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:
Jan. 11, 2011
Filed:
Feb. 28, 2008
Ulrich Kern, Witterschlick, DE;
Stefan Pöhler, Waldbüttelbrunn, DE;
Hans Otto Seinsch, Garbsen, DE;
Atlas Copco Energas GmbH, Cologne, DE;
Abstract
A method for turning a three-phase alternating current motor on again, after it has been separated from a supply voltage, if a residual field voltage induced by a rotor residual field is present, and to an electrical circuit for implementing the method. The time progressions of the residual field voltage and the supply voltage are recorded, and the phase difference between the voltages is calculated in advance from the time progressions. A time point tis determined, at which the phase difference goes below a predetermined maximum value Δφ. A switching command for applying voltage is triggered at a time interval that corresponds to a predetermined switching time delay τ, before the time point tis reached, so that the motor is connected to the supply voltage approximately at the time point t. The electrical circuit has a measurement value detection device, a microcontroller and a direct current setting device.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile