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. 28, 1987
Filed:
Jun. 28, 1985
Applicant:
Inventors:
Kazuhiro Sato, Yokohama, JP;
Hiroyoshi Mori, Yokohama, JP;
Assignee:
Fujitsu Limited, Kanagawa, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 58 ; 361 94 ; 361 98 ; 361101 ;
Abstract
An overcurrent protection circuit including a first transistor, a second transistor, and an integrator. The first transistor operates to control a current flow from a power source to a load. The second transistor is turned on when an overcurrent flows through the first transistor. The overcurrent is detected by watching the collector-emitter voltage of the first transistor. Thus, the second transistor operates to bypass the base current to be supplied to the first transistor with a certain delay time defined by a delay part, which enables an instantaneous overcurrent to be ignored.