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:
May. 07, 2002
Filed:
Dec. 07, 2000
Tetsuo Maeda, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A malfunction-detecting-device for an EGR stepping motor is provided wherein a circuit structure is furthermore simple and also more detailed malfunction information can be obtained by detecting the malfunction of the stepping motor during initialization drive of the stepping motor when an engine is just started. In order to determine that excitation coils of the EGR stepping motor have wire breaks, a driving-signal monitoring circuit is provide for monitoring a voltage surge as a monitoring signal generated by turning off a switching element for driving each of the excitation coils so as to cause self induction in the excitation coil. Malfunction detecting means of the EGR stepping motor is also provided for counting the number of monitoring inputs to the driving-signal monitoring circuit during initialization driving of the EGR stepping motor so as to determine the presence of wire breaks in the excitation coils when the number counted is less than the number of times the coils are driven.