GB988024A - Improvements in or relating to electronic telephone exchanges - Google Patents

Improvements in or relating to electronic telephone exchanges

Info

Publication number
GB988024A
GB988024A GB40763A GB40763A GB988024A GB 988024 A GB988024 A GB 988024A GB 40763 A GB40763 A GB 40763A GB 40763 A GB40763 A GB 40763A GB 988024 A GB988024 A GB 988024A
Authority
GB
United Kingdom
Prior art keywords
exchange
wires
test
mrb
mra
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
GB40763A
Inventor
Thomas Harold Flowers
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.)
Post Office
Original Assignee
Post Office
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 Post Office filed Critical Post Office
Priority to GB40763A priority Critical patent/GB988024A/en
Publication of GB988024A publication Critical patent/GB988024A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/22—Arrangements for supervision, monitoring or testing
    • H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
    • H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

988,024. Automatic exchange systems. POSTMASTER GENERAL. Jan. 3, 1964 [Jan. 3, 1963], No. 407/63. Heading H4K. In order to test exchange lines each of the wires L1, L2 of each line has a semi-conductor device MRA, MRB, which normally present low impedance to loop current from the exchange battery B1, connections between the wires L1, L2, and a test desk TD being set up over switches S so that on operation of test keys DS the devices MRA, MRB, are biased to high impedance by batteries B2, B3, to isolate the wires from the exchange. As shown, the semi-conductor devices are silicon rectifiers but they may be provided by the emitter-collector paths of transistors.
GB40763A 1963-01-03 1963-01-03 Improvements in or relating to electronic telephone exchanges Expired GB988024A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB40763A GB988024A (en) 1963-01-03 1963-01-03 Improvements in or relating to electronic telephone exchanges

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB40763A GB988024A (en) 1963-01-03 1963-01-03 Improvements in or relating to electronic telephone exchanges

Publications (1)

Publication Number Publication Date
GB988024A true GB988024A (en) 1965-03-31

Family

ID=9703842

Family Applications (1)

Application Number Title Priority Date Filing Date
GB40763A Expired GB988024A (en) 1963-01-03 1963-01-03 Improvements in or relating to electronic telephone exchanges

Country Status (1)

Country Link
GB (1) GB988024A (en)

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