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:
Feb. 08, 2000
Filed:
May. 13, 1999
Applicant:
Inventor:
Leos Chalupa, Jemnice, CZ;
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ; H02P / ;
U.S. Cl.
CPC ...
318439 ; 318254 ; 318430 ;
Abstract
In a method for operating a brushless motor with commutated stator excitation and permanent rotor field, the stator is initially energized partly. Depending on the polarity of the back electromagnetic force (EMF) in the non-energized stator coil at a predetermined time point (t(n)+T.sub.OFF) and on the occurrence of a EMF zero-crossing event in a following time frame (T.sub.MONITOR), the next stator commutation (t'(n+1)) is scheduled. Thereby, three cases (i)(ii)(iii) are distinguished and detected events (.tau.(n-1)) in previous commutation cycles (n-1) are taken into account.