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:
Jan. 27, 1987
Filed:
Dec. 18, 1984
Kazuo Kuroki, Tokyo, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
In the particular embodiment of the invention described in the specification, a circuit for interrupting the operation of a switching transistor includes a reactor connected in series with the transistor emitter and a plurality of diodes connected in series between the reactor and the base of the transistor so that the electromotive force induced in the reactor when the reactor current decreases is supplied to the base of the transistor. This makes it possible to maintain the reactor storage time when the transistor is switched off and to adjust the fall time so that the changing rate (di/dt) of the current flowing in a snubber circuit for controlling overvoltage may be minimized so that the structural restrictions imposed on the snubber circuit can be eased and reliability is improved. Noise is also reduced because the current drop rate (-di/dt) when the transistor is switched off can be minimized.