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:
Jul. 29, 2014
Filed:
Oct. 07, 2011
Yasuhiro Kawanaka, Chiyoda-ku, JP;
Takahiro Okanoue, Chiyoda-ku, JP;
Yasuhiro Kawanaka, Chiyoda-ku, JP;
Takahiro Okanoue, Chiyoda-ku, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An electric power steering device includes: a fail-safe power relay () and a motor relay () for interrupting power supply to an electric-motor driving unit for driving an electric motor for applying an assist torque for steering performed by a driver; and a relay driving circuit () including a switch () connected in parallel to drive coils of the relays (and) and a diode (). A target value of a relay-contact energizing current is lowered and the relays (and) are gradually interrupted while an amount of current corresponding to a back surge generated when the relays are turned OFF is caused to flow back to the diode () of the relay driving circuit () in a normal relay-OFF operation, whereas the relays (and) are quickly interrupted without operating the relay driving circuit () in case of detection of an abnormality.