| 摘要 |
PURPOSE:To eliminate an irregular rotation and an abnormal noise by switching an applying voltage or current to different value when a rotating speed becomes a value within a range to resonate. CONSTITUTION:The frequency of a pulse signal generated from a pulse generator 1 is slowly varied to a high frequency corresponding to the set frequency from a low frequency corresponding to a starting speed. In the meantime, an exciting current controller 6 connected with the output of the generator 1 compares the frequency (f) of the pulse signal generated from the generator 1 with the set value determined corresponding to the intrinsic vibrating frequency fres of the rotating system (including a load 4) of a step motor 2, produces a control signal to a power source 4 when the f approaches the prescribed range of the fres to switch the exciting current to different value. Thus, irregular rotation occurred due to the resonance and the abnormal noise can be suppressed. |
