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. 20, 2010
Filed:
Aug. 01, 2007
Akira Serizawa, Shizuoka, JP;
Byungeok Seo, Shizuoka, JP;
Akira Serizawa, Shizuoka, JP;
Byungeok Seo, Shizuoka, JP;
Yazaki Corporation, Tokyo, JP;
Abstract
The present invention provides an apparatus and a method for accurately detecting abnormal conditions of a motor. A ΔTc/Tj detector detects a difference (ΔTc) between an environment temperature and a temperature of a field-effect transistor (FET) which turns on and off electric power supplied to a DC motor. A diagnosis control unit detects abnormal conditions such as a motor lock and a short circuit of the DC motor based upon the obtained difference. When the motor lock has been detected, the diagnosis control unit controls a pulse width modulation (PWM) control unit and a PWM oscillator (PWMOSC) and makes a frequency and duty cycle of a PWM signal lower. When the short circuit has been detected, the diagnosis control unit controls a gate driver and turns off the FET.