| 摘要 |
PURPOSE:To contrive load reduction driving to be performed with maximum output in the whole rotational frequency area, by controlling rotational frequency so that the product of the rotational frequency by winding current cannot exceed a limit value. CONSTITUTION:By a rotational speed detection circuit 1, the rotational speed of a motor 7 is detected, and by a winding current detection circuit 5, winding current is detected, and the output of the respective detected once is directed to a multiplication circuit 2. By the multiplication circuit 2, the product of the rotational speed by the winding current is computed and axial torque is found. By an overload discrimination circuit 3, the shaft output of the motor and a limit value are compared with each other to be discriminated, and rotational speed command and actual rotational speed are compared with each other to be discriminated, and the output of the actual command of the rotational frequency of the motor is generated. By a drive circuit 4 of the motor, based on the command, the motor 7 is driven. As a result, with maximum output which can drive, continuous driving with little hunting can be performed, and the driving device of the motor can be miniaturized, and the capacity can be reduced, and a driving area can be widened. |
