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:
Mar. 11, 2008
Filed:
Oct. 05, 2005
Stefan Jonsson, Stockholm, SE;
Jonas Beskow, Stockholm, SE;
Stefan Jonsson, Stockholm, SE;
Jonas Beskow, Stockholm, SE;
Aktiebolaget Electrolux, Stockholm, SE;
Abstract
The invention relates to a method for power control of an electric motor, in particular a motor for driving the suction fan of a vacuum cleaner connected to an AC mains power supply. The power control is effected by varying the phase angle of the electric alternating quantity supplied to the motor by the use of semiconductor switches. AC power supplied to the motor is switched by using different delay times for the switching in each half-period of a full AC period to suppress odd harmonics, particularly the third harmonic of the mains power line frequency. Half-periods of a full period are mirrored in the next consecutive full period in order to suppress even harmonics, particularly the second harmonic of the mains power line frequency. A set of delay times tand tare defined and selected to be used in further avoiding critical delay time areas for harmonics and minimize the generation of vibrations.