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:
Dec. 15, 1981
Filed:
Sep. 14, 1979
Applicant:
Inventors:
Assignee:
Le Materiel Telephonique Thomson-CSF, Paris, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ;
Abstract
A telephone set line circuit ringing current injection device having a hybrid circuit in which each feed wire is connected in series with a resistor, and a stage consisting of a diode connected in parallel with the collector-to-emitter circuit of a transistor. The cathode of one diode is connected to the collector of the transistor on the side of one of the feed wires, the anode of the other diode and the emitter of the other transistor are connected to the other wire.