JPS54151309A - Supply circuit for communication current - Google Patents

Supply circuit for communication current

Info

Publication number
JPS54151309A
JPS54151309A JP6026078A JP6026078A JPS54151309A JP S54151309 A JPS54151309 A JP S54151309A JP 6026078 A JP6026078 A JP 6026078A JP 6026078 A JP6026078 A JP 6026078A JP S54151309 A JPS54151309 A JP S54151309A
Authority
JP
Japan
Prior art keywords
terminals
impedance
differential
signal
supply 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.)
Pending
Application number
JP6026078A
Other languages
Japanese (ja)
Inventor
Koichi Hasegawa
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co 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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP6026078A priority Critical patent/JPS54151309A/en
Publication of JPS54151309A publication Critical patent/JPS54151309A/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

Abstract

PURPOSE:To increase the differential AC impedance of the communication path and to avoid attenuation of the communication signal, by providing a pair of differential input operational amplifiers and low pass filter with the communication current supply circuit. CONSTITUTION:A pair of telephone lines are connected between the terminals 1 and 2, and constant current and voltage is fed via the transistors 9 and 10 from the power supply connected between the terminals 3 and 4. The operational amplifiers 15,16 operate as an impedance converter to increase the AC impedance from the terminals 1,2 to the terminals 3,4 via the resistors 5,7,6,8. Further, the capacitor 25 and its surrounding resistor constitute a low pass filter so that the differential amplifiers 19,20 are not operated to the differential AC signal between the terminals 1,2. Thus, no AC signal flows to the transistors 9,10 and the terminals 1,3 and 2,4 are high in impedance to AC signal.
JP6026078A 1978-05-19 1978-05-19 Supply circuit for communication current Pending JPS54151309A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6026078A JPS54151309A (en) 1978-05-19 1978-05-19 Supply circuit for communication current

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6026078A JPS54151309A (en) 1978-05-19 1978-05-19 Supply circuit for communication current

Publications (1)

Publication Number Publication Date
JPS54151309A true JPS54151309A (en) 1979-11-28

Family

ID=13137006

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6026078A Pending JPS54151309A (en) 1978-05-19 1978-05-19 Supply circuit for communication current

Country Status (1)

Country Link
JP (1) JPS54151309A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4414433A (en) * 1980-06-20 1983-11-08 Sony Corporation Microphone output transmission circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5260510A (en) * 1975-11-10 1977-05-19 Post Office Current supplying circuit of transmission bridge for telephone switching system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5260510A (en) * 1975-11-10 1977-05-19 Post Office Current supplying circuit of transmission bridge for telephone switching system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4414433A (en) * 1980-06-20 1983-11-08 Sony Corporation Microphone output transmission circuit

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