| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor speed controller for controlling the rotational speed of a motor accurately by obtaining a net speed error signal, in which where periodical fluctuation, e.g. duty error and phase error, is corrected and realizing a wide control band thereby increasing the servo gain. SOLUTION: A motor speed controller comprises an FG(frequency generator) sensor 2 producing N (N is an integer of 1 or above) pulse signals during single revolution of a motor 1, and a wave form shaper circuit 3. Motor speed is controlled, based on the output from the shaper circuit 3, i.e., period information (b) of an FG pulse signal (a). An FG fluctuation correcting circuit 5 corrects fluctuation of period between edges, using information (b) of period t(0) between the rising edge and the falling edge of the FG pulse signal (a) and the period t(1) between the falling edge and the rising edge thereof. |
