US3725612A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Echo suppressor break-in circuit
Assignee: Comsat Corp
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Filing: 1971-05-14
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Granted: 1973-04-03
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Expires: 1991-05-14
Abstract
Abstract Split, switching type echo suppressors with break-in circuitry having dual control of the two break-in switches. At break-in each break-in switch is independently and simultaneously operated for the break-in state. After cessation of break-in each break-in switch is maintained for different hangover periods before reverting to the non-break-in state.
Inventors
- 👤 S Campanella
- 👤 H Suyderhoud
- 👤 M Onufry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:17
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
196 words
In a communication system having a pair of terminals, each terminal having means for interconnecting a two wire circuit with a four-wire transmission facility, an improved echo suppressor apparatus including means for detecting incoming speech on the receive side of said terminal, first switch means responsive to said incoming speech detecting means for disconnecting the send side of said terminal, means for detecting the presence of outgoing speech at said terminal while said incoming speech is present at said terminal, second switch means responsive to said means for detecting the presence of outgoing speech for reconnecting the send side of said terminal and means responsive to the detection of said outgoing speech for attenuating said incoming speech, wherein the improvement comprises: a. third switch means responsive to said means for detecting the presence of outgoing speech for disconnecting the send side of said terminal a first predetermined time interval after said outgoing speech has ceased; and b. fourth switch means responsive to said sensing means for removing said attenuation means from said incoming signals a second predetermined time interval after said outgoing speech has ceased said second time interval being independent of said first time interval.
Claim 2
Dependent Claim
196 words
In a communication system having a pair of terminals, each terminal having means for interconnecting a two wire circuit with a four-wire transmission facility, an improved echo suppressor apparatus including means for detecting incoming speech on the receive side of said terminal, first switch means responsive to said incoming speech detecting means for disconnecting the send side of said terminal, means for detecting the presence of outgoing speech at said terminal while said incoming speech is present at said terminal, second switch means responsive to said means for detecting the presence of outgoing speech for reconnecting the send side of said terminal and means responsive to the detection of said outgoing speech for attenuating said incoming speech, wherein the improvement comprises: a. third switch means responsive to said means for detecting the presence of outgoing speech for disconnecting the send side of said terminal a first predetermined time interval after said outgoing speech has ceased; and b. fourth switch means responsive to said sensing means for removing said attenuation means from said incoming signals a second predetermined time interval after said outgoing speech has ceased said second time interval being independent of said first time interval.
Claim 3
Dependent Claim
52 words
The apparatus of claim 1 wherein said third switch means includes an RC time circuit wherein said first predetermined time period is determined by a first constant R1C1 and said fourth switch means includes a second RC time circuit wherein said second predetermined time period is determined by a second constant R2C2.
Claim 4
Dependent Claim
26 words
The apparatus of claim 2 wherein said second predetermined time interval is equal to the overall time delay of speech in the four wire transmission facility.
Claim 5
Dependent Claim
87 words
The apparatus of claim 3 wherein said means for sensing the presence of outgoing speech comprises a differential amplifier, and said second switch means comprises a second switch in parallel with said first switch means and second switch control means responsive to said differential amplifier for causing said second switch to bypass said first switch means upon detection of the presence of outgoing speech by said differential amplifier and causing said second switch to open-circuit upon detection of the cessation of outgoing speech by said differential amplifier.
Claim 6
Dependent Claim
88 words
The apparatus of claim 4 wherein said means for attenuating comprises a loss pad in the receive side of said terminal and said fourth switch means comprise a fourth switch in parallel with said loss pad and fourth switch control means responsive to said differential amplifier for inserting said loss pad into the receive side of said terminal upon detection of the presence of outgoing speech by said differential amplifier and bypassing said loss pad upon the detection of the cessation of outgoing speech by said differential amplifier.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |