| 摘要 |
<P>PROBLEM TO BE SOLVED: To smoothly control the speed of a motor, where time constant is relatively small such as in an ultrasonic motor having a relatively rough speed control profile and a simple constitution. <P>SOLUTION: A number of dividing-frequency calculating part 1 changes the number A of diving frequency with a comparatively rough speed control profile, and sets it in a number of dividing-frequency setting register 2. A comparator 3 outputs a positive count signal, when the number A of diving frequency set by the number of dividing-frequency calculating part 1 is larger than the present number B of dividing frequency, counted by the number of diving-frequency counter 4 (the number of frequency A > the number B of dividing frequency), and outputs a negative count signal, when the number of frequency A < the number B of dividing frequency. The number of dividing-frequency counter counts the present number B of diving frequency of a frequency divider 5, by counting up the enabling clocks with intervals t shorter than the the speed control profile of the number of dividing-frequency operation part, when a positive count signal is applied from the comparator, and counts them down, when a negative count signal is applied. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
