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:
Jun. 09, 2009
Filed:
Apr. 06, 2007
Connel Brett Williams, Leamington Spa, GB;
Jiang LI, Birmingham, GB;
Connel Brett Williams, Leamington Spa, GB;
Jiang Li, Birmingham, GB;
TRW Limited, , GB;
Abstract
A drive system for a multi-phase brushless motor comprises a single current sensor drive circuit, including switch means, switchable between a plurality of states. A controller is arranged to provide pulse width modulated drive signals to control the switch means so as to control the time that the drive circuit switches between said states in each of a series of pulse width modulation periods, and to: determine a demanded voltage parameter set, identify PWM periods during which the demanded voltage parameter set is such that neither two nominal corresponding state times, nor a higher number of equivalent state times producing the same net voltage, in a single PWM period, would allow a predetermined minimum time to be spent in a predetermined number of active states sufficient for current sensing. For such PWM periods, modified state times are calculated that do allow sufficient time to be spent in a sufficient number of active states for the current in each of the phases to be determined by means of the current sensor.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile