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:
Aug. 29, 1989
Filed:
Jun. 16, 1988
Applicant:
Inventors:
Toshiro Tojo, Kawasaki, JP;
Kenji Takato, Kawasaki, JP;
Kazumi Kinoshita, Kawasaki, JP;
Yuzo Yamamoto, Kawasaki, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 56 ; 361 42 ; 361 91 ; 361111 ; 361119 ; 379412 ;
Abstract
A protection circuit for a battery feed circuit used in a switching system. The protection circuit is comprised of: a supervising circuit for detecting an abnormal current flowing through a battery feed resistor; and a voltage limiting circuit for clamping a voltage across the battery feed resistor when the abnormal current is detected. Further, a control circuit is employed for stopping an operational amplifier, which is a component of a conventional battery feed circuit, when the abnormal current is detected.