| 摘要 |
PROBLEM TO BE SOLVED: To improve the service life of a brush. SOLUTION: When the number of revolution of a motor which is detected with a sensor of the number of revolution and an armature current which is detected with a sensor of an armature current exceed a limiting map B, a chopper command in which the duty ratio is made lower than the value before the detection is outputted to a transistor for an armature. Thereby the armature current and the number of revolution of the motor are decreased, so that the state is prevented from going into a region A, where the service life of a brush is extremely shortened by generation of a spark.
|
