GB684531A - Improvements in or relating to telephone systems - Google Patents

Improvements in or relating to telephone systems

Info

Publication number
GB684531A
GB684531A GB1208/51A GB120851A GB684531A GB 684531 A GB684531 A GB 684531A GB 1208/51 A GB1208/51 A GB 1208/51A GB 120851 A GB120851 A GB 120851A GB 684531 A GB684531 A GB 684531A
Authority
GB
United Kingdom
Prior art keywords
tube
line
wires
fires
tubes
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
Application number
GB1208/51A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Publication of GB684531A publication Critical patent/GB684531A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

684,531. Automatic exchange systems. TELEFONAKTIEBOLAGET L. M. ERICSSON. Jan. 16, 1951 [Jan. 16, 1950], No. 1208/51. Class 40 (iv). In an arrangement in which subscribers' line wires are connected over high resistances r1, r2 to different potentials, the change of potential on the b wire when a call is made fires the corresponding one of a set of discharge tubes GR which are connected over a common resistance r4 to battery, and the change of potential at the junction-point fires a tube G and thereby energizes a group relay R which extends the b wires to a marker M. Line finders S operate under the control of the marker M, and when feed battery is connected to the calling line the tube GR is shunted out and the subscriber receives dialling tone. Another set of tubes GL are connected between the band c wires, and in the event of a busy condition a negative impulse on the c wire fires the corresponding tube and allows busy tone to pass from a transformer T. Similar action occurs if no dialling impulses are received, and the glowing of the tube GL indicates the defective line. The pairs of tubes GR, GL may be combined in the same envelopes.
GB1208/51A 1950-01-16 1951-01-16 Improvements in or relating to telephone systems Expired GB684531A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE684531X 1950-01-16

Publications (1)

Publication Number Publication Date
GB684531A true GB684531A (en) 1952-12-17

Family

ID=20315016

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1208/51A Expired GB684531A (en) 1950-01-16 1951-01-16 Improvements in or relating to telephone systems

Country Status (4)

Country Link
BE (1) BE500623A (en)
DE (1) DE853301C (en)
FR (1) FR1031047A (en)
GB (1) GB684531A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE545100A (en) * 1953-07-03
DE1029422B (en) * 1955-09-30 1958-05-08 Siemens Ag Relayless subscriber circuit for telecommunication, especially telephone systems

Also Published As

Publication number Publication date
BE500623A (en)
FR1031047A (en) 1953-06-18
DE853301C (en) 1952-10-23

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