Telephonic communications – Subscriber line or transmission line interface
Patent
1995-05-26
1998-12-08
Tsang, Fan S.
Telephonic communications
Subscriber line or transmission line interface
379350, 379373, 379377, H04M 174
Patent
active
058481494
ABSTRACT:
A subscriber line circuit which truly implements all of the BORSCHT functions and which does not rely on an external ringing generator to provide the ringing voltage when needed is disclosed. This implementation is achieved by recognizing that supervisory and ringing signals occur in some sort of sequence and, therefore, do not have to be generated simultaneously. Based on this recognition, we provide a circuit which truly implements all of the BORSCHT functions and includes a power section that generates each of the supervisory signals, e.g., -48 volts and -24 volts, and alerting signal, e.g., ringing signal, in turn and as required.
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Chen Robert K.
Frazier Paul W.
Gammel John C.
Marsh Andrew J.
Roy Apurba
Lucent Technologies - Inc.
Luludis Frederick B.
Saint-Surin Jacques M.
Tsang Fan S.
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