| 摘要 |
PURPOSE:To provide an ultrasonic motor diving circuit which can follow optimum frequency, covering a wide load range without arranging a special monitor electrode. CONSTITUTION:An ultrasonic motor driving circuit, which drives an ultrasonic motor 5 where a piezoelectric element is arranged by applying AC signals VA and VB being generated by switching transformers T1 and T2, using a DC power source 10, is equipped with a comparator 3, which detects the phase difference between the switching signal applied to the switching element to switch the transistors T1 and T2 and the AC signal, and a frequency control means, which controls the frequency of the AC signal, based on the output of this phase comparator 3. |
