Method for regulating duty ratio of periodic signal of variable frequency during regulation of speed and position of motor shaft of engine of machine tool, involves correcting successive half-waves, and alternately correcting duty ratio

摘要

The method involves correcting successive half-waves of a periodic signal (V-0) to a predetermined set point based on the ratio of half-wave durations. The duty ratio is alternately corrected based on the ratio of the half wave durations (t1, t3) of positive half waves (HW1, HW3) to the half wave durations (t2, t4) of negative half waves (HW2, HW4) and the ratio of the half wave durations of the negative half waves to the half wave durations of the positive half waves. An adjusting signal for correcting the duty ratio of the periodic signal is produced based on the two ratios.