GB634076A - Improvements in arrangements for disconnecting false calls in automatic telephone systems - Google Patents
Improvements in arrangements for disconnecting false calls in automatic telephone systemsInfo
- Publication number
- GB634076A GB634076A GB28102/45A GB2810245A GB634076A GB 634076 A GB634076 A GB 634076A GB 28102/45 A GB28102/45 A GB 28102/45A GB 2810245 A GB2810245 A GB 2810245A GB 634076 A GB634076 A GB 634076A
- Authority
- GB
- United Kingdom
- Prior art keywords
- line
- operates
- magnet
- selecting
- register
- 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
- H04Q—SELECTING
- H04Q3/00—Selecting arrangements
- H04Q3/0004—Selecting arrangements using crossbar selectors in the switching stages
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Monitoring And Testing Of Exchanges (AREA)
Abstract
634,076. Automatic exchange systems. TELEFONAKTIEBOLAGET L. M. ERICSSON. Oct. 24, 1945, No. 28102. Convention date, Nov. 10, 1944. [Class 40 (iv)] To prevent a faulty line from holding up exchange apparatus, a time control is arranged to connect the line to dead terminals in a crossbar preselector switch if calling digits are not transmitted within a fixed period. As shown, an operating bar allotted to a line La, Lb is controlled by a magnet BM. Selecting magnets SM1 to SM9 control the connection of the line over one of several links to a register (not shown). Each link comprises five wires a ... e. Magnet SMO controls the connection to dead terminals. Normal call. A line relay LR operates in the usual manner and applies potential to wires m<SP>3</SP>, m<SP>4</SP> to identify the calling line in a marker and to start a selecting operation. The marker selects a link, operates a selecting magnet, say SM9, and applies a momentary potential to wire m<SP>5</SP> when the operation of SM9 is signalled back over ml. Magnet BM operates and is held by a potential on the line c. The marker is released and the call is completed with the help of the register. Faulty line. If no selecting digits are received by the register, a time control causes the register to cut off the holding potential for BM in wire c and to seize the marker which operates the selecting magnet SM0. The switch operates as before. Relay LR releases when BM operates and BM is held over contact 2, line La, Lb, contact 1 and, if desired, over a buzzer signal transformer Sui. When the line loop is broken, the equipment returns to normal. Any outgoing call meeting a busy condition may be transferred to the dead terminal position controlled by the magnet SM0. A metering device is shown at SM.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE634076X | 1944-11-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB634076A true GB634076A (en) | 1950-03-15 |
Family
ID=20313598
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB28102/45A Expired GB634076A (en) | 1944-11-10 | 1945-10-24 | Improvements in arrangements for disconnecting false calls in automatic telephone systems |
Country Status (2)
| Country | Link |
|---|---|
| FR (1) | FR914757A (en) |
| GB (1) | GB634076A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110247759B (en) * | 2019-06-03 | 2020-07-10 | 武汉理工大学 | SM9 private key generation and use method and system |
-
1945
- 1945-09-24 FR FR914757D patent/FR914757A/en not_active Expired
- 1945-10-24 GB GB28102/45A patent/GB634076A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR914757A (en) | 1946-10-17 |
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