GB1065941A - Improvements in or relating to telephone systems - Google Patents

Improvements in or relating to telephone systems

Info

Publication number
GB1065941A
GB1065941A GB160265A GB160265A GB1065941A GB 1065941 A GB1065941 A GB 1065941A GB 160265 A GB160265 A GB 160265A GB 160265 A GB160265 A GB 160265A GB 1065941 A GB1065941 A GB 1065941A
Authority
GB
United Kingdom
Prior art keywords
diodes
temperature coefficient
resistors
series
shunt
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.)
Expired
Application number
GB160265A
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.)
Siemens AG
Original Assignee
Siemens AG
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 Siemens AG filed Critical Siemens AG
Publication of GB1065941A publication Critical patent/GB1065941A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/40—Artificial lines; Networks simulating a line of certain length
    • 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)
  • Computer Networks & Wireless Communication (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Networks Using Active Elements (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

1,065,941. Transmission line impedance compensation. SIEMENS A.G. Jan. 14, 1965 [Jan. 15, 1964], No. 1602/65. Headings H4K and H4R. A four-terminal attenuator network for automatically compensating for differences in line impedance has non-linear positive temperature coefficient resistors K in the series paths which by biasing diodes D by an amount depending on the line current flowing in them vary the shunt resistance of the network. A symmetrical circuit. as shown in Fig. 1 is suitable for siting near the exchange, but near to a subscriber sub-set an asymmetrical circuit is used obtained by omitting one of the series resistors K and one set of shunt diodes D, Fig. 2 (not shown). In another arrangement of an asymmetrical circuit (Fig. 3, not shown) the remaining shunt diodes may be replaced by a negative temperature coefficient resistor having a heating coil in the free series path. In the arrangement of Fig. 1 the diodes may be replaced by negative temperature coefficient resistors.
GB160265A 1964-01-15 1965-01-14 Improvements in or relating to telephone systems Expired GB1065941A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DES0089064 1964-01-15

Publications (1)

Publication Number Publication Date
GB1065941A true GB1065941A (en) 1967-04-19

Family

ID=7514858

Family Applications (1)

Application Number Title Priority Date Filing Date
GB160265A Expired GB1065941A (en) 1964-01-15 1965-01-14 Improvements in or relating to telephone systems

Country Status (6)

Country Link
BE (1) BE658384A (en)
CH (1) CH416754A (en)
DE (1) DE1437449B2 (en)
GB (1) GB1065941A (en)
NL (1) NL6413946A (en)
SE (1) SE331119B (en)

Also Published As

Publication number Publication date
DE1437449A1 (en) 1968-10-24
NL6413946A (en) 1965-07-16
DE1437449B2 (en) 1972-06-15
CH416754A (en) 1966-07-15
BE658384A (en) 1965-07-15
SE331119B (en) 1970-12-14

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