US4101733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic DX signaling circuit
Assignee: Nokia of America Corp
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Filing: 1977-05-06
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Granted: 1978-07-18
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Expires: 1997-05-06
Abstract
Abstract A duplex transmission circuit using electronic components in place of either the multiple winding polar relays or combinations of differential amplifiers currently being used. In the circuit, algebraic additions and subtractions of voltage are performed and the results compared within an operational amplifier to produce the known outputs for E and M signaling in telecommunications systems. An additional operational amplifier is provided to produce a delayed response to signals of longer than a predetermined duration.
Inventors
- 👤 Donald Edward Whitaker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:33
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/38
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
186 words
A trunk signaling arrangement for a telephone system for signaling over two conductors between a first and a second office using E and M signaling techniques, a duplex trunk circuit in each office, each trunk circuit including means for transmitting the condition of its M lead over one said two conductors to the other office, a resistive balance network in each trunk circuit for sensing the condition of its M lead and the potential difference between its M lead and the M lead of the trunk circuit at the other office, an electronic comparator circuit in one trunk circuit responsive to certain predetermined combinations of conditions from said network for switching an output circuit from a quiescent to an active condition, said comparator circuit comprising an operational amplifier having two input terminals and an output terminal, and in which two substantially identical resistances of said network are coupled between the M lead of said one trunk circuit and one input terminal of said comparator circuit and in which two substantially identical resistances of said network are coupled to the other input terminal of said comparator circuit.
Claim 2
Dependent Claim
186 words
A trunk signaling arrangement for a telephone system for signaling over two conductors between a first and a second office using E and M signaling techniques, a duplex trunk circuit in each office, each trunk circuit including means for transmitting the condition of its M lead over one said two conductors to the other office, a resistive balance network in each trunk circuit for sensing the condition of its M lead and the potential difference between its M lead and the M lead of the trunk circuit at the other office, an electronic comparator circuit in one trunk circuit responsive to certain predetermined combinations of conditions from said network for switching an output circuit from a quiescent to an active condition, said comparator circuit comprising an operational amplifier having two input terminals and an output terminal, and in which two substantially identical resistances of said network are coupled between the M lead of said one trunk circuit and one input terminal of said comparator circuit and in which two substantially identical resistances of said network are coupled to the other input terminal of said comparator circuit.
Claim 3
Dependent Claim
39 words
A trunk signaling arrangement as claimed in claim 1, in which there is a symmetrical integrating circuit coupled to the output terminal of said comparator circuit to integrate the output of said comparator when switched to said active condition.
Claim 4
Dependent Claim
35 words
A trunk signaling arrangement as claimed in claim 2 in which there are further resistances coupled to the input terminals to said comparator circuit for providing a hysteresis in the switching of said comparator circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |