JPS5710635B2 - - Google Patents
Info
- Publication number
- JPS5710635B2 JPS5710635B2 JP4378A JP4378A JPS5710635B2 JP S5710635 B2 JPS5710635 B2 JP S5710635B2 JP 4378 A JP4378 A JP 4378A JP 4378 A JP4378 A JP 4378A JP S5710635 B2 JPS5710635 B2 JP S5710635B2
- Authority
- JP
- Japan
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M19/00—Current supply arrangements for telephone systems
- H04M19/001—Current supply source at the exchanger providing current to substations
- H04M19/008—Using DC/DC converters
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Interface Circuits In Exchanges (AREA)
- Devices For Supply Of Signal Current (AREA)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP437879A JPS5596439A (en) | 1978-01-05 | 1979-01-17 | Areometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/757,006 US4056691A (en) | 1977-01-05 | 1977-01-05 | Telephone subscriber line circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5387109A JPS5387109A (en) | 1978-08-01 |
| JPS5710635B2 true JPS5710635B2 (US06633600-20031014-M00021.png) | 1982-02-27 |
Family
ID=25045972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4378A Granted JPS5387109A (en) | 1977-01-05 | 1978-01-05 | Telephone line interface circuit |
Country Status (12)
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4142075A (en) * | 1977-10-11 | 1979-02-27 | Burr-Brown Research Corporation | Interface circuit and method for telephone extension lines |
| NL7807706A (nl) * | 1978-07-19 | 1980-01-22 | Philips Nv | Voedingsbrug met d.c.-compensatie voor beide richtin- gen van de voedingstroom. |
| US4254305A (en) * | 1979-02-07 | 1981-03-03 | International Telephone And Telegraph Corporation | Current limited subscriber line feed circuit |
| US4243842A (en) * | 1979-04-24 | 1981-01-06 | Northern Telecom Limited | Telephone line circuit |
| DE2938981A1 (de) * | 1979-09-26 | 1981-04-30 | Siemens AG, 1000 Berlin und 8000 München | Schaltungsanordnung zur registrierung des schaltzustandes in einem insbesondere durch teilnehmeranschlussleitungen von fernsprechvermittlungsanlagen gebildeten schaltkreis |
| US4315106A (en) * | 1979-11-28 | 1982-02-09 | International Telephone And Telegraph Corporation | Apparatus for regulating current supplied to a telephone line signal of the type employed in digital telephone systems |
| US4323734A (en) * | 1980-05-15 | 1982-04-06 | Crest Industries, Inc. | Interface circuit for telephone line to equipment signal coupling |
| US4423292A (en) * | 1981-09-30 | 1983-12-27 | Bell Telephone Laboratories, Incorporated | Detector circuit for communication lines |
| US4458112A (en) * | 1981-10-29 | 1984-07-03 | Telefonaktiebolaget L M Ericsson | Floating subscriber loop interface circuit |
| US4552994A (en) * | 1982-12-13 | 1985-11-12 | Gte Lenkurt Incorporated Communication Systems | Apparatus for isolating the voice frequency path from the floating battery feed during signalling |
| US4499532A (en) * | 1983-03-23 | 1985-02-12 | At&T Bell Laboratories | Floating battery feed circuit |
| US4551670A (en) * | 1984-04-19 | 1985-11-05 | At&T Bell Laboratories | Circuit for maintaining the DC voltage on an electrically isolated telecommunication line at a reference level |
| US4679232A (en) * | 1985-08-02 | 1987-07-07 | American Telephone And Telegraph Company, At&T Bell Laboratories | Method and apparatus for providing a ground reference for telephone customer special circuits powered from a floating battery feed |
| US4704670A (en) * | 1986-12-31 | 1987-11-03 | American Telephone & Telegraph Company, At&T Bell Laboratories | Power supply with regulated output voltage |
| US6819761B1 (en) * | 1999-09-16 | 2004-11-16 | Silicon Laboratories, Inc. | Programmable constant current “off hook” circuit |
| US11448670B2 (en) * | 2020-12-23 | 2022-09-20 | Hamilton Sundstrand Corporation | Overcurrent detection using dissimilar biasing of diode networks |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3522384A (en) * | 1968-01-16 | 1970-07-28 | Tri State Communication Servic | Constant current operation of central office telephone equipment |
| US3546564A (en) * | 1968-11-25 | 1970-12-08 | Us Air Force | Stabilized constant current apparatus |
| US3914556A (en) * | 1974-06-12 | 1975-10-21 | Itt | On-hook and off-hook detector for telephone switching systems |
| US3955052A (en) * | 1974-11-18 | 1976-05-04 | Tadiran Israel Electronics Industries Ltd. | Subscriber unit particularly useful for time-division-multiplex system |
| US4027235A (en) * | 1976-08-13 | 1977-05-31 | Gte Automatic Electric Laboratories Incorporated | Direct current compensation circuit with current threshold detection |
-
1977
- 1977-01-05 US US05/757,006 patent/US4056691A/en not_active Expired - Lifetime
- 1977-11-23 CA CA291,542A patent/CA1089133A/en not_active Expired
- 1977-12-27 SE SE7714791A patent/SE421851B/sv not_active IP Right Cessation
- 1977-12-30 FR FR7739856A patent/FR2377133A1/fr active Granted
- 1977-12-30 IT IT69983/77A patent/IT1091649B/it active
- 1977-12-30 NL NL7714596A patent/NL7714596A/xx not_active Application Discontinuation
- 1977-12-30 BE BE184004A patent/BE862521A/xx not_active IP Right Cessation
-
1978
- 1978-01-03 DE DE2800158A patent/DE2800158C3/de not_active Expired
- 1978-01-04 CH CH9778A patent/CH625656A5/de not_active IP Right Cessation
- 1978-01-04 GB GB163/78A patent/GB1591073A/en not_active Expired
- 1978-01-05 JP JP4378A patent/JPS5387109A/ja active Granted
- 1978-01-05 ES ES465797A patent/ES465797A1/es not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NL7714596A (nl) | 1978-07-07 |
| FR2377133A1 (fr) | 1978-08-04 |
| ES465797A1 (es) | 1978-09-16 |
| SE421851B (sv) | 1982-02-01 |
| IT1091649B (it) | 1985-07-06 |
| BE862521A (fr) | 1978-04-14 |
| GB1591073A (en) | 1981-06-10 |
| JPS5387109A (en) | 1978-08-01 |
| CH625656A5 (US06633600-20031014-M00021.png) | 1981-09-30 |
| CA1089133A (en) | 1980-11-04 |
| SE7714791L (sv) | 1978-07-06 |
| DE2800158A1 (de) | 1978-07-13 |
| DE2800158B2 (de) | 1980-08-14 |
| US4056691A (en) | 1977-11-01 |
| FR2377133B1 (US06633600-20031014-M00021.png) | 1980-08-22 |
| DE2800158C3 (de) | 1981-06-25 |
