Patent
1981-09-21
1983-08-02
Brown, Thomas W.
179 84A, H04M 306, H04M 322
Patent
active
043968058
ABSTRACT:
A ring trip detector for a subscriber line interface circuit which couples a two-wire subscriber line with the transmitting and receiving branches, respectively, of a four-wire line in a telecommunication exchange. The subscriber line interface circuit includes a two-to-four wire hybrid circuit having an off-hook detector; a ring generator for producing an AC ring voltage of given frequency for ringing a subscriber set connected to the subscriber line; and a ring relay for selectively connecting the hybrid circuit to the subscriber line when in a first position and connecting the ring generator to the subscriber line when in a second position. The ring trip detector includes a first circuit, which receives a first signal representing the off-hook condition of the subscriber set and a second signal that is synchronized with zero crossings of said ring voltage, for producing a synchronized off-hook signal at the next, subsequent zero crossing of the ring voltage after said first signal indicates the presence of the off-hook condition; and a second circuit, which receives the synchronized off-hook signal, for switching the relay to its first position.
REFERENCES:
patent: 4110569 (1978-08-01), Schindler et al.
patent: 4199664 (1980-04-01), Grange et al.
patent: 4320260 (1982-03-01), Lechner
Brown Thomas W.
Milde Jr. Karl F.
Siemens Corporation
LandOfFree
Ring trip detector for a subscriber line interface circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ring trip detector for a subscriber line interface circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ring trip detector for a subscriber line interface circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-485296