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. 28, 2000
Filed:
Jun. 05, 1997
Fuyuki Maehara, Kariya, JP;
Yasuhiro Takase, Kariya, JP;
Wakako Kanazawa, Toyokawa, JP;
Tadatoshi Asada, Anjo, JP;
Hiroaki Ishikawa, Nagoya, JP;
Toshinori Maruyama, Anjo, JP;
Denso Corporation, Kariya, JP;
Abstract
A permanent magnet made of ferrite magnet material used for a generator may be irreversibly demagnetized by a factor such as current supplied to a field coil, temperature of the permanent magnet and/or output current of an armature coil. When the field current exceeds a preset value, and also the output current exceeds a preset value, the field current is limited to prevent the irreversible demagnetization. Thus, the irreversible demagnetization of the permanent magnet can be prevented, while ensuring a sufficient amount of the output power. It is also effective that the field current or armature current is limited when the temperature of the permanent magnet is in a range of possible irreversible demagnetization.