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:
Aug. 09, 2011
Filed:
Feb. 11, 2009
Tamotsu Yamaura, Atsugi, JP;
Kenichi Hamada, Atsugi, JP;
Yutaka Makino, Chigasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A failure detection apparatus for a resolver outputting a sine signal indicative of sin θ and a cosine signal indicative of cos θ according to a rotational angle θ of a rotator, includes an inspection value calculating section configured to calculate an inspection value based on at least one of the sine signal and the cosine signal; a failure detecting section configured to judge whether the resolver is in a failure state or not on the basis of the inspection value; a counting section configured to gradually increase a count value with a lapse of time when the failure detecting section is determining that the resolver is in the failure state, and configured to gradually decrease the count value with a lapse of time when the failure detecting section is determining that the resolver is not in the failure state; and a failure deciding section configured to finally decide that the resolver has caused the failure on the basis of the count value.