BE558459A - - Google Patents
Info
- Publication number
- BE558459A BE558459A BE558459DA BE558459A BE 558459 A BE558459 A BE 558459A BE 558459D A BE558459D A BE 558459DA BE 558459 A BE558459 A BE 558459A
- Authority
- BE
- Belgium
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M19/00—Current supply arrangements for telephone systems
- H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
- H04M19/04—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone the ringing-current being generated at the substations
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Amplifiers (AREA)
- Devices For Supply Of Signal Current (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH3068325X | 1956-06-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE558459A true BE558459A (en:Method) |
Family
ID=4573865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE558459D BE558459A (en:Method) | 1956-06-19 |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US3068325A (en:Method) |
| BE (1) | BE558459A (en:Method) |
| CH (1) | CH342993A (en:Method) |
| DE (1) | DE1029040B (en:Method) |
| FR (1) | FR1176067A (en:Method) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3775562A (en) * | 1971-05-04 | 1973-11-27 | Data Transmission Sciences Inc | Security phone |
| US3908094A (en) * | 1971-12-15 | 1975-09-23 | Central Telephone S A | Telephone transceiver with amplified microphone and speaker |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2277623A (en) * | 1939-10-12 | 1942-03-24 | Bell Telephone Labor Inc | Telephone system |
| NL71904C (en:Method) * | 1947-06-14 | |||
| US2858371A (en) * | 1953-07-01 | 1958-10-28 | Gen Electric Co Ltd | Telephone subscribers' apparatus |
| GB743024A (en) * | 1953-07-01 | 1956-01-04 | Gen Electric Co Ltd | Improvements in or relating to telephone apparatus |
| BE563970A (en:Method) * | 1957-01-15 |
-
0
- BE BE558459D patent/BE558459A/xx unknown
-
1956
- 1956-06-19 CH CH342993D patent/CH342993A/de unknown
-
1957
- 1957-04-18 DE DEA26999A patent/DE1029040B/de active Pending
- 1957-06-10 US US664813A patent/US3068325A/en not_active Expired - Lifetime
- 1957-06-17 FR FR1176067D patent/FR1176067A/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE1029040B (de) | 1958-04-30 |
| US3068325A (en) | 1962-12-11 |
| FR1176067A (fr) | 1959-04-03 |
| CH342993A (de) | 1959-12-15 |