| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rotational speed controller and a rotational speed controlling method of a motor capable of controlling the rotational speed of the motor to stay stably within a dead zone. <P>SOLUTION: When a measurement judging section 12 makes a decision that the measurement of rotational speed of the motor 2 from a rotational speed sensor 21 falls within a specified deviation range set for a target level, a duty ratio averaging section 13 starts counting of a timer. Furthermore, the measurement judging section 12 compares the measurement with the target level and a duty ratio calculating section 11 alters the duty ratio of a pulse width modulated waveform signal such that the measurement coincides with the target level. On the other hand, the duty ratio averaging section 13 determines the averaged value of duty ratio of the pulse width modulated waveform signal corresponding to the maximal and minimal values of measurements within a specified time when the specified time has elapsed. So long as the measurements fall within the specified deviation range, a control signal output section 14 outputs the pulse width modulated waveform signal of average value continuously. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
