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:
Oct. 13, 1998
Filed:
Jun. 08, 1995
John Julian Williams, Auckland, NZ;
Christian John Gianni, Auckland, NZ;
Fisher & Paykel Limited, Auckland, NZ;
Abstract
A method and apparatus for controlling the speed of a multi-phase, brushless DC electrically commutated motor (ECM). Voltage is commutated to the windings of the ECM based on rotor position information derived from back EMF or Hall effect sensors. The application of the commutating voltages is arranged such that the voltage applied to the windings always leads the back EMF generated in the windings by a selected constant lead angle. The speed of the motor is then controlled by pulse width modulating (PWM) the voltage applied to the windings of the ECM.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile