FR713494A - Improvements to switching devices for telephone systems - Google Patents
Improvements to switching devices for telephone systemsInfo
- Publication number
- FR713494A FR713494A FR713494DA FR713494A FR 713494 A FR713494 A FR 713494A FR 713494D A FR713494D A FR 713494DA FR 713494 A FR713494 A FR 713494A
- Authority
- FR
- France
- Prior art keywords
- switching devices
- telephone systems
- telephone
- systems
- switching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M17/00—Prepayment of wireline communication systems, wireless communication systems or telephone systems
- H04M17/02—Coin-freed or check-freed systems, e.g. mobile- or card-operated phones, public telephones or booths
- H04M17/023—Circuit arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Computer Security & Cryptography (AREA)
- Signal Processing (AREA)
- Interface Circuits In Exchanges (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE355181X | 1930-03-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
FR713494A true FR713494A (en) | 1931-10-28 |
Family
ID=20308758
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR713494D Expired FR713494A (en) | 1930-03-21 | 1931-03-18 | Improvements to switching devices for telephone systems |
Country Status (6)
Country | Link |
---|---|
US (1) | US1855087A (en) |
BE (1) | BE378410A (en) |
DE (1) | DE583068C (en) |
FR (1) | FR713494A (en) |
GB (1) | GB355181A (en) |
NL (1) | NL34614C (en) |
-
0
- NL NL34614D patent/NL34614C/xx active
- BE BE378410D patent/BE378410A/xx unknown
-
1931
- 1931-03-13 US US522461A patent/US1855087A/en not_active Expired - Lifetime
- 1931-03-18 FR FR713494D patent/FR713494A/en not_active Expired
- 1931-03-19 GB GB8512/31A patent/GB355181A/en not_active Expired
- 1931-03-19 DE DET38565D patent/DE583068C/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
NL34614C (en) | |
US1855087A (en) | 1932-04-19 |
GB355181A (en) | 1931-08-20 |
BE378410A (en) | |
DE583068C (en) | 1933-08-28 |
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