| 摘要 |
PROBLEM TO BE SOLVED: To desirably control an oscillatory wave motor by properly controlling the phase of the motor even when the phase difference for controlling phase difference is inverted after the motor is started by waveform distortion, etc., by driving the motor in the speed increasing direction even when the phase different value falls in such a phase difference region that is not able to occur during normal operation at the time of starting the motor. SOLUTION: The count values corresponding to preset phase difference θ1, θ2, and θ3 are inputted to the other inputs of three comparator and, in the first, second, and third comparators, the phase differences between the phase differences between A and S-phases are respectively compared with the phase differences θ1, θ2, and θ3. When the phase difference between the A- and S-phases is inverted, the occurrence of such control that the driving speed of an oscillatory motor is decreased though the motor is just started by ignoring the phase status when a PLE3 is in an 'H' state, and so on, by judging that it is impossible that the PLE3 becomes the 'H' state under normal control, because it exceeds a resonance point. |
