US2126529A - Transmission system - Google Patents

Transmission system Download PDF

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Publication number
US2126529A
US2126529A US101058A US10105836A US2126529A US 2126529 A US2126529 A US 2126529A US 101058 A US101058 A US 101058A US 10105836 A US10105836 A US 10105836A US 2126529 A US2126529 A US 2126529A
Authority
US
United States
Prior art keywords
resistance
equalizer
amplifier
oven
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 - Lifetime
Application number
US101058A
Other languages
English (en)
Inventor
Harold S Black
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.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
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
Priority to NL47983D priority Critical patent/NL47983C/xx
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US101058A priority patent/US2126529A/en
Priority to GB21189/37A priority patent/GB479668A/en
Priority to CH209243D priority patent/CH209243A/de
Priority to FR826794D priority patent/FR826794A/fr
Application granted granted Critical
Publication of US2126529A publication Critical patent/US2126529A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/10—Control of transmission; Equalising by pilot signal

Definitions

  • This invention relates to communication systems and has for its object to improve transmission in such systems.
  • the transmission is often controlled by means of an equalizer in the input circuit which is in turn.
  • an input equalizer is controlled through the medium of thermally sensitive elements, for example, particularly elements of silver sulphide or boron so arranged that whenever the series resistance is changed the shunt resistance is automatically changed to such a value that their product is held constant.
  • thermally sensitive elements for example, particularly elements of silver sulphide or boron so arranged that whenever the series resistance is changed the shunt resistance is automatically changed to such a value that their product is held constant.
  • the pilot frequency is picked up from the outgoing conductors 8 and 9 by means of the band pass filter H and fed through the full wave rectiiier H to relay l3.
  • thermoly sensitive resistance M In place of an adjustable resistance in the series element 4 of the equalizer, there is substituted a thermally sensitive resistance M. Similarly a thermally sensitive resistance I5 is substituted for an adjustable resistance in the shunt element 5 of equalizer 3.
  • Resistance I4 is enclosed in an oven 20 in which is also included a second similar thermally sensitive resistance It and a heating element II which enwraps both resistances l4 and I6.
  • Resistance 5 is likewise associated with a second similar thermally sensitive resistance I! and a heating element l9, all enclosed in an oven 2
  • Thermal resistances l6 and N form opposite arms of a Wheatstone bridge of which resistances 22 and 23, which are unaffected by temperature, form the alternate arms.
  • the bridge receives current from the alternating current generator 26 through transformer 21 and the diagonal of the bridge includes full wave rectifier 2t and relay 25.
  • Relay l3 controls heater l8 and relay 25 controls heater l9.
  • resistance 4 there are three conditions which may exist with regard to resistance 4 and therefore with regard to resistance l6. Namely, it may be constant, it may be increasing or it maybe decreasing. If resistance M is constant and oven 2
  • must be able to increase in temperature faster than oven 20 can decrease in temperature, which would naturally be the case.
  • the reflection coefflcient at the input to equalizer 3 referred to the resistance of the equalizer is better than that of the equalizers termination, the improvement being equal to the amplification or current ratio corresponding to twice the insertion loss of the equalizer. For example, if the equalizer loss be 3 db., this improvement would be fourfold or in other words the refiection coeflicient at the input would be that of the termination.
  • an amplifier in the input of said amplifier having a series resistance and a shunt resistance, and means for maintaining the output of said amplifier constant, comprising means under the control of said output to vary said series and shunt resistances, while maintaining their product constant, said varying means including silver sulphide resistance units, and heating means for reciprocally varying the temperatures thereof.
  • an amplifier in the input of said amplifier, having a series resistance element and a shunt resistance element, and means for maintaining the output of said amplifier constant, comprising means under the control of said output to vary the value of said series and shunt resistance elements, while maintaining their product constant, saidvarying means comprising auxiliary resistance units of large temperature coeflicients of resistance in the opposite arms of a Wheatstone bridge.
  • equalizer in the input of said amplifier having a series resistance and a shunt resistance, means for maintaining the output of said amplifier constant, comprising means under the control of said output to vary the series and shunt resistances of said equalizer, while maintaining their product constant, said varying means comprising silver sulphide resistance units in the opposite arms of a Wheatstone bridge, and means controlled by said Wheatstone bridge to control the relative temperatures of said silver sulphide resistance units.
  • an amplifier in the input of said amplifier, said equalizer having a series element and a shunt element, and means for maintaining the output of said amplifier constant while preserving the proper characteristics for said equalizer comprising a temperature sensitive resistance in the series element of said equalizer, a temperature sensitive resistance in the shunt element of said equalizer, means under the control of the output of said amplifier to vary the temperature of said series temperature-sensitive resistance, a Wheatstone bridge associated with said series and shunt temperature sensitive resistances and means under the control of said bridge 'to vary the temperature of said shunt temperature sensitive resistance.
  • an amplifier an equalizer in the input of said amplifier, said equalizer having a series element and a shunt element, and means for maintaining the output of said amplifier constant while preserving the proper characteristics for said equalizer comprising a silver sulphide resistance in the series element.
  • a silver sulphide resistance in the shunt element of said equalizer means under the control of the output of said amplifier to vary the temperature of said series silver sulphide resistance, a Wheatstone bridge associated with said series and shunt silver sulphide resistances and means under the control of said bridge to reciprocally vary the temperature of said shunt silver sulphide resistance.
  • an amplifier in the input of said amplifier, said equalizer having a series element and a shunt element, and means for maintaining the output of said amplifier constant while preserving the proper characteristics for said equalizer comprising a silver sulphide resistance in the series element of said equalizer, a silver sulphide resistance in the shunt element of said equalizer, said series silver sulphide resistance enclosed in an oven together with a first auxiliary silver sulphide resistance and a heater, said shunt silver sulphide resistance enclosed in a second oven together with asecond auxiliary silver sulphide resistance and a second heater, means under the control of the output of said amplifier to vary the temperature of said first oven, at Wheatstone bridge including said first and second auxiliary silver sulphide

