| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately control the speed of an elevator by accurately detecting a current at all times by eliminating a detection error by the residual magnetic flux of a current detector. <P>SOLUTION: The current fed from an inverter device 104 to a motor 106 is detected by current detectors 105A, 105B. A control device 110 drivingly controls the inverter device 104 according to the current value detected by the current detectors 105A, 105B. Each time an elevator stops at a target floor, for example, the control device 110 returns the current detectors 105A, 105B to a reset state by flowing a current for demagnetization to these current detectors in a short time. Since the detection error by the residual magnetic flux is eliminated, the speed of the elevator can be accurately controlled by always accurately detecting the current. <P>COPYRIGHT: (C)2008,JPO&INPIT |
