Patent US4980911A successfully refreshed from Google Patents.
US4980911A
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Transient signal elimination circuit for telecommunications applications with CPU control means
Assignee: Inteleplex Corp
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Filing: 1989-07-11
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Granted: 1990-12-25
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Expires: 2009-07-11
Abstract
Abstract Transient signal elimination circuitry is disposed in a local communications loop extending from a subscriber telephone to a telephone central office couples ringing and on-hook and off-hook signals through the loop after removing transients in these signals. The circuitry also isolates the telephone subscriber and central office from the local loop until an off-hook signal is detected and restores this isolation when an on-hook condition exists at the telephone subscriber. Transient signal elimination is accomplished with a CPU driven interface which detects undesirable transients such as a ringing or off-hook signal, and in response thereto generates a burst of double tone signal to alert connected equipment. In this manner, the local loop can be simultaneously used for both voice communications and a second information signal with each signal capable of occupying the same bandwidth. These signals can operate independently of each other.
Inventors
- 👤 John M. Sues
- 👤 Jing H. Sun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:47
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/78; H04M11/00; H04M11/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
98 words
Apparatus for use in a communications loop connecting a subscriber telephone to a telephone central office, said apparatus comprising means for receiving different incoming signals and providing a multi-tone output signal associated with each of said incoming signals, said receiving means also eliminating an undesirable transient present in a predetermined one of said incoming signals so that none of the output signals include the undesirable transients, and CPU driven control means responsive to a certain one of said incoming signals received by said receiving means for generating said multi-tone output signals associated with each of said input signals.
Claim 2
Dependent Claim
98 words
Apparatus for use in a communications loop connecting a subscriber telephone to a telephone central office, said apparatus comprising means for receiving different incoming signals and providing a multi-tone output signal associated with each of said incoming signals, said receiving means also eliminating an undesirable transient present in a predetermined one of said incoming signals so that none of the output signals include the undesirable transients, and CPU driven control means responsive to a certain one of said incoming signals received by said receiving means for generating said multi-tone output signals associated with each of said input signals.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein said first and second terminals are each a pair of terminals.
Claim 4
Dependent Claim
18 words
The apparatus of claim 1 wherein said incoming signals are received on said first and said second terminals.
Claim 5
Dependent Claim
46 words
The apparatus of claim 1 wherein said predetermined one of said incoming signals is a ringing signal coupled to said communications loop by said telephone central office and destined for said subscriber telephone and said receiving means eliminates an undesirable transient present in said ringing signal.
Claim 6
Dependent Claim
47 words
The apparatus of claim 1 wherein each of said predetermined one of said incoming signals is a signal indicating an off-hook condition at said subscriber telephone and destined for said telephone central office and said receiving means eliminates an undesirable transient present in the off-hook indicating signal.
Claim 7
Dependent Claim
25 words
The apparatus of claim 1 wherein said predetermined one of said incoming signals and said certain one of said incoming signals represent the same information.
Claim 8
Dependent Claim
24 words
The apparatus of claim 1 wherein said predetermined one of said incoming signals and said certain one of said incoming signals represent different information.
Claim 9
Dependent Claim
26 words
The apparatus of claim 1 wherein said certain one of said incoming signals is associated with a signal indicating an off-hook condition at said subscriber telephone.
Claim 10
Dependent Claim
26 words
The apparatus of claim 1 wherein said another one of said incoming signals is associated with a signal indicating an on-hook condition at said subscriber telephone.
Claim 11
Dependent Claim
54 words
The apparatus of claim 1 wherein said CPU driven control means further includes means responsive to a certain one of said incoming signals for closing a normally open first circuit path extending between first and second terminals of said apparatus and responsive to another one of said incoming signals for reopening said circuit path.
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) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |