| 摘要 |
PURPOSE:To substantially make uniform the difference of lifting power generated by the disparity in the frequency of use by a method wherein, when the deviation between the minimum current among the currents flowing in each electromagnet and the current flowing in each electromagnet exceeds the preset reference value, a structure wherein a resistor is series-inserted into the electromagnets is constituted. CONSTITUTION:The titled device consists of resistors 14a, 14b and 14c series- arranged on a plurality of electromagnets 4a, 4b and 4c, detecting devices 3a, 3b and 3c to be used to detect the current running on a plurality of electromagnets, a discriminating device 5 with which the minimum current among the detected currents is discriminated, a calculating device 6 to be used to calculate the deviation between the current flowing in a plurality of electromagnets and the minimum current, and a comparison device 7 with which the preset reference value and the above-mentioned deviation are compared with each other. When said deviation exceeds the reference value, a resistor is connected to the electromagnets based on the signal sent from each comparison device. As a result, the unevenness of the current running on each electromagnet can be brought within the tolerance limits. |
