NL54870C - - Google Patents
Info
- Publication number
- NL54870C NL54870C NL54870DA NL54870C NL 54870 C NL54870 C NL 54870C NL 54870D A NL54870D A NL 54870DA NL 54870 C NL54870 C NL 54870C
- 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
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/12—Modulator circuits; Transmitter circuits
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Relay Circuits (AREA)
- Transmitters (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEL95315D DE724392C (de) | 1938-07-30 | 1938-07-30 | Schaltungsanordnung zur Erzeugung von zwei im Takt einer dritten Frequenz abwechselnden Tonfrequenzen fuer die Tonfrequenzwahl in Fernsprechanlagen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL54870C true NL54870C (en:Method) |
Family
ID=7288086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL54870D NL54870C (en:Method) | 1938-07-30 |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US2285088A (en:Method) |
| BE (1) | BE435699A (en:Method) |
| CH (1) | CH212069A (en:Method) |
| DE (1) | DE724392C (en:Method) |
| FR (1) | FR858470A (en:Method) |
| NL (1) | NL54870C (en:Method) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2510531A (en) * | 1947-10-31 | 1950-06-06 | Rca Corp | Transmitter monitor |
-
0
- BE BE435699D patent/BE435699A/xx unknown
- NL NL54870D patent/NL54870C/xx active
-
1938
- 1938-07-30 DE DEL95315D patent/DE724392C/de not_active Expired
-
1939
- 1939-07-24 FR FR858470D patent/FR858470A/fr not_active Expired
- 1939-07-26 CH CH212069D patent/CH212069A/de unknown
- 1939-07-29 US US287197A patent/US2285088A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| FR858470A (fr) | 1940-11-26 |
| DE724392C (de) | 1942-08-25 |
| CH212069A (de) | 1940-10-31 |
| US2285088A (en) | 1942-06-02 |
| BE435699A (en:Method) |