JPS56168469A - Transmitting system of alarm tone for permanent loop of telephone receiver - Google Patents

Transmitting system of alarm tone for permanent loop of telephone receiver

Info

Publication number
JPS56168469A
JPS56168469A JP7080880A JP7080880A JPS56168469A JP S56168469 A JPS56168469 A JP S56168469A JP 7080880 A JP7080880 A JP 7080880A JP 7080880 A JP7080880 A JP 7080880A JP S56168469 A JPS56168469 A JP S56168469A
Authority
JP
Japan
Prior art keywords
alarm tone
permanent loop
trunk
decoder
tone
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.)
Pending
Application number
JP7080880A
Other languages
Japanese (ja)
Inventor
Kiyoshi Shibuya
Masato Fujisawa
Kazuhiro Sato
Shoji Nojiri
Yoshikazu Tanaka
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.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP7080880A priority Critical patent/JPS56168469A/en
Publication of JPS56168469A publication Critical patent/JPS56168469A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/08—Indicating faults in circuits or apparatus
    • H04M3/14—Signalling existence of persistent "off-hook" condition

Landscapes

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

Abstract

PURPOSE:To eliminate a relay and at the same time simplify a control and adjustment, by applying the signal output of a sound source trunk to a delta modulation decoder to obtain an alarm tone for the permanent loop of the telephone. CONSTITUTION:When an alarm tone for a permanent loop of the telephone is transmitted, a decoder DELTAMDEC of the subscriber is connected to a signal tone trunk STT via a time-division switch TDSW. Then a number of ''1'' and ''0'' are applied to the decoder DELTAMDEC consecutively from the trunk STT to increase the output amplitude. This alarm tone is transmitted to a subscriber TEL via a hybrid circuit HYB and a subscriber line LL.
JP7080880A 1980-05-29 1980-05-29 Transmitting system of alarm tone for permanent loop of telephone receiver Pending JPS56168469A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7080880A JPS56168469A (en) 1980-05-29 1980-05-29 Transmitting system of alarm tone for permanent loop of telephone receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7080880A JPS56168469A (en) 1980-05-29 1980-05-29 Transmitting system of alarm tone for permanent loop of telephone receiver

Publications (1)

Publication Number Publication Date
JPS56168469A true JPS56168469A (en) 1981-12-24

Family

ID=13442228

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7080880A Pending JPS56168469A (en) 1980-05-29 1980-05-29 Transmitting system of alarm tone for permanent loop of telephone receiver

Country Status (1)

Country Link
JP (1) JPS56168469A (en)

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