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:
Nov. 04, 1997
Filed:
Nov. 13, 1995
Tetsuo Yagyu, Yokohama, JP;
Takahiro Watai, Kawasaki, JP;
Hirokazu Tanaka, Kawasaki, JP;
Tetsuji Funaki, Kawasaki, JP;
Kunihiko Gotoh, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A ringtrip judging circuit includes a single comparator for comparing a detection value of a ringing current with a threshold value and for outputting the result of the comparison, a threshold value control circuit for supplying the threshold value to the comparator, and a judging circuit for judging ringtrip based on the output of the comparator. During a prescribed period after ringing signal transmission, the threshold value control circuit changes the threshold value in a steplike manner in accordance with the result of the comparison, thereby determining a threshold value greater than a peak value during the prescribed period, and based on it, determines a threshold value for ringtrip judgement and supplies it to the comparator.