US3651271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement including a relaxation oscillator for alternately providing ringing-tone and supervisory signals to subscriber stations
Assignee: International Standard Electric Corp
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Filing: 1970-04-09
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Granted: 1972-03-21
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Expires: 1990-04-09
Abstract
Abstract A loop current supervisory device and a central tone generator are coupled to a line leading to a called subscriber. Each is alternately rendered operative via a central astable relaxation oscillator. Thus loop current supervision and the ringing phase are clearly separated from each other.
Inventors
- 👤 Hans-Ulrich Knauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:46
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02; H04M19/04; H04M19/026
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
94 words
A circuit arrangement for providing ringing tone to subscriber stations equipped with ringing-tone receivers and for providing answer supervision of said subscriber stations, said arrangement comprising a telephone exchange station coupled to a loop current supervisory device and to a central ringing-tone generator, an astable relaxation oscillator having two output terminals, means coupling said ringing tone generator to one output terminal and said loop current supervisory device to the other output terminal, said oscillator providing energization signals alternately to said respective terminals to alternately supply ringing tone and supervisory service to a called subscriber.
Claim 2
Dependent Claim
94 words
A circuit arrangement for providing ringing tone to subscriber stations equipped with ringing-tone receivers and for providing answer supervision of said subscriber stations, said arrangement comprising a telephone exchange station coupled to a loop current supervisory device and to a central ringing-tone generator, an astable relaxation oscillator having two output terminals, means coupling said ringing tone generator to one output terminal and said loop current supervisory device to the other output terminal, said oscillator providing energization signals alternately to said respective terminals to alternately supply ringing tone and supervisory service to a called subscriber.
Claim 3
Dependent Claim
28 words
A circuit arrangement according to claim 1, in which the astable relaxation oscillator is designed to produce energization signals of equal duration and oscillates at a selected frequency.
Claim 4
Dependent Claim
56 words
A circuit arrangement according to claim 1, characterized in that current from each of a plurality of loop current supervisory devices is applied at a first input of a corresponding AND-gate, all of the gates being rendered operative by application of current through a common connection to a second input terminal from the astable relaxation oscillator.
Claim 5
Dependent Claim
35 words
A circuit arrangement according to claim 1, in which each of a plurality of lines leading to a called subscriber Station is coupled to the output of a central ringing-tone generator via separate connecting contacts.
Claim 6
Dependent Claim
32 words
A circuit arrangement according to claim 1, in which the central ringing-tone generator is switched on and off via a separate switch controllable by an output signal of the astable relaxation oscillator.
Claim 7
Dependent Claim
21 words
A circuit arrangement according to claim 5, in which supply voltage for the central ringing-tone generator is connected via the switch.
Claim 8
Dependent Claim
86 words
A circuit arrangement according to claim 1, in which for supervising the loop current, a supervisory circuit employing a plurality of supervisory switches is connected in parallel to a feeding bridge of the line, which supervisory switches, at a loop closure, provide the first input to a supervisory AND-circuit whose second input is provided by a central astable relaxation oscillator, such that when the inputs to the AND-circuit energize it a signal indicating that a called subscriber has answered appears at the output of said AND-circuit.
Claim 9
Dependent Claim
40 words
A circuit arrangement according to claim 3, including a plurality of AND-gates, means coupling the second inputs of said AND-gate representing different loop current supervisory devices in parallel and to the associated switching stage of the central astable relaxation oscillator.
Claim 10
Dependent Claim
35 words
A circuit arrangement according to claim 4, in which the ringing-tone signal of the ringing-tone generator is, via a separate winding of a line transformer, applied to the line leading to the called subscriber station.
References Cited (Backward Citations)
US3492437A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |