US3959718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current supply source
Assignee: Oki Electric Industry Co Ltd
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Filing: 1974-06-03
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Granted: 1976-05-25
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Expires: 1994-06-03
Abstract
Abstract A direct current supply circuit for supplying a direct current to a communication terminal device as well as for repeating information from said communication terminal device to an electronic exchange has been disclosed. Said direct current supply circuit comprises a transformer, which has four primary windings. By arranging the direction of the direct current in said primary windings, saturation of magnetic flux in said transformer can be prevented and thus, the size of the transformer can be reduced.
Inventors
- 👤 Kiyoshi Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:50
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/001; H04M19/003
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
158 words
A method for supplying a direct current from a current source through a transformer having four primary windings and a transmission line to a communication terminal device comprising the steps of; a. flowing a direct current in a circuit from one end of the current source through the beginning of a second primary winding, the end of the second primary winding, the end of the first primary winding, the beginning of the first primary winding, the transmission line, the communication terminal device, the transmission line, the end of the fourth primary winding, the beginning of the fourth primary winding, the beginning of the third primary winding, and the end of the third winding, to the other end of the current source, b. transmitting an alternate current from the communication terminal device through the transmission line, first and fourth primary windings connected by a capacitor to each other, and a secondary winding of said transformer, to an electronic exchange.
Claim 2
Independent Claim
158 words
A method for supplying a direct current from a current source through a transformer having four primary windings and a transmission line to a communication terminal device comprising the steps of; a. flowing a direct current in a circuit from one end of the current source through the beginning of a second primary winding, the end of the second primary winding, the end of the first primary winding, the beginning of the first primary winding, the transmission line, the communication terminal device, the transmission line, the end of the fourth primary winding, the beginning of the fourth primary winding, the beginning of the third primary winding, and the end of the third winding, to the other end of the current source, b. transmitting an alternate current from the communication terminal device through the transmission line, first and fourth primary windings connected by a capacitor to each other, and a secondary winding of said transformer, to an electronic exchange.
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) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |