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:
Sep. 12, 1989
Filed:
Oct. 02, 1987
Hiromi Iwai, Kanagawa, JP;
Masatoshi Nakajima, Kanagawa, JP;
Hiroshi Asaga, Kanagawa, JP;
Nobuyuki Takao, Kanagawa, JP;
Satoru Shiga, Kanagawa, JP;
Yoshihiro Tanabe, Kanagawa, JP;
Fuji Electric Co., Ltd., Kanagawa, JP;
Abstract
A method of diagnosing the deterioration of a zinc oxide type lighting arrester having one or more series-connected non-linear resistance elements including steps of elimination of the effects of capacitive currents from phase currents; obtaining a synthesized waveform using a window type transformer based on the resistance elements alone; and diagnosing the presence of a deteriorated non-linear resistance element by generating a first pulse voltage when the maximum crest value of the synthesized waveforms exceeds a predetermined value, generating a second pulse voltage representative of terminal voltage of the resistance element, and calculating the difference between the first and second pulse voltages.