JPS5474609A - Night changeover circuit - Google Patents

Night changeover circuit

Info

Publication number
JPS5474609A
JPS5474609A JP14164177A JP14164177A JPS5474609A JP S5474609 A JPS5474609 A JP S5474609A JP 14164177 A JP14164177 A JP 14164177A JP 14164177 A JP14164177 A JP 14164177A JP S5474609 A JPS5474609 A JP S5474609A
Authority
JP
Japan
Prior art keywords
terminal
main line
flowed
led
night
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
JP14164177A
Other languages
Japanese (ja)
Inventor
Shiro Enami
Kiichi Shimizu
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.)
Hitachi Ltd
Nippon Telegraph and Telephone Corp
Original Assignee
Hitachi Ltd
Nippon Telegraph and Telephone Corp
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 Hitachi Ltd, Nippon Telegraph and Telephone Corp filed Critical Hitachi Ltd
Priority to JP14164177A priority Critical patent/JPS5474609A/en
Publication of JPS5474609A publication Critical patent/JPS5474609A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/58—Arrangements providing connection between main exchange and sub-exchange or satellite
    • H04Q3/62—Arrangements providing connection between main exchange and sub-exchange or satellite for connecting to private branch exchanges
    • H04Q3/625—Arrangements in the private branch exchange

Landscapes

  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

PURPOSE:To make small the circuit in size by reducing the number and types of components through the use of photo couplers in PBX. CONSTITUTION:At night, when outgoing is made at the subscriber, the communication current is flowed in the path of the terminal 3,LED 11, terminal 1, main line, and terminals 1' and 3', turning on the photo transistor 12 and giving ground to the terminal 5. When the called party responses, the same current is flowed in LED 11 with the inversion of the polarity of the main line and ground is given to the terminal 5. Further, at the incoming from the main line, the call out signal is delivered to the subscriber via the bridge consisting of diodes 7 to 10.
JP14164177A 1977-11-28 1977-11-28 Night changeover circuit Pending JPS5474609A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14164177A JPS5474609A (en) 1977-11-28 1977-11-28 Night changeover circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14164177A JPS5474609A (en) 1977-11-28 1977-11-28 Night changeover circuit

Publications (1)

Publication Number Publication Date
JPS5474609A true JPS5474609A (en) 1979-06-14

Family

ID=15296762

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14164177A Pending JPS5474609A (en) 1977-11-28 1977-11-28 Night changeover circuit

Country Status (1)

Country Link
JP (1) JPS5474609A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57192191A (en) * 1981-05-20 1982-11-26 Fujitsu Ltd Night switching trunk circuit
JPS5812497A (en) * 1981-07-15 1983-01-24 Fujitsu Ltd Night switching trunk circuit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51100618A (en) * 1975-03-03 1976-09-06 Nippon Telegraph & Telephone Denwakokankiniokeru chokuryudenryukyokyuhoshiki
JPS5277617A (en) * 1975-12-24 1977-06-30 Nippon Telegr & Teleph Corp <Ntt> Pilot current supply unit in telephon exchange

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51100618A (en) * 1975-03-03 1976-09-06 Nippon Telegraph & Telephone Denwakokankiniokeru chokuryudenryukyokyuhoshiki
JPS5277617A (en) * 1975-12-24 1977-06-30 Nippon Telegr & Teleph Corp <Ntt> Pilot current supply unit in telephon exchange

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57192191A (en) * 1981-05-20 1982-11-26 Fujitsu Ltd Night switching trunk circuit
JPS5812497A (en) * 1981-07-15 1983-01-24 Fujitsu Ltd Night switching trunk circuit

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