JPS5745770A - Current supply circuit - Google Patents

Current supply circuit

Info

Publication number
JPS5745770A
JPS5745770A JP12111980A JP12111980A JPS5745770A JP S5745770 A JPS5745770 A JP S5745770A JP 12111980 A JP12111980 A JP 12111980A JP 12111980 A JP12111980 A JP 12111980A JP S5745770 A JPS5745770 A JP S5745770A
Authority
JP
Japan
Prior art keywords
terminal
grounding
supply circuit
resistor
current supply
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
JP12111980A
Other languages
Japanese (ja)
Inventor
Shiro Enami
Makoto Shinooka
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 JP12111980A priority Critical patent/JPS5745770A/en
Publication of JPS5745770A publication Critical patent/JPS5745770A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/001—Current supply source at the exchanger providing current to substations
    • H04M19/005—Feeding arrangements without the use of line transformers

Abstract

PURPOSE:To suppress the heating of the entire current supply circuit for grounding protection and to detect the grounding state, by operating the essential current supply circuit at looping only and operating another current supply circuit having higher internal resistance at grounding. CONSTITUTION:When a subscriber hooks off, a current flows with a path of ground, resistor R1, transistor TRQ1, terminal B, subscriber loop, terminal A, resistor R0, TRQ5, and battery -E. Thus, a TRQ2 is operated and the off-hook of a subscriber is displayed on a terminal SCN. If a ground failure is taken place at the terminal A, the base of a TRQ3 is pulled up to, e.g., +5V via resistors R7, R5, R4 and activated, then a current flows in the path of ground, terminal A, resistor R6 and TRQ5. When this grounding current reaches a prescribed amount or more, the potential at the terminal SCN split with the resistor R4 and the resistors R5+ R7 through the base current of the TRQ5 is negative to display the grounding of the terminal SCN.
JP12111980A 1980-09-03 1980-09-03 Current supply circuit Pending JPS5745770A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12111980A JPS5745770A (en) 1980-09-03 1980-09-03 Current supply circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12111980A JPS5745770A (en) 1980-09-03 1980-09-03 Current supply circuit

Publications (1)

Publication Number Publication Date
JPS5745770A true JPS5745770A (en) 1982-03-15

Family

ID=14803348

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12111980A Pending JPS5745770A (en) 1980-09-03 1980-09-03 Current supply circuit

Country Status (1)

Country Link
JP (1) JPS5745770A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54107609A (en) * 1978-02-13 1979-08-23 Hitachi Ltd Overcurrent automatic interruption system for telephone exchanger subscribing circuit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54107609A (en) * 1978-02-13 1979-08-23 Hitachi Ltd Overcurrent automatic interruption system for telephone exchanger subscribing circuit

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