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:
Apr. 03, 2007
Filed:
Oct. 26, 2004
Hisashi Kameya, Kariya, JP;
Hisashi Kameya, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
A motor driving system for an electric motor includes a pulse width modulating circuit which provides driving pulse signals whose pulse width is modulated to have a prescribed duty ratio, an inverter having PWM-controlled switch elements, a voltage calculating circuit which calculates levels of voltage to be respectively applied between the power source and the phase windings, a current calculating circuit which calculates reference values of current of the inverter from levels of the voltage applied between the power source and the phase windings of the electric motor and resistances disposed between the power source and the phase windings, a current detecting circuit which detects actual values of current of the inverter, and a processor which judges abnormality if one of the actual value of current of the inverter is a preset value different from corresponding one of the reference values.