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:
Jul. 03, 1984
Filed:
Apr. 09, 1982
Applicant:
Inventor:
Takashi Iida, Tokyo, JP;
Assignee:
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 76 ; 361 93 ;
Abstract
A static protective relay at least includes a plurality of current transformers inserted in poly-phase AC power lines, a half-wave rectifying circuit for rectifying the output voltages from said current transformers, wave-shaping circuits for wave-shaping two of the pulsate output voltages from the half-wave rectifying circuit into rectangular wave output voltages, and a negative phase failure detecting circuit including a data flip-flop for detecting the level of the rectangular wave output to be phase-retarded at the instant of rising up of the rectangular wave output to be phase-advanced.