NL72721C - - Google Patents
Info
- Publication number
- NL72721C NL72721C NL72721DA NL72721C NL 72721 C NL72721 C NL 72721C NL 72721D A NL72721D A NL 72721DA NL 72721 C NL72721 C NL 72721C
- Authority
- NL
- Netherlands
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/40—Applications of speech amplifiers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/60—Semi-automatic systems, i.e. in which the numerical selection of the outgoing line is under the control of an operator
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q3/00—Selecting arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q3/00—Selecting arrangements
- H04Q3/42—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Interface Circuits In Exchanges (AREA)
- Sub-Exchange Stations And Push- Button Telephones (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US243347A US2208765A (en) | 1938-12-01 | 1938-12-01 | Telephone system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL72721C true NL72721C (zh) |
Family
ID=22918388
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL72721D NL72721C (zh) | 1938-12-01 | ||
| NL70515D NL70515C (zh) | 1938-12-01 |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL70515D NL70515C (zh) | 1938-12-01 |
Country Status (6)
| Country | Link |
|---|---|
| US (3) | US2208765A (zh) |
| BE (1) | BE476596A (zh) |
| CH (2) | CH286287A (zh) |
| FR (2) | FR951758A (zh) |
| GB (2) | GB640033A (zh) |
| NL (2) | NL70515C (zh) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2586901A (en) * | 1948-07-24 | 1952-02-26 | Bell Telephone Labor Inc | Two-way trunk circuit arranged for dial-back operations |
| US2691068A (en) * | 1950-12-11 | 1954-10-05 | Stromberg Carlson Co | Two-way carrier type trunk circuit |
| US2715158A (en) * | 1951-10-31 | 1955-08-09 | Stromberg Carlson Co | Signaling system |
| US2708692A (en) * | 1952-06-14 | 1955-05-17 | Automatic Elect Lab | Toll switching telephone systems |
| US2726285A (en) * | 1952-09-06 | 1955-12-06 | Gen Dynamics Corp | Dial cord circuit |
| US2769862A (en) * | 1953-02-06 | 1956-11-06 | Gen Dynamics Corp | Convertible interoffice trunk |
-
0
- NL NL72721D patent/NL72721C/xx active
- NL NL70515D patent/NL70515C/xx active
- BE BE476596D patent/BE476596A/xx unknown
- US US22441D patent/USRE22441E/en not_active Expired
- US US22440D patent/USRE22440E/en not_active Expired
-
1938
- 1938-12-01 US US243347A patent/US2208765A/en not_active Expired - Lifetime
-
1947
- 1947-08-07 FR FR951758D patent/FR951758A/fr not_active Expired
- 1947-08-07 FR FR1031552D patent/FR1031552A/fr not_active Expired
- 1947-08-07 GB GB21771/47A patent/GB640033A/en not_active Expired
- 1947-08-07 GB GB21770/47A patent/GB640032A/en not_active Expired
- 1947-08-08 CH CH286287D patent/CH286287A/fr unknown
- 1947-08-08 CH CH276283D patent/CH276283A/fr unknown
Also Published As
| Publication number | Publication date |
|---|---|
| CH276283A (fr) | 1951-06-30 |
| CH286287A (fr) | 1952-10-15 |
| USRE22440E (en) | 1944-02-22 |
| GB640032A (en) | 1950-07-12 |
| NL70515C (zh) | |
| FR951758A (fr) | 1949-11-03 |
| USRE22441E (en) | 1944-02-22 |
| BE476596A (zh) | |
| US2208765A (en) | 1940-07-23 |
| GB640033A (en) | 1950-07-12 |
| FR1031552A (fr) | 1953-06-24 |