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:
Jan. 09, 1979
Filed:
Dec. 23, 1977
Applicant:
Inventors:
David Q Lee, Chicago, IL (US);
Richard M Rovnyak, Schaumburg, IL (US);
Assignee:
GTE Automatic Electric Laboratories Incorporated, Northlake, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ;
Abstract
An AC supervisory signal detector circuit for use in conjunction with a trunk circuit of a digital PABX telephone system interfacing with a central office providing for detection of relatively low frequency AC voltages which may be superimposed upon a DC bias voltage of either polarity. The circuit is equally responsive to various frequencies used in supervisory type signaling.
Lee, David. (1979). Ac supervisory signal detector circuit (U.S. Patent No. 4133982). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4133982
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile