US3778563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voice frequency repeater
Assignee: Lear Siegler Inc
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Filing: 1972-03-29
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Granted: 1973-12-11
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Expires: 1992-03-29
Abstract
Abstract A repeater useful in 2-wire line telephone systems employs a pair of hybrid sets, each of which is rotated 90 degrees relative to the normal operation position. A relatively small hybrid set having a relatively low inductance has an inductor connected in the secondary, which has an inductance related to the inductance of the primary, to eliminate the need for the retard coils typically employed in the direct current line for repeaters, and also the need for isolation transformers. Consequently, the repeater is relatively economical and smaller in size. An attenuator employing L half-sections in the input of each amplifier provides direct reading gain and a bandpass amplifier in the input of each amplifier provides increased stability by eliminating the high and low frequencies outside the voice frequency band.
Inventors
- 👤 D Bise
- 👤 R Surprenant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:17
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/06; H01M10/12; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
353 words
A four-terminal voice frequency repeater for use in a twowire line comprising: a first transformer having a center-tapped amplifier winding and a pair of line windings; a second transformer having a center-tapped amplifier winding and a pair of line windings; one terminal of each line winding being connected to a separate terminal of the repeater, the second terminal of each line winding of the first transformer being connected together through a capacitor, the second terminal of each line winding of the second transformer being connected together through a capacitor; circuit means connecting the second terminal of one line winding of the first transformer to the second terminal of one line winding of the second transformer; circuit means connecting the second terminal of the other line winding of the first transformer to the second terminal of the other line winding of the second transformer; a first amplifier circuit being connected between one terminal of the amplifier winding of the first transformer and one terminal of the amplifier winding of the second transformer; a second amplifier circuit being connected between the other terminal of the amplifier winding of the first transformer and the other terminal of the amplifier winding of the second transformer; a first balancing network connected between the center tap of the amplifier winding of the first transformer and ground reference; and a second balancing network connected between the center tap of the amplifier winding of the second transformer and ground reference, each amplifier circuit including an attenuator network connected between the terminal of the amplifier winding and the input of the active element of the amplifier circuit, with the attenuator network comprising: a plurality of resistors connected in series between the terminal of the line winding and the input to the active element of the amplifier circuit, a plurality of shunt resistors with a shunt resistor connected between each junction between two series resistors and ground reference and a shunt resistor connected between the input to the active element and ground reference, individual switch means connected across each series resistor, and individual switch means connected between each shunt resistor and ground reference.
Claim 2
Dependent Claim
353 words
A four-terminal voice frequency repeater for use in a twowire line comprising: a first transformer having a center-tapped amplifier winding and a pair of line windings; a second transformer having a center-tapped amplifier winding and a pair of line windings; one terminal of each line winding being connected to a separate terminal of the repeater, the second terminal of each line winding of the first transformer being connected together through a capacitor, the second terminal of each line winding of the second transformer being connected together through a capacitor; circuit means connecting the second terminal of one line winding of the first transformer to the second terminal of one line winding of the second transformer; circuit means connecting the second terminal of the other line winding of the first transformer to the second terminal of the other line winding of the second transformer; a first amplifier circuit being connected between one terminal of the amplifier winding of the first transformer and one terminal of the amplifier winding of the second transformer; a second amplifier circuit being connected between the other terminal of the amplifier winding of the first transformer and the other terminal of the amplifier winding of the second transformer; a first balancing network connected between the center tap of the amplifier winding of the first transformer and ground reference; and a second balancing network connected between the center tap of the amplifier winding of the second transformer and ground reference, each amplifier circuit including an attenuator network connected between the terminal of the amplifier winding and the input of the active element of the amplifier circuit, with the attenuator network comprising: a plurality of resistors connected in series between the terminal of the line winding and the input to the active element of the amplifier circuit, a plurality of shunt resistors with a shunt resistor connected between each junction between two series resistors and ground reference and a shunt resistor connected between the input to the active element and ground reference, individual switch means connected across each series resistor, and individual switch means connected between each shunt resistor and ground reference.
Claim 3
Dependent Claim
27 words
A voice frequency repeater in accordance with claim 1 wherein the removal of each L half-section causes a preselected increase in the gain of the amplifier circuit.
Claim 4
Dependent Claim
39 words
A voice frequency repeater in accordance with claim 1 wherein the switch means for each L half-section in the first amplifier circuit is mechanically coupled to the switch means in the corresponding L half-sections of the second amplifier circuit.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |