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:
Aug. 02, 1994
Filed:
Mar. 22, 1993
Michelangelo Manini, Bologna, IT;
FAAC S.p.A., Bologna, IT;
Abstract
A method for control of the speed of an asynchronous electric motor by powering the motor with a single-phase sine wave voltage for its running at rated speed, and supplying it with at least one first partialized voltage formed from the sine wave voltage for a half-period or half cycle thereof, for running the motor at speed reduced to a fraction of its rated speed. A device for applying the method including a first power supply applied to the motor with a sine wave voltage for running at rated speed and a second means power supply applied to the motor with at least one first partialized voltage formed from the sine wave voltage for a half-period of the sine wave every uneven number ns of half-periods thereof for running at a motor speed reduced to a fraction of rated speed. Control apparatus sends activation signals alternately to the first and second power supplies upon reception of control signals requiring running at rated speed or reduced speed.