| 摘要 |
PURPOSE:To prevent an equipment from burning by providing the input of a temperature found with an inverter and a motor, to a current limiting circuit with the input of working command to the motor, converted to current command signal, and by limiting current to limit power. CONSTITUTION:Motor working command MC is converted to the current command signal CC of a motor 1 by a converter circuit 3, and the input to a current controlling circuit 4 is provided, The input of temperatures TI, TM detected by temperature sensors 6 and 5 arranged near an inverter 2 and the motor 1, to the current controlling circuit 4 is provided, and when the temperatures TI, TM are of a specified value or more, then the output of the limited current command signal CCl of the current command signal CC is directed to a power limiting circuit 7. The input of difference signal ID between current MCs and the current CCl to the inverter 2 from the power limiting circuit 7 is provided, and the inverter 2 is controlled so that the ID may come to zero. As a result, an equipment is certainly prevented from burning and is miniaturized, and the weight is lightened. |