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Thermistors And Varistors (AREA)
  • Networks Using Active Elements (AREA)
US101058A 1936-09-16 1936-09-16 Transmission system Expired - Lifetime US2126529A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL47983D NL47983C (fr) 1936-09-16
US101058A US2126529A (en) 1936-09-16 1936-09-16 Transmission system
GB21189/37A GB479668A (en) 1936-09-16 1937-07-30 Improvements in or relating to telephone or like transmission systems
CH209243D CH209243A (de) 1936-09-16 1937-09-14 Elektrische Wellenübertragungsanlage.
FR826794D FR826794A (fr) 1936-09-16 1937-09-15 Réseaux de transmission pour systèmes de signalisation électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US101058A US2126529A (en) 1936-09-16 1936-09-16 Transmission system

Publications (1)

Publication Number Publication Date
US2126529A true US2126529A (en) 1938-08-09

Family

ID=22282885

Family Applications (1)

Application Number Title Priority Date Filing Date
US101058A Expired - Lifetime US2126529A (en) 1936-09-16 1936-09-16 Transmission system

Country Status (5)

Country Link
US (1) US2126529A (fr)
CH (1) CH209243A (fr)
FR (1) FR826794A (fr)
GB (1) GB479668A (fr)
NL (1) NL47983C (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625606A (en) * 1947-11-25 1953-01-13 Bell Telephone Labor Inc Thermistor control circuit
US2994741A (en) * 1957-12-19 1961-08-01 Kallsson Bengt Erik Lennart Signal transmitting repeater

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625606A (en) * 1947-11-25 1953-01-13 Bell Telephone Labor Inc Thermistor control circuit
US2994741A (en) * 1957-12-19 1961-08-01 Kallsson Bengt Erik Lennart Signal transmitting repeater

Also Published As

Publication number Publication date
FR826794A (fr) 1938-04-08
NL47983C (fr)
GB479668A (en) 1938-02-09
CH209243A (de) 1940-03-31

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