NL56981C - - Google Patents
Info
- Publication number
- NL56981C NL56981C NL56981DA NL56981C NL 56981 C NL56981 C NL 56981C NL 56981D A NL56981D A NL 56981DA NL 56981 C NL56981 C NL 56981C
- Authority
- NL
- Netherlands
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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Interface Circuits In Exchanges (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEL95305A DE761755C (de) | 1938-07-30 | 1938-07-30 | Schaltungsanordnung fuer Fernmeldeanlagen, in denen Signale durch Wechselstroeme einer bestimmten Frequenz gegeben werden |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL56981C true NL56981C (da) |
Family
ID=27797494
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL55006D NL55006C (da) | 1938-07-30 | ||
| NL56981D NL56981C (da) | 1938-07-30 |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL55006D NL55006C (da) | 1938-07-30 |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US2238263A (da) |
| BE (1) | BE435700A (da) |
| CH (1) | CH213513A (da) |
| DE (1) | DE761755C (da) |
| FR (1) | FR858471A (da) |
| NL (2) | NL56981C (da) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE428639C (de) * | 1926-05-20 | Siemens & Halske Akt Ges | Elektrische Anrufeinrichtung fuer Fernmeldeleitungen | |
| DE377922C (de) * | 1921-02-22 | 1923-06-29 | Western Electric Co Ltd | Schaltungsanordnung zur Signaluebermittlung |
-
0
- BE BE435700D patent/BE435700A/xx unknown
- NL NL55006D patent/NL55006C/xx active
- NL NL56981D patent/NL56981C/xx active
-
1938
- 1938-07-30 DE DEL95305A patent/DE761755C/de not_active Expired
-
1939
- 1939-07-22 US US285863A patent/US2238263A/en not_active Expired - Lifetime
- 1939-07-26 CH CH213513D patent/CH213513A/de unknown
- 1939-07-28 FR FR858471D patent/FR858471A/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CH213513A (de) | 1941-02-15 |
| FR858471A (fr) | 1940-11-26 |
| BE435700A (da) | |
| US2238263A (en) | 1941-04-15 |
| NL55006C (da) | |
| DE761755C (de) | 1953-11-02 |