| 摘要 |
PURPOSE:To prevent the generation of sparks at the outlet and inlet sides of a brush by regulating the current of an interpose auxiliary winding so that a load shaft of an armature current is moved to the vcinity of the lower limit of a sparkless zone. CONSTITUTION:When a load is small or when a rotor is stopped, it is detected by an operation setter 21 to open an analog switch 22, thereby stopping an input of a signal to a gate signal generator 16. Thus, the generator 16 does not operated, and no current flows to an auxiliary winding 7. When a rotor rotates and a load is applied, the generator 16 and a current controller 17 control the current of the winding 7 along the pattern generated from a pattern signal generator 20 In this manner, the load shaft of the armature current is set to the vicinity of the lower limit of the sparkless zone. |
