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:
Jul. 02, 2019

Filed:

Jun. 13, 2016
Applicant:

Mitsubishi Electric Corporation, Tokyo, JP;

Inventors:

Shiori Uota, Tokyo, JP;

Fumitaka Tametani, Tokyo, JP;

Takahiro Inoue, Tokyo, JP;

Rei Yoneyama, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 31/26 (2014.01); H01L 27/06 (2006.01); H01L 29/16 (2006.01); H01L 29/739 (2006.01); H01L 29/861 (2006.01); G01R 31/42 (2006.01); H03K 17/18 (2006.01);
U.S. Cl.
CPC ...
G01R 31/2642 (2013.01); G01R 31/42 (2013.01); H01L 27/0635 (2013.01); H01L 29/16 (2013.01); H01L 29/1608 (2013.01); H01L 29/7393 (2013.01); H01L 29/861 (2013.01); G01R 31/2608 (2013.01); G01R 31/2632 (2013.01); H03K 17/18 (2013.01);
Abstract

A life estimation circuit includes a temperature detector configured to detect temperature of a power element unit, an inflection point detection unit configured to detect an inflection point of temperature variation in the power element unit based on an output signal from the temperature detector, an operation unit configured to determine an absolute value of a difference between the temperature of the power element unit at an inflection point detected this time and the temperature of the power element unit at an inflection point detected last time, a count circuit configured to count the number of times that the absolute value of the difference in temperature has reached a threshold temperature, and a signal generation unit configured to output, when a count value from the count circuit reaches a threshold number of times, an alarm signal indicating that the power element is about to reach the end of its life.


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