US4053722A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state two-wire/four-wire converter with common battery
Assignee: United States Department of the Navy
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Filing: 1976-10-04
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Granted: 1977-10-11
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Expires: 1996-10-04
Abstract
Abstract A hybrid system utilizing a plurality of operational amplifiers provides for appropriate isolation of input and output signalling. A signal initially appearing at the incoming path of the four-wire line appears as a balanced signal at the two-wire input/output end of the system but is effectively canceled from appearing at the output path of the four-wire input/output end. A signal initially placed on the two wire input/output end of the system appears at the output of the four-wire input/output end but is effectively canceled from the input line of the four-wire input/output end. A direct current path for common battery supply of loop current, while maintaining line impedance match over the audio frequency bandwidth is maintained.
Inventors
- 👤 Lawrence P. Nahay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:34
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/54; H04B1/58; H04B1/586; H04M; H04M19/00; H04M19/001; H04M19/005
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
175 words
A two-wire/four-wire converter system comprising: four-wire input terminals, four-wire output terminals and a pair of two-wire input/output terminals; an inverting solid state constant current driver and a non-inverting solid state constant current driver, said drivers in combination connected to transmit and balance a signal from said four-wire input terminals to said two-wire input/output terminals; balancing means for use in inhibiting signals from said four-wire input terminals from appearing at said four-wire output terminals, said balancing means comprising a constant current amplifier having an input connected to said four-wire input terminals and a balancing network connected to the output of said constant current amplifier; amplifier means connected at its output to said four-wire output terminals, and connected at its input to said inverting constant current driver, said non-inverting constant current driver, said balancing means and said pair of two-wire input/output terminals for transmitting signals originating in the converter system at said two-wire input/output terminals and inhibiting signals originating in the converter system at said four-wire input terminals; and a battery connected to said two-wire input/output terminals.
Claim 2
Dependent Claim
175 words
A two-wire/four-wire converter system comprising: four-wire input terminals, four-wire output terminals and a pair of two-wire input/output terminals; an inverting solid state constant current driver and a non-inverting solid state constant current driver, said drivers in combination connected to transmit and balance a signal from said four-wire input terminals to said two-wire input/output terminals; balancing means for use in inhibiting signals from said four-wire input terminals from appearing at said four-wire output terminals, said balancing means comprising a constant current amplifier having an input connected to said four-wire input terminals and a balancing network connected to the output of said constant current amplifier; amplifier means connected at its output to said four-wire output terminals, and connected at its input to said inverting constant current driver, said non-inverting constant current driver, said balancing means and said pair of two-wire input/output terminals for transmitting signals originating in the converter system at said two-wire input/output terminals and inhibiting signals originating in the converter system at said four-wire input terminals; and a battery connected to said two-wire input/output terminals.
Claim 3
Dependent Claim
33 words
A two-wire/four-wire converter system according to claim 1 wherein each of said inverting solid state constant current driver, non-inverting solid state current driver, constant current amplifier and amplifier means comprises an operational 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) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |