GB243188A - Improvements in or relating to telephone systems - Google Patents
Improvements in or relating to telephone systemsInfo
- Publication number
- GB243188A GB243188A GB27725A GB27725A GB243188A GB 243188 A GB243188 A GB 243188A GB 27725 A GB27725 A GB 27725A GB 27725 A GB27725 A GB 27725A GB 243188 A GB243188 A GB 243188A
- Authority
- GB
- United Kingdom
- Prior art keywords
- switch
- numerical
- circuit
- switches
- relay
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Monitoring And Testing Of Exchanges (AREA)
Abstract
243,188. Coventry Automatic Telephones, Ltd., and collyer, J. E. Jan. 5, 1925. A u t o m a t i c exchange systems.-In a system in which automatic switches such as numerical selectors have access over intermediate non-numerical switches to outgoing trunks, only that non-numerical switch which is next available to a particular selector is caused to preselect an idle trunk. Such a switch on being taken into use closes a circuit for causing the next available switch to preselect. Alternatively, to take care of practically simultaneous connections, the next two or more. non-numerical switches may be caused to preselect. The switch shown is accessible from a particular level of a Strowger group selector and when the preceding switch accessible on that level is taken into use the switching relay 51 thereof completes a circuit for relay 3 which connects stepping magnet 5 to the test wiper 8 so that the switch hunts until an idle two-wire inter-exchange trunk 14, 13 is reached. When this switch is subsequently seized by a group selector, earth on the release conductor 22 operates switching relay 1 which extends the connection to the preselected trunk 14, 13 and at armature 2 completes a preselecting circuit for the next available non- numerical switch. Different shelves of group selectors have different first-choice non-numerical switches but corresponding levels of all the selectors on a particular shelf have the same non- numerical switch as first-choice and the preselecting circuit for this switch is closed over a conductor 53 by a shelf relay operated when a switch on that shelf is taken into use or is raised to the appropriate level. When all the trunks accessible to a particular switch are busy, relays 101 complete a chain circuit for relay 104 which opens the preselecting circuit, connects earth over the circuit 105, 102, 11, 21 to mark all idle switches non-selectable, by the group selectors, and may also operate a meter. The invention mav be applied to system in which grading of trunks is employed, and the switches may also be provided with means for automatically freeing themselves from a faulty trunk.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB27725A GB243188A (en) | 1925-01-05 | 1925-01-05 | Improvements in or relating to telephone systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB27725A GB243188A (en) | 1925-01-05 | 1925-01-05 | Improvements in or relating to telephone systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB243188A true GB243188A (en) | 1925-11-26 |
Family
ID=9701518
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB27725A Expired GB243188A (en) | 1925-01-05 | 1925-01-05 | Improvements in or relating to telephone systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB243188A (en) |
-
1925
- 1925-01-05 GB GB27725A patent/GB243188A/en not_active Expired
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