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:
May. 17, 2005
Filed:
Mar. 04, 2004
Takao Takehara, Tokyo, JP;
Takao Takehara, Tokyo, JP;
Minebea Co., Ltd., Nagano-ken, JP;
Abstract
An A/D converter converts a sine and cosine wave output of a resolver to form a digital sine and cosine. A microcomputer uses an absolute value of digital sin θ as an address to retrieve θ from a memory containing angle values between 0° and 90°, if the absolute value of sin θ is between 0 and 0.707. Otherwise, if the absolute value of sin θ is between 0.707 and 1, cos θ is used as an address to retrieve θ. The polarities of sin θ and cos θ are used to determine a quadrant and an associated offset including 0°, 180°−θ, 180°+θ, and 360°−θ, which is combined with θ such that the final angle of the rotor axis is obtained.