US4201897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ringing voltage transfer circuit
Assignee: AG Communication Systems Corp
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Filing: 1978-11-24
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Granted: 1980-05-06
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Expires: 1998-11-24
Abstract
Abstract A circuit which prepares a conductive path between a ringing voltage generator and a telephone subscriber loop circuit prior to the application of ringing voltage to the conductive path. Photo coupled switching and monitoring circuits are used to coordinate application of ringing voltage with operation of a ring relay which completes the circuit path between the ringing voltage generator and the loop circuit.
Inventors
- 👤 John P. Dorth
- 👤 Robert V. Burns
- 👤 Lloyd A. Tarr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:01
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02; H04M19/026
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
214 words
A voltage switch for connecting a source of ringing signals to a telephone subscriber station line, for use in a telephone system including a processing unit operated to generate first and second ring control signals, said voltage switch comprising: switch control means connected to said processing unit initially operated in response to said first ring control signal; first switching means connected to said switch control means operated to establish a ringing signal circuit path to said subscriber line; second switching means connected to said switch control means, operated after a predetermined time to connect said ringing signal circuit path to said source of ringing signals, conducting said ringing signals to said line; said switch control means further operated in response to said second ring control signal to render said second switch means inoperative and conditioned to render said first switch means inoperative; voltage sensing means connected between said ringing signal circuit path and said switch control means, operated in response to said rendering of said second switch means inoperative to still further operate said conditioned switch control means to render said first switch means inoperative; whereby said ringing signal source is initially connected to and further disconnected from said subscriber station only when ringing signals are not present on said ringing signal circuit path.
Claim 2
Dependent Claim
214 words
A voltage switch for connecting a source of ringing signals to a telephone subscriber station line, for use in a telephone system including a processing unit operated to generate first and second ring control signals, said voltage switch comprising: switch control means connected to said processing unit initially operated in response to said first ring control signal; first switching means connected to said switch control means operated to establish a ringing signal circuit path to said subscriber line; second switching means connected to said switch control means, operated after a predetermined time to connect said ringing signal circuit path to said source of ringing signals, conducting said ringing signals to said line; said switch control means further operated in response to said second ring control signal to render said second switch means inoperative and conditioned to render said first switch means inoperative; voltage sensing means connected between said ringing signal circuit path and said switch control means, operated in response to said rendering of said second switch means inoperative to still further operate said conditioned switch control means to render said first switch means inoperative; whereby said ringing signal source is initially connected to and further disconnected from said subscriber station only when ringing signals are not present on said ringing signal circuit path.
Claim 3
Dependent Claim
41 words
A voltage switch as claimed in claim 1, wherein: said first switching means comprise a ring relay connected to said switch control means, and a pair of make relay contacts included in said ringing signal circuit path connected to said line.
Claim 4
Dependent Claim
23 words
A voltage switch as claimed in claim 1, wherein: said second switching means comprise a triac optically coupled to a light emitting diode.
Claim 5
Dependent Claim
31 words
A voltage switch as claimed in claim 1, wherein: said voltage sensing means comprise an optically coupled transistor controlled by a pair of light emitting diodes arranged in a bipolar manner.
Claim 6
Dependent Claim
60 words
A voltage switch as claimed in claim 4, wherein: said transistor includes base and collector leads, and said voltage sensing means further comprise a capacitor connected to said base and collector leads, said capacitor operated to prevent said transistor from turning off until after an absence of current flow through said pair of light emitting diodes for a predetermined period.
Claim 7
Dependent Claim
148 words
A voltage switch as claimed in claim 1, wherein said switch control means comprise: a first flip-flop circuit connected to said processing unit, to said voltage sensing means and to said first switching means, operated in response to said first ring control signal from said processing unit to energize said first switching means; a second flip-flop circuit connected to said processing unit, to said first flip-flop circuit and to said second switching means operated in response to said first ring control signal and operation of said first flip-flop to energize said second switching means after a predetermined period; said second flip-flop circuit further operated in response to said second ring control signal from said processing unit to de-energize said second switching means; and said first flip-flop circuit further operated in response to said second ring control signal and said voltage sensing means to de-energize said first switching means.
References Cited (Backward Citations)
US3536852A
Cited
US3941939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-05-06 | 1983-11-05 | 1984-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-06 | 1987-11-05 | 1988-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-06 | 1991-11-05 | 1992-05-06 | $7700.00 | Window Closed / Lapsed |