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. 12, 2007
Filed:
Sep. 29, 2005
Applicants:
Mark E Collins, Webster, NH (US);
Sumner B Marshall, Iii, Webster, MA (US);
Inventors:
Mark E Collins, Webster, NH (US);
Sumner B Marshall, III, Webster, MA (US);
Assignee:
Asahi Kasei Microsystems Co., Ltd., Shinjuku-ku, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P 7/06 (2006.01);
U.S. Cl.
CPC ...
Abstract
A system and method for reducing fan noise by controlling the drive current to the fan motor. In one embodiment the system approximates a linear drive using a number of transistors in parallel and sequentially deploying the transistors. In another embodiment, a scheme is used to activate and deactivate transistors in discrete steps thereby achieving the benefits of the linear controller topology.