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:
Jun. 06, 2000
Filed:
Feb. 16, 1999
Bernard Jean-Pierre Grehant, Nancy sur Cluses, FR;
Lionel Petit, Caluire, FR;
Bertrand Nogarede, Toulouse, FR;
Somfy, Cluses, FR;
Abstract
Supply circuit for a piezo-electric motor comprising a rotor driven, by friction, by a stator energized by at least two piezo-electric elements (P1, P2) supplied respectively with two alternating voltages (Vp, Va) of like amplitude and phase-shifted by approximately 90.degree. by means of a single source and of a means intended for generating the two phase-shifted voltages. This means consists of a capacitor (C), in series with one of the piezo-electric elements (P2), whose value is chosen so that for a given frequency of the voltage of the source (S), substantially the same voltages and a phase-shift of 90.degree. is obtained. The voltage of the source is advantageously controlled, in frequency, by a processing logic unit (PLU).