Patent US5853465A successfully refreshed from Google Patents.
Patent US3748400A successfully refreshed from Google Patents.
US3748400A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for attenuation compensation in telecommunication subscriber stations
Assignee: Siemens and Halske AG
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Filing: 1972-07-20
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Granted: 1973-07-24
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Expires: 1992-07-20
Abstract
Abstract The invention is related to a circuit arrangement for centrally supplied subscriber stations in telecommunication installations. In the inventive circuit the recieving amplifier is connected into a bridge circuit used for side-tone attenuation. The signal input of the receiving amplifier is located in the one diagonal of the bridge, and the output of the transmitter is located in the other diagonal of the bridge circuit. A variable resistance element is connected in parallel with the bridge diagonal across which the signal input to the receiving amplifier appears for compensating for the different attenuation affects of transmission lines having differing lengths.
Inventors
- 👤 H Ritz
- 👤 H Gorlitz
- 👤 A Jendis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:04
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/58; H04M1/585
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
170 words
In a circuit arrangement for centrally supplied telecommunication subscriber stations having a bridge circuit for side tone suppression wherein a receiver amplifier receives its input across one diagonal of said bridge circuit, the subscriber station transmitter being connected across the other diagonal of said bridge circuit, an improvement comprising: variable resistance means for compensating for the different attenuation effects of transmission lines of different lengths, said variable resistance means being connected in parallel with said one diagonal of said bridge circuit in such a manner that the frequency characteristic of said bridge circuit is not altered with variation of said variable resistance means and in such a manner that the operating point of said receiving amplifier is not altered with variation of said variable resistance means. @. The circuit arrangement of claim 1 wherein said variable resistance means is direct current coupled to said one diagonal of said bridge circuit and wherein direct current decoupling means is inserted between said variable resistance means and the input to said receiving amplifier.
Claim 2
Dependent Claim
38 words
The circuit arrangement of claim 1 further comprising means for varying the internal resistance of said amplifier in correspondence with variations of said variable resistance means so that the frequency response of said amplifier is held substantially constant.
Claim 3
Dependent Claim
16 words
The circuit arrangement of claim 3 wherein said subscriber station receiving circuit includes a capacitive transducer.
Claim 4
Dependent Claim
14 words
The circuit arrangement of claim 1 wherein said variable resistance means is a diode.
Claim 5
Dependent Claim
33 words
The circuit arrangement of claim 1 further comprising means for maintaining the supply voltage from the subscriber line applied to said receiving amplifier at a constant value despite fluctuations in said supply voltage.
Claim 6
Dependent Claim
15 words
The circuit arrangement of claim 6 wherein said means for maintaining is an additional diode.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |