| 摘要 |
PROBLEM TO BE SOLVED: To provide a controller for motor, capable of attaining the desired rotational characteristics of a motor with a simple structure even in case of a load fluctuation. SOLUTION: For example, a sequence controller 23 controlling a single-phase induction motor 21 used for stirring fluid alumina drives the induction motor 21 by applying a pulse signal of the frequency corresponding to the target rotational speed of the induction motor 21 set at a group 25 of speed setting switches to a group 27 of electric power switches. The target rotational speed set at the group 25 of speed setting switches is prescribed as the magnitude of the rotational speed at a prescribed torque close to the maximum torque of the induction motor 21. As a result, the single-phase induction motor 21 rotates at a fixed torque and at the rotational speed meeting a change in viscosity the alumina 1 due to the stirring condition of alumina 1, regardless of the change in the viscosity. The rotation of the induction motor 21 is generated by the rotation of a stirring magnet accommodating alumina, thereby permitting alumina to be stirred. |
