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. 22, 2008
Filed:
Aug. 23, 2006
Hideaki Kawada, Gunma, JP;
Yuho Aoki, Gunma, JP;
Hideaki Kawada, Gunma, JP;
Yuho Aoki, Gunma, JP;
NSK Ltd., Tokyo, JP;
Abstract
The present invention includes a control part for controlling switching elements on diagonal lines in the upper and lower stage of an H bridge circuit respectively by different duty ratios based on a steering torque exerted on a steering system, and an electric power supply source for supplying an electric power. When the voltage of the electric power supply source is lower than a prescribed voltage, the control part causes the switching element EETor FETon the upper-stage side to be driven by a pulse width modulation signal PWMor PWM, the switching element FETor FETon the lower-stage side to be turned on, and the frequency of the pulse width modulation signal to be lowered to an audible frequency range.