EP0086182A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electronic impedance-matched line repeater
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1983-01-26
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Granted: —
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Expires: 2003-01-26
Abstract
Abstract An electronic line repeater for connecting a two-wire line to a subscriber exchange is impedance-matched to the two-wire side with the aid of a feedback circuit from the two-wire side of the repeater to the incoming four-wire side. The feedback includes a differential amplifier (F1) which senses the speech voltage drop on the two-wire side, and a resistor (R) connected to the line amplifier (F2) of the repeater. Impedance matching can be achieved by definite values of the gain provided by the differential amplifier and the line amplifier.
Inventors
- 👤 Lars Anders Lenell
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 14:22
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/001; H04M19/005; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/54; H04B1/58; H04B1/587
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
165 words
1 Electronic impedance-matched line repeater included in a two-wire- to four-wire converter for connecting a two-wire line to a telephone exchange including a two-wire side as well as an incoming and an outgoing four-wire side, the two-wire side of the repeater comprising an external line loop containing resistors connected as overvoltage protection and a balanced line amplifier (F2), the output side of which is connected in series with said resistors (Rl) and the input side of which forms one (incoming) four-wire path via a first resistor (R), characterized in that a feedback loop is provided for impedance matching to the two-wire line, and constitutes a differential amplifier circuit (Fl) with two input pairs, of which one is connected directly to the two-wire input and the other is connected across the output side of the line amplifier, the output of the differential amplifier (Fl) being connected via a second resistor (R) to the input of the line amplifier, and furthermore forms the second (outgoing) four-wire path.
Claim 2
Dependent Claim
165 words
1 Electronic impedance-matched line repeater included in a two-wire- to four-wire converter for connecting a two-wire line to a telephone exchange including a two-wire side as well as an incoming and an outgoing four-wire side, the two-wire side of the repeater comprising an external line loop containing resistors connected as overvoltage protection and a balanced line amplifier (F2), the output side of which is connected in series with said resistors (Rl) and the input side of which forms one (incoming) four-wire path via a first resistor (R), characterized in that a feedback loop is provided for impedance matching to the two-wire line, and constitutes a differential amplifier circuit (Fl) with two input pairs, of which one is connected directly to the two-wire input and the other is connected across the output side of the line amplifier, the output of the differential amplifier (Fl) being connected via a second resistor (R) to the input of the line amplifier, and furthermore forms the second (outgoing) four-wire path.
Claim 3
Dependent Claim
41 words
2 Electronic line repeater as claimed in claim 1, characterized in that said differential amplifier (Fl) has a low-ohmic output which, via the first and the second resistor (R) is connected to a low-ohmic output at one (incoming) four-wire side (OP4).
Claim 4
Dependent Claim
22 words
3 Electronic line repeater as claimed in claim 2, characterized in that said first and second resistors (R) have the same resistance.
Claim 5
Dependent Claim
31 words
4 Electronic line repeater as claimed in claims 1-3, characterized in that the amplification of the differential amplifier (F1) is frequency-dependent, so that complex impedance-matching with the two-wire side is obtained.
References Cited (Backward Citations)
No citation records indexed.
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