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. 20, 2012
Filed:
Oct. 31, 2007
Ari Lumbantobing, Issaquah, WA (US);
Kevin Miller, Bellevue, WA (US);
Meindert Norg, Canonsburg, PA (US);
Pieter Johannes Bax, Drachten, NL;
Ari Lumbantobing, Issaquah, WA (US);
Kevin Miller, Bellevue, WA (US);
Meindert Norg, Canonsburg, PA (US);
Pieter Johannes Bax, Drachten, NL;
Koninklijke Philipes Electronics N.V., Eindhoven, NL;
Abstract
The adapting system for a resonant drive appliance includes a circuit for measuring the back EMF induced in the stator coil of the motor following turn-off of the appliance. The frequency of the back EMF signal is determined from the zero crossings of the EMF signal. The determined frequency is then compared with a running average of previous frequency determinations, and the drive frequency of the appliance is adjusted if the difference between the compared frequencies is greater than a threshold value, e.g. 1 Hz.