BE447777A - - Google Patents
Info
- Publication number
- BE447777A BE447777A BE447777DA BE447777A BE 447777 A BE447777 A BE 447777A BE 447777D A BE447777D A BE 447777DA BE 447777 A BE447777 A BE 447777A
- Authority
- BE
- Belgium
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
- H04Q1/453—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling in which m-out-of-n signalling frequencies are transmitted
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q3/00—Selecting arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL256713X | 1941-11-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE447777A true BE447777A (US06521211-20030218-C00004.png) |
Family
ID=19781342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE447777D BE447777A (US06521211-20030218-C00004.png) | 1941-11-03 |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US2610255A (US06521211-20030218-C00004.png) |
| BE (1) | BE447777A (US06521211-20030218-C00004.png) |
| CH (1) | CH256713A (US06521211-20030218-C00004.png) |
| DE (1) | DE865475C (US06521211-20030218-C00004.png) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL225651A (US06521211-20030218-C00004.png) * | 1951-05-10 | |||
| US2885667A (en) * | 1955-07-06 | 1959-05-05 | Curtis L Downey | Display type communications system |
| US3209342A (en) * | 1960-05-23 | 1965-09-28 | Westinghouse Electric Corp | Apparatus for detecting and indicating alarm conditions in a protected area |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2057868A (en) * | 1936-10-20 | Telephone system | ||
| US2072079A (en) * | 1933-10-13 | 1937-03-02 | Gen Railway Signal Co | Centralized traffic controlling system for railroads |
| US2154776A (en) * | 1935-12-16 | 1939-04-18 | Ass Telephone & Telegraph Co | Telephone system |
| GB489545A (en) * | 1937-01-25 | 1938-07-25 | Standard Telephones Cables Ltd | Improvements in or relating to electrical communication systems |
| NL87334C (US06521211-20030218-C00004.png) * | 1938-10-03 | |||
| GB521419A (en) * | 1938-11-18 | 1940-05-21 | Siemens Brothers & Co Ltd | Improvements relating to telephone systems |
| US2341746A (en) * | 1940-04-15 | 1944-02-15 | Automatic Elect Lab | Telephone system |
| US2476343A (en) * | 1940-12-13 | 1949-07-19 | William W Wiseman | Frequency displacement |
| US2320081A (en) * | 1941-04-05 | 1943-05-25 | Bell Telephone Labor Inc | Telephone system |
| US2301961A (en) * | 1941-12-04 | 1942-11-17 | Bell Telephone Labor Inc | Signaling system |
| US2375053A (en) * | 1943-08-19 | 1945-05-01 | Bell Telephone Labor Inc | Signaling system |
| US2443198A (en) * | 1946-09-06 | 1948-06-15 | Max E Sallach | Pulse selector unit |
-
0
- BE BE447777D patent/BE447777A/xx unknown
-
1942
- 1942-11-03 CH CH256713D patent/CH256713A/de unknown
-
1947
- 1947-02-26 US US731136A patent/US2610255A/en not_active Expired - Lifetime
-
1950
- 1950-10-01 DE DEB10773A patent/DE865475C/de not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US2610255A (en) | 1952-09-09 |
| CH256713A (de) | 1948-08-31 |
| DE865475C (de) | 1953-02-02 |
