the former case, the sparks will disappear as soon as the brushes have been rotated into the neutral points.