| 摘要 |
PROBLEM TO BE SOLVED: To detect a rotational direction of a motor by a simple configuration while suppressing erroneous determination due to influence of noise.SOLUTION: In a rotational direction detection device (4), a detection unit (41) detects whether or not inter-line induced voltages (Yun, Vvn) coincide with each other. A filter unit (42) passes only a component belonging to a predetermined frequency band at least in one of the inter-line induced voltages (Vun, Vvn) in the vicinity of mutual coincidence of the inter-line induced voltages (Vun, Vvn). A determination unit (44) determines a rotational direction of a motor (2) on the basis of a filter value outputted from the filter unit (42).SELECTED DRAWING: Figure 1 |
