| 摘要 |
PROBLEM TO BE SOLVED: To improve the sensitivities of the abnormality sensings of hysteresis motors, by absorbing the variations of the current values of the current vectors corresponding to respective driving currents fed to the respective hysteresis motors, and by making small by the absorbed portion a threshold used for the abnormality sensings. SOLUTION: In this monitor, the current-value components of the current vectors outputted from respective current transformers 2 are converted by respective conversion circuits 4 to normalize the current vectors of respective hysteresis motors. Then, the current values of the respective current vectors are made to coincide with the current value of their average current-vector. When a larger difference than a preset threshold is generated between one of these respective current values and the average current value, the hysteresis motor corresponding to the current vector having the larger difference than the preset threshold is determined that it has been brought into an abnormal state. |
