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:
Apr. 06, 1993
Filed:
Jul. 12, 1991
Kiyoaki Sasagawa, Kanagawa, JP;
Hiroshi Miki, Kanagawa, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
A drive circuit for a current sense IGBT having, in addition to a fault discrimination operational circuit for detecting an overcurrent of the current sense IGBT, a capacitor operatively connected in parallel to the gate-emitter of the current sense IGBT, and a transistor for discharging the capacitor via a resistor. In case of short-circuit fault, an overcurrent is detected by the fault discrimination operational circuit, and the transistor is turned on via the operational circuit. The gate voltage of the IGBT is gradually declined to turn off the IGBT. This enables the IGBT to be protected from a transitional overvoltage across the collector and emitter of the IGBT.