The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 25, 2016
Filed:
Sep. 28, 2011
Wladimir Wischnewskiy, Waldbronn, DE;
Alexej Wischnewskij, Wörth, DE;
Wladimir Wischnewskiy, Waldbronn, DE;
Alexej Wischnewskij, Wörth, DE;
Physik Instrumente (PI) GmbH & Co. KG, Karlsruhe, DE;
Abstract
A method for electrically exciting a piezoelectric actuator of an ultrasonic motor is described. The ultrasonic motor has at least one acoustic standing wave generator, including an exciter electrode and a general electrode, wherein a capacitance Cis developed between the exciter electrode and the general electrode. The method includes: applying a rectangular exciter voltage Uto the exciter electrode and the general electrode of the acoustic standing wave generator; providing a voltage Uwith the aid of a feedback element; separating a voltage ufrom a voltage uwith the aid of a pulse filter; and changing the frequency of the rectangular exciter voltage in such a way that the phase shift between the piezoelectric current Iand the rectangular exciter voltage Uis substantially zero. A device for electrically exciting a piezoelectric actuator of an ultrasonic motor is also described.