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.

Date of Patent:
Nov. 25, 2003

Filed:

Feb. 20, 2002
Applicant:
Inventor:

Takashi Furui, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B60R 2/101 ;
U.S. Cl.
CPC ...
B60R 2/101 ;
Abstract

When an on-board power source is turned off, after a predetermined time has elapsed, a microcomputer writes predetermined data in a nonvolatile memory and when the on-board power source is turned on, the microcomputer judges whether the predetermined data is written in the nonvolatile memory or not. If the judgment shows that the predetermined data is not written in the nonvolatile memory the microcomputer determines a backup capacitor not to be working normally. The predetermined time is shorter than the operating time of the microcomputer determined by the discharge time of the backup capacitor when the backup capacitor is working normally, and is longer than the operating time of the microcomputer determined by the discharge time of the backup capacitor when the backup capacitor is not working normally.


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