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:
Mar. 21, 2006
Filed:
Mar. 03, 2005
Applicants:
Jeffrey Ronald Coles, Solihull, GB;
Connel Williams, Leamington Spa, GB;
Inventors:
Jeffrey Ronald Coles, Solihull, GB;
Connel Williams, Leamington Spa, GB;
Assignee:
TRW Limited, , GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 3/18 (2006.01);
U.S. Cl.
CPC ...
Abstract
A drive system for a three phase brushless motor uses an algorithm for position sensing which measures the inductance in the motor phases and determines the position from the measured inductances. In order to reduce acoustic noise, the inductances are measured during test periods T, which are conducting states added to the PWM pattern in each PWM period. The test periods have net voltage of zero and therefore do not affect the output of the motor, but are sufficiently long to allow inductance measuring as well as the use of a single current sensor for current sensing.