1980-09-04
1982-11-23
Robinson, Thomas A.
H04M 322, H04B 346
Patent
active
043607098
ABSTRACT:
A circuit for detecting a closed loop formed by actuation of a telephone set, the loop being indicative of a connection between the telephone set and an exchange through a ring line and a tip line. The detecting circuit comprises generators for generating first and second detection signals having amplitudes proportional to a ring line current and a tip line current respectively, a summing circuit for summing the detection signals and a comparator for comparing the outputs of the summing circuit and a reference value and delivering an output depending upon the result of comparison.
REFERENCES:
patent: 3622709 (1971-11-01), Tjaden
patent: 4079208 (1978-03-01), Rogers et al.
patent: 4099032 (1978-07-01), Roge et al.
Hamazato Kazuo
Kitano Junjiro
Takeshita Tetsuo
Hitachi , Ltd.
Nippon Telegraph & Telephone Public Corporation
Robinson Thomas A.
LandOfFree
Loop detecting 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 Loop detecting circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Loop detecting circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1880398