| 摘要 |
Apparatus may be inserted in the casing of a d.c. motor or a d.c. generator for measuring not only the magnetic fields prevailing in the machine but developing other useful information. The magnetic fields between the field poles and the armature, and also the armature/mmf fields aligned with the brushes may be measured. The measurements of the fields permits a complete plot of the fields in the machine and also permits a test to be performed to see if the brushes are at their optimum positions. If a brush is not at its optimum position, the brush may be shifted back and forth until the maximum mmf, due to the current through the armature is aligned midway between the leading and trailing ends of the brush area coverage on the commutator. |
