FR2235555A1 - Regulation of acoustic performance of telephones - employs a single varistor and provides level control - Google Patents

Regulation of acoustic performance of telephones - employs a single varistor and provides level control

Info

Publication number
FR2235555A1
FR2235555A1 FR7323709A FR7323709A FR2235555A1 FR 2235555 A1 FR2235555 A1 FR 2235555A1 FR 7323709 A FR7323709 A FR 7323709A FR 7323709 A FR7323709 A FR 7323709A FR 2235555 A1 FR2235555 A1 FR 2235555A1
Authority
FR
France
Prior art keywords
regulation
telephones
employs
level control
acoustic performance
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.)
Granted
Application number
FR7323709A
Other languages
French (fr)
Other versions
FR2235555B1 (en
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.)
PERSON JEAN MICHEL
Original Assignee
PERSON JEAN MICHEL
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 PERSON JEAN MICHEL filed Critical PERSON JEAN MICHEL
Priority to FR7323709A priority Critical patent/FR2235555A1/en
Publication of FR2235555A1 publication Critical patent/FR2235555A1/en
Application granted granted Critical
Publication of FR2235555B1 publication Critical patent/FR2235555B1/fr
Granted legal-status Critical Current

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)
  • Devices For Supply Of Signal Current (AREA)

Abstract

Regulation circuitry is particularly suitable for situations where lines to exchanges are short and hence tend to carry high currents due to their low ohmic resistance and sound levels can be unsuitably high. The figure shows in simplified form the exchange (1), (2), and (3) representing the subscriber's equipment. (21) is a variable resistor whose setting will depend on the voltage at the subscriber end and provide the required level of attenuation. (37) represents the varistor across the lines and (34) consists of a thermistor in parallel with a fixed resistor providing regulation of the supply. Resistance(12) may be formed by relays at the exchange.
FR7323709A 1973-06-28 1973-06-28 Regulation of acoustic performance of telephones - employs a single varistor and provides level control Granted FR2235555A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7323709A FR2235555A1 (en) 1973-06-28 1973-06-28 Regulation of acoustic performance of telephones - employs a single varistor and provides level control

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7323709A FR2235555A1 (en) 1973-06-28 1973-06-28 Regulation of acoustic performance of telephones - employs a single varistor and provides level control

Publications (2)

Publication Number Publication Date
FR2235555A1 true FR2235555A1 (en) 1975-01-24
FR2235555B1 FR2235555B1 (en) 1978-06-30

Family

ID=9121719

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7323709A Granted FR2235555A1 (en) 1973-06-28 1973-06-28 Regulation of acoustic performance of telephones - employs a single varistor and provides level control

Country Status (1)

Country Link
FR (1) FR2235555A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983003504A1 (en) * 1982-04-01 1983-10-13 Jaki, Ivan Supply circuit included in a dc-magnetized hybrid transformer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1402296A (en) * 1964-07-10 1965-06-11 Int Standard Electric Corp Improvements to telephone sets
FR1420110A (en) * 1964-01-15 1965-12-03 Siemens Ag Setup to automatically compensate for differences in attenuation between subscriber telephone lines of different lengths
FR1522554A (en) * 1967-03-17 1968-04-26 Fr Des Telephones Ericsson Soc Conversation current regulator for subscriber telephones

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1420110A (en) * 1964-01-15 1965-12-03 Siemens Ag Setup to automatically compensate for differences in attenuation between subscriber telephone lines of different lengths
FR1402296A (en) * 1964-07-10 1965-06-11 Int Standard Electric Corp Improvements to telephone sets
FR1522554A (en) * 1967-03-17 1968-04-26 Fr Des Telephones Ericsson Soc Conversation current regulator for subscriber telephones

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983003504A1 (en) * 1982-04-01 1983-10-13 Jaki, Ivan Supply circuit included in a dc-magnetized hybrid transformer
US4590334A (en) * 1982-04-01 1986-05-20 Telefonaktiebolaget Lm Ericsson Supply circuit included in a DC-magnetized hybrid transformer

Also Published As

Publication number Publication date
FR2235555B1 (en) 1978-06-30

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Legal Events

Date Code Title Description
ST Notification of lapse