JPS57206151A - Line circuit trunk of telephone exchange - Google Patents

Line circuit trunk of telephone exchange

Info

Publication number
JPS57206151A
JPS57206151A JP9181181A JP9181181A JPS57206151A JP S57206151 A JPS57206151 A JP S57206151A JP 9181181 A JP9181181 A JP 9181181A JP 9181181 A JP9181181 A JP 9181181A JP S57206151 A JPS57206151 A JP S57206151A
Authority
JP
Japan
Prior art keywords
relay
telephone
call signal
works
line circuit
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.)
Granted
Application number
JP9181181A
Other languages
Japanese (ja)
Other versions
JPS6332307B2 (en
Inventor
Katsuaki Fuji
Mitsuo Aoki
Yuji Hamada
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 JP9181181A priority Critical patent/JPS57206151A/en
Publication of JPS57206151A publication Critical patent/JPS57206151A/en
Publication of JPS6332307B2 publication Critical patent/JPS6332307B2/ja
Granted 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

PURPOSE:To detect quickly the off-hook of a telephone and to eliminate the occurrence of the noise to a subscriber circuit, by using a receiving relay of the call signal for a line circuit trunk. CONSTITUTION:The call signal is applied at all times to a line circuit trunk. A receiving relay R works only while the call signal exists. With the actuation of the relay R, the contacts r1 and r2 work to transmit the call signal directly to a telephone. If the telephone is hooked off at this moment, a ring trip relay RT works. When the actuation of the relay RT is detected, the relay R is restored. Thus a relay J works with the off-hook state of the telephone, i.e., a loop at the telephone side. Accordingly a relay B also works. Under such conditions, a call is possible. As the off-hook can be immediately detected and the call signal is simultaneously stopped, no unpleasant sound is given to the telephone of subscriber being called.
JP9181181A 1981-06-15 1981-06-15 Line circuit trunk of telephone exchange Granted JPS57206151A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9181181A JPS57206151A (en) 1981-06-15 1981-06-15 Line circuit trunk of telephone exchange

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9181181A JPS57206151A (en) 1981-06-15 1981-06-15 Line circuit trunk of telephone exchange

Publications (2)

Publication Number Publication Date
JPS57206151A true JPS57206151A (en) 1982-12-17
JPS6332307B2 JPS6332307B2 (en) 1988-06-29

Family

ID=14037007

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9181181A Granted JPS57206151A (en) 1981-06-15 1981-06-15 Line circuit trunk of telephone exchange

Country Status (1)

Country Link
JP (1) JPS57206151A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55104163A (en) * 1979-02-02 1980-08-09 Hitachi Ltd Transmission circuit for callout signal

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55104163A (en) * 1979-02-02 1980-08-09 Hitachi Ltd Transmission circuit for callout signal

Also Published As

Publication number Publication date
JPS6332307B2 (en) 1988-06-29

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