SE7807783L - ELECTRONIC CIRCUIT IN A TELEPHONE SWITCH FOR POWER SUPPLY OF TELEPHONE CIRCUITS - Google Patents

ELECTRONIC CIRCUIT IN A TELEPHONE SWITCH FOR POWER SUPPLY OF TELEPHONE CIRCUITS

Info

Publication number
SE7807783L
SE7807783L SE7807783A SE7807783A SE7807783L SE 7807783 L SE7807783 L SE 7807783L SE 7807783 A SE7807783 A SE 7807783A SE 7807783 A SE7807783 A SE 7807783A SE 7807783 L SE7807783 L SE 7807783L
Authority
SE
Sweden
Prior art keywords
line
telephone
power supply
electronic circuit
senses
Prior art date
Application number
SE7807783A
Other languages
Swedish (sv)
Other versions
SE420039B (en
Inventor
L Hammarberg
Original Assignee
Ellemtel Utvecklings Ab
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 Ellemtel Utvecklings Ab filed Critical Ellemtel Utvecklings Ab
Priority to SE7807783A priority Critical patent/SE420039B/en
Publication of SE7807783L publication Critical patent/SE7807783L/en
Publication of SE420039B publication Critical patent/SE420039B/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

An electric circuit arrangement which is part of a telephone exchange and is connected to a power source for supplying current to the telephone sets connected to the exchange. The circuit arrangement contains two differential amplifiers OP1, OP2, one of which OP1 senses the feed current I to the line by detecting the voltage drop across a resistance r, directly connected to the line. The second differential amplifier OP2 senses any voltage changes across the line Le and sends a control quantity to an emitter sensor T connected in series between the power source so that the line current changes in dependence on the voltage change across the line. The circuit thus acts as a simulated impedance for the transverse line signals. <IMAGE>
SE7807783A 1978-07-13 1978-07-13 Electronic circuit arrangement in a telephone exchange for current supply SE420039B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
SE7807783A SE420039B (en) 1978-07-13 1978-07-13 Electronic circuit arrangement in a telephone exchange for current supply

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7807783A SE420039B (en) 1978-07-13 1978-07-13 Electronic circuit arrangement in a telephone exchange for current supply

Publications (2)

Publication Number Publication Date
SE7807783L true SE7807783L (en) 1980-01-14
SE420039B SE420039B (en) 1981-09-07

Family

ID=20335439

Family Applications (1)

Application Number Title Priority Date Filing Date
SE7807783A SE420039B (en) 1978-07-13 1978-07-13 Electronic circuit arrangement in a telephone exchange for current supply

Country Status (1)

Country Link
SE (1) SE420039B (en)

Also Published As

Publication number Publication date
SE420039B (en) 1981-09-07

Similar Documents

Publication Publication Date Title
SE8008239L (en) DEVICE FOR CONTROLING A PHONE LINE FEED POWER
JPS5718109A (en) Sound volume controlling circuit
JPS5760710A (en) Adjusting circuit for input bias of amplifier
DE3260920D1 (en) Sliding class a broadband linear amplifier with low power consumption, and circuit comprising at least one such amplifier
KR920020831A (en) Differential amplifier
KR900001117A (en) Automatic gain control circuit
SE7807783L (en) ELECTRONIC CIRCUIT IN A TELEPHONE SWITCH FOR POWER SUPPLY OF TELEPHONE CIRCUITS
SE7902832L (en) SUBSCRIBER CIRCUIT INCLUDING A SYMMETRIC POWER AMPLIFIER FOR SUPPLYING A SUBSCRIBER MANAGEMENT
ATE47945T1 (en) SUBSCRIPTION CIRCUIT.
JPS555552A (en) Dc reproducing circuit
GB858116A (en) Improvements relating to transistor switching circuits
JPS52102659A (en) Differential amplifier
JPS5494213A (en) Amplifier for transmitter
KR920010295A (en) Current threshold detector circuit
GB1369688A (en) Remotely controllable electronic variable resistance
JPS5696307A (en) Constant-current circuit
SU684717A1 (en) Amplifier
JPS54151309A (en) Supply circuit for communication current
JPS5555608A (en) Automatic gain control circuit
JPS56168407A (en) Amplifier
JPS5797212A (en) Gain control circuit
JPS5599874A (en) Communication current supply circuit
JPS5769932A (en) Current switching type logical circuit
DE3888810D1 (en) Transmission circuit.
JPS5792909A (en) Power amplifying circuit

Legal Events

Date Code Title Description
NAL Patent in force

Ref document number: 7807783-1

Format of ref document f/p: F

NUG Patent has lapsed

Ref document number: 7807783-1

Format of ref document f/p: F