US4035586A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current supply system for terminal devices
Assignee: Hitachi Ltd
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Filing: 1976-02-24
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Granted: 1977-07-12
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Expires: 1996-02-24
Abstract
Abstract A current supply system for terminal devices in which the line circuits are divided into groups in accordance with the line impedance thereof between an exchange or switching network and respective terminal devices or telephone sets, and a different voltage is applied to respective groups of line circuits which corresponds to the current matching the line impedance for the respective groups of line circuits.
Inventors
- 👤 Hirotoshi Shirasu
- 👤 Hidetaka Yamashita
- 👤 Tatsumasa Oonuma
- 👤 Takeshi Fukuhara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:01
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/001
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
95 words
A current supply system for terminal devices comprising a plurality of line circuits each connected to a separate terminal device through a separated line, said line circuits being divided into a plurality of line circuit groups in accordance with the line impedance connected to the line circuit, a plurality of separate power sources of different voltage value associated with the line circuit groups in accordance with the impedance thereof, and means for connecting each one of the line circuits included in each respective line circuit group in common to the respective power source associated therewith.
Claim 2
Dependent Claim
95 words
A current supply system for terminal devices comprising a plurality of line circuits each connected to a separate terminal device through a separated line, said line circuits being divided into a plurality of line circuit groups in accordance with the line impedance connected to the line circuit, a plurality of separate power sources of different voltage value associated with the line circuit groups in accordance with the impedance thereof, and means for connecting each one of the line circuits included in each respective line circuit group in common to the respective power source associated therewith.
Claim 3
Dependent Claim
16 words
A current supply system according to claim 1, wherein the terminal device comprises a telephone set.
Claim 4
Dependent Claim
22 words
A current supply system according to claim 2, wherein the line circuit comprises a transformer whose winding is connected to the line.
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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |