| 摘要 |
PURPOSE:To enable accurately controlling the output displacement of a piezoelectric actuator by detecting the electrostatic capacity of the piezoelectric actuator at any time and by applying a desired potential based on the detected electrostatic capacity. CONSTITUTION:An apparatus is equipped with a drive circuit 2, a controller 3 for controlling the charge time or discharge time of the drive circuit 2 and a potential detection circuit 4 for detecting the potential of a piezoelectric actuator 25. The piezoelectric actuator 25 is charged with a constant current or discharged and the increase or decrease of the potential of the piezoelectric actuator 25 is detected so that the accurate electrostatic capacity of the piezoelectric actuator 25 is detected from the charged electric load quantity or discharged electric load quantity and from the increase or decrease of the potential of the piezoelectric actuator 25 and the potential of the piezoelectric actuator 25 is increased or decreased by the charge or discharge to a target potential corresponding to a desired output displacement on the basis of the detected electrostatic capacity. In this manner, it is possible to accurately control the output displacement of the piezoelectric actuator 25. |
