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. 25, 1981
Filed:
Oct. 30, 1979
Kiyoshi Nakamura, Ibaraki, JP;
Hiroaki Ishikawa, Kawasaki, JP;
Hisakatsu Kiwaki, Ibaraki, JP;
Fumio Ogata, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A direct current detecting device is disclosed in which two pairs of saturable cores are provided so as to enclose a conductor carrying a direct current to be measured. On each of the saturable cores, a bias winding, a feedback winding and an output winding are wound. First and second output circuits are provided, each connected with a pair of output windings and each including two closed current paths consisting of the output winding, a common load, a common A.C. supply source and a diode. The diodes function to allow the greater one of current flows of the two closed paths to be passed through the common load. An amplifier is connected to receive the difference between output signals of the two output circuits. The output of the amplifier is supplied to the feedback winding whereby the magnitude of the feedback current becomes a function of the magnitude of the current flowing through the conductor.