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:
Nov. 10, 1998
Filed:
Nov. 12, 1996
Roland Luthier, Villars-sous-Yens, CH;
Fridolin Wiget, Neuchatel, CH;
Asulab S.A., Bienne, CH;
Abstract
The invention concerns a method for exciting and monitoring a piezoelectric motor (M1) in stepping mode, the motor having a resonance frequency (f.sub.R) and being supplied electrically at an excitation frequency (f.sub.E) during each operating step. The method is characterized in that it comprises a monitoring phase which extends at least over several successive steps of said motor and in which, for a present step of said motor, a determined excitation frequency value (f.sub.E +1) is used, the duration (t.sub.E +1) of the present step is measured, said duration (t.sub.E +1) is compared to the duration (t.sub.E) of the preceding step and, according to the result of this comparison, said excitation frequency value (f.sub.E +2) is corrected for the following step in a direction tending to reduce the duration of the step. A circuit is also described which enables the implementation of the method.