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:
Mar. 06, 1979
Filed:
Oct. 25, 1977
Applicant:
Inventors:
Makoto Yoshitoshi, Musashino, JP;
Isao Kawashima, Yokosuka, JP;
Hideo Kishimoto, Yokohama, JP;
Masaaki Terai, Yokohama, JP;
Kazumi Kato, Hino, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ;
Abstract
There are provided a current detecting resistance element connected in series with a loop for supplying current to a telephone set, a switching circuit including a three terminal semiconductor switching element connected to be ON.OFF controlled by the voltage drop across the resistance element, and an impedance element controlled by the ON.OFF operation of the switching element to be connected across the loop for adding AC loss.