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. 02, 1977
Filed:
Mar. 17, 1976
Applicant:
Inventor:
Jean A Picandet, Paris, FR;
Assignee:
Jeumont-Schneider, Puteaux, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
1791 / ;
Abstract
An electronic replacement for a telephone transformer for connecting a two-wire circuit to a four-wire circuit comprises a first differential amplifier having a constant gain feedback loop. The feedback loop comprises an opto-electronic coupler and a second differential amplifier. A DC source connected to the first differential amplifier by a switch produces biasing current for a photo transistor in the opto-electronic coupler. A DC supply to the line on the two-wire side is provided by a source connected to the wires by transistor circuits connected as active reactances.