Browse Prior Art Database

Conference Circuit

IP.com Disclosure Number: IPCOM000091486D
Original Publication Date: 1968-Feb-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Cozza, LM: AUTHOR [+2]

Abstract

This conference circuit is for a multiplexed, time-division, switching telephone system in which any one phone is connected to a common transmission bus during only a short interval forming a time slot of a periodic sampling cycle. Such system of this type has a number of Line Busses 10. Each bus has a plurality of individual telephone lines 11 connected to it through Time Division Gate 12. Interbusses 13 connect, through Gates 14, any pair of Busses 10 together for communication between telephones connected to different Busses 10. A Clamp Circuit 15 is connected to each Interbus 13. Switching Control 16 is connected to all Gates 12 and 14 to control interconnection of phone lines 11.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 61% of the total text.

Page 1 of 2

Conference Circuit

This conference circuit is for a multiplexed, time-division, switching telephone system in which any one phone is connected to a common transmission bus during only a short interval forming a time slot of a periodic sampling cycle. Such system of this type has a number of Line Busses 10. Each bus has a plurality of individual telephone lines 11 connected to it through Time Division Gate 12. Interbusses 13 connect, through Gates 14, any pair of Busses 10 together for communication between telephones connected to different Busses 10. A Clamp Circuit 15 is connected to each Interbus 13. Switching Control 16 is connected to all Gates 12 and 14 to control interconnection of phone lines 11. Connection of two phones on the same bus takes place for short intervals at a repetition rate of about twice the highest audio frequency to be transmitted. If the phones are on different Busses 10, the latter are connected by Interbusses 13 with the Clamps 15 maintaining a sampling voltage if the phones are connected to their Busses 10 at different sample times.

For a conference connection between three or four telephones, Control 16 assigns two separate sampling times and one Conference Bus 17 to the conference connection. Each Bus 17 has a series resonant Circuit 18 connected to it to store a portion of the audio energy supplied by the connected phones. If all of the conference phones are on the same Bus 10, they are connected in pairs in each of the two assigne...