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. 27, 2007
Filed:
Feb. 18, 2005
Jacob L. Lassen, Saupstad, NO;
Jacob L. Lassen, Saupstad, NO;
Atmel Corporation, San Jose, CA (US);
Abstract
A motor control system for a two-phase brushless DC motor uses measured EMF voltage from the passive set of stator coils to control commutation. A microcontroller receives the EMF voltage measurement and compares it to a threshold voltage value, which may be speed-dependent for advance commutation at high motor speeds. A match of the EMF voltage measurement with the threshold value triggers commutation of the drive to the opposite set of stator coils. The microcontroller also has an up-down counter timer whose count value is compared to an external speed reference. Each match of the count value triggers a transition in a pulse-width modulated (PWM) drive signal. The duty cycle of the PWM signal establishes an average drive voltage that controls motor speed.