DK486180A - AMPLIFIER coupling with predetermined internal AC resistor - Google Patents

AMPLIFIER coupling with predetermined internal AC resistor

Info

Publication number
DK486180A
DK486180A DK486180A DK486180A DK486180A DK 486180 A DK486180 A DK 486180A DK 486180 A DK486180 A DK 486180A DK 486180 A DK486180 A DK 486180A DK 486180 A DK486180 A DK 486180A
Authority
DK
Denmark
Prior art keywords
line
transistor
transmission line
resistor
amplifier circuit
Prior art date
Application number
DK486180A
Other languages
Danish (da)
Inventor
B Rall
Original Assignee
Licentia Gmbh
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 Licentia Gmbh filed Critical Licentia Gmbh
Publication of DK486180A publication Critical patent/DK486180A/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/738—Interface circuits for coupling substations to external telephone lines
    • H04M1/76—Compensating for differences in line impedance

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)

Abstract

1. Amplifier circuit of predeterminable alternating current internal resistance with remote supply through a transmission line (a, b), over which an alternating current signal from or to the amplifier circuit is transmitted simultaneously with the supply current, particularly for electronic telephone instruments, in which the current of an impedance connected between the negative line (a) and the positive line (b) of the transmission line is fed as negative feedback to the amplifier circuit (A) and the predetermined alternating current internal resistance is formed through the output stage of the amplifier circuit (A) in consequence of the negative feedback, characterized thereby, that the impedance consists of the series connection (23, 24) of an ohmic resistor (23) with a capacitor (24), that the amplifier circuit is built up with two NPN-transistors (16, 18), wherein the emitter of the first transistor (18) is connected with the negative line (a) of the transmission line, the collector for one thing through a constant current source (17) with the positive line (b) of the transmission line and for the other with the base of the second transistor (16), the collector of the second transistor with the positive line (b) of the transmission line and the emitter of the second transistor (16) for ont thing through a first resistor (15) with the negative line (a) of the transmission line and for the other through a second resistor (14) for one thing with the base of the first transistor (18) and for the other through a third resistor (13) with a signal source (11, 13), that the capacitor (24) of the series connection (23, 24) is connected by its free end to the positive line (b) of the transmission line and the resistor (23) to a diode (22) of a current-imaging circuit, which is connected to the negative line (a), consists of a diode (22) and a third NPN-transistor (21) and in which the collector of the third transistor (21) is connected for one thing through a second constant current source (19) with the positive line (b) of the transmission line and for the other with the base of the first transistor (18) and that a constant current source (25) is connected in parallel with the capacitor (24) of the series connection (23, 24) and drives a constant current through the ohmic resistor (23) and a parallel regulator (26 to 28), which is connected between the lines (a, b) of the transmission line, is connected between the ohmic resistor (23) and the capacitor (24).
DK486180A 1979-11-16 1980-11-14 AMPLIFIER coupling with predetermined internal AC resistor DK486180A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19792946306 DE2946306A1 (en) 1979-11-16 1979-11-16 AMPLIFIER CIRCUIT WITH VOGEBLE AC INTERNAL RESISTANCE

Publications (1)

Publication Number Publication Date
DK486180A true DK486180A (en) 1981-05-17

Family

ID=6086165

Family Applications (1)

Application Number Title Priority Date Filing Date
DK486180A DK486180A (en) 1979-11-16 1980-11-14 AMPLIFIER coupling with predetermined internal AC resistor

Country Status (4)

Country Link
EP (1) EP0029134B1 (en)
AT (1) ATE4404T1 (en)
DE (1) DE2946306A1 (en)
DK (1) DK486180A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3401730A1 (en) * 1984-01-19 1985-07-25 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Amplifier circuit with predeterminable internal AC impedance
US5049764A (en) * 1990-01-25 1991-09-17 North American Philips Corporation, Signetics Div. Active bypass for inhibiting high-frequency supply voltage variations in integrated circuits

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL6412481A (en) * 1963-10-30 1965-05-03
GB1350205A (en) * 1970-07-24 1974-04-18 Post Office Telephone subscribers instrument circuits
SE386341B (en) * 1974-03-29 1976-08-02 Ericsson Telefon Ab L M CONNECTION DEVICE FOR A TELEPHONE DEVICE INCLUDING A DC CONVERTER.
CH592392A5 (en) * 1975-09-30 1977-10-31 Sodeco Compteurs De Geneve Telephone circuit without inductances - couples microphone amplifiers output to subscriber line and consists of DC feedback transistor in series with Zener diode
DE2610844A1 (en) * 1976-03-15 1977-09-22 Herbert Schoenke Integrated microphone amplifier for telephone instruments - has output directly connected to microphone terminals and includes negative feedback circuit
US4071713A (en) * 1976-12-27 1978-01-31 Northern Telecom Limited Telephone speech network
CA1056970A (en) * 1977-01-10 1979-06-19 Northern Telecom Limited Electronic network for telephone set

Also Published As

Publication number Publication date
EP0029134A1 (en) 1981-05-27
EP0029134B1 (en) 1983-08-03
ATE4404T1 (en) 1983-08-15
DE2946306A1 (en) 1981-05-21
DE2946306C2 (en) 1987-02-26

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Legal Events

Date Code Title Description
ATS Application withdrawn