| 摘要 |
<p>A current, which is supplied from an inverter device to a motor, is detected by a current sensor. Based on the value of the current that is detected by the current sensor, a control device controls driving of the inverter device. At this time, the control device supplies a current for demagnetization to the current sensor in a short time period, for example, each time an elevator is stopped at a target floor, thus restoring the current sensor to a reset state. Thereby, a detection error due to a residual magnetic flux can be eliminated, and high-accuracy speed control can always be executed by exact current detection.</p> |
