| 摘要 |
<P>PROBLEM TO BE SOLVED: To certainly perform synchronous operation in starting a DC motor, and to detect stepping-out in a short time after its starting if it occurs. <P>SOLUTION: The DC motor 10 includes a rotor 2, three sets of three-phase stator winding 1u, 1v, 1w, and a stator pole. A position detecting circuit 4 determines a rotational position of the rotor 2 by monitoring the terminal voltage of sets of the stator winding 1u, 1v, 1w. An inverter circuit 3 and a control circuit 5 control energization to the sets of stator winding 1u, 1v, 1w of the DC motor 10 based on the position of the rotor 2 determined in the position detecting circuit 4. The control circuit 5 performs synchronous operation until the frequency of commutation of the sets of stator winding 1u, 1v, 1w reaches a specified frequency. A difference between currents passing through the sets of stator winding 1u, 1v, 1w in both of a specified point after the commutation of the sets of the stator winding 1u, 1v, 1w and a specified point before the next commutation is determined during the synchronous operation, and if the difference of the passing current is not more than a threshold value, it is determined as stepping-out condition. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
