| 摘要 |
PURPOSE:To maintain safe operation of a motor by comparing the output level of a position detector so as to detect the phase interruption. CONSTITUTION:The output signals Hu, Hv, and Hw of three pieces of position detectors 1-1, 1-2, and 1-3 have differences of 120 deg. respectively, and seeing the conditions of other two phases at the position of the edge where the signal of Hu signal changes from H to L, other two phases are the phases reverse to each other such that if the Hv phase is H, Hw phase surely becomes L. So at the position where if one phase Hw has become phase interruption among them, the output of the phase interruption does not change, therefore it becomes the output at the same level as other one phase Hu, and the phase interruption can be detected by detecting this condition. Hereby, the open phase can be detected regardless of the rotational direction and the rotational speed, and the safe operation of a brushless motor can be maintained. |
