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:
Oct. 24, 2006
Filed:
Feb. 24, 2004
Applicants:
Katsumi Ishikawa, Chiyoda-ku, JP;
Masataka Sasaki, Chiyoda-ku, JP;
Koichi Suda, Chiyoda-ku, JP;
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H 3/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A drive circuitthat controls a switching deviceON/OFF and a soft cutoff command circuit that gradually decreases the gate terminal voltage of the switching devicewhen short circuit of the switching deviceis detected. Additionally, an ON-pulse retention command circuitretains the output of the drive circuitON when the gate terminal voltage is judged to have exceeded a specified value by a gate voltage judgment comparatorthat detects the gate terminal voltage of the switching device