| 摘要 |
PURPOSE:To reduce a commutation noise generated in a motor by composing a voltage source as a drive circuit. CONSTITUTION:A control circuit 11 supplies a voltage Vs in response to a deviation between a frequency signal (f) and a reference frequency signal f0 from a tachometer generator 13 is supplied to the base of a transistor 14. The transistor 14 forms a voltage source together with a transistor 15. Thus, since a noise voltage generated by the commutation is shortcircuited by the low impedance of the voltage source, electromagnetic noise can be reduced. |
