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. 12, 1999
Filed:
Apr. 10, 1997
Jean-Marie Bourgeois, Divonne Les Bains, FR;
Jean-Marie Charreton, Bouc Bel Air, FR;
Pierre Guillemin, Marseilles, FR;
Bruno Maurice, Eguilles, FR;
SGS-Thomson Microelectronics S.A., Saint Genis, FR;
Abstract
The invention provides a method for controlling a brushless motor, with windings connected in star (`wye`) formation, including the steps of periodically applying a supply voltage between first and second windings, detecting the presence of a current in a third winding, and an instant of cessation of that current, monitoring the value of a back emf induced in the third winding and detecting a zero crossing point of the back emf, timing a predetermined delay from the zero crossing point, and after the end of the delay, applying the supply voltage to other windings. The invention also provides a method for use with motors having windings connected in delta formation.