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:
Apr. 08, 1980
Filed:
Jul. 17, 1978
Richard G Sparber, Wheaton, IL (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
A conference circuit (150) is disclosed for use in a telephone switching system (100) to provide communication among three or more subscriber stations (101, 102, 103). The subscriber stations (101, 102, 103) are connected to a plurality of ports (P0, P1, P2) of the conference circuit via communication lines (104, 105, 106) and a switching network (130). Amplification circuitry (210, 211, 212) connected to the ports (P0, P1, P2) provides input signal amplification to assure adequate transmission quality. A sensing circuit (220, 221) detects signals generated by subscriber station transitions and generates timed control signals to adjust the magnitude of amplification of input signals from the subscriber stations (101, 102, 103) for a predetermined period of time. Circuits (S1, S2) which supervise the states of junctor circuits (121, 122) connected to the conference circuit (150) provide for further gain control of the amplification circuitry (210, 211, 212). Power is supplied to the conference circuit from a junctor circuit ( 120) associated with one of the subscriber station connections.