GB743024A - Improvements in or relating to telephone apparatus - Google Patents

Improvements in or relating to telephone apparatus

Info

Publication number
GB743024A
GB743024A GB1824853A GB1824853A GB743024A GB 743024 A GB743024 A GB 743024A GB 1824853 A GB1824853 A GB 1824853A GB 1824853 A GB1824853 A GB 1824853A GB 743024 A GB743024 A GB 743024A
Authority
GB
United Kingdom
Prior art keywords
substation
line current
resistance
transistor amplifier
linear
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
GB1824853A
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.)
ARTHUR FREDERICK JONES
General Electric Co PLC
Original Assignee
ARTHUR FREDERICK JONES
General Electric Co PLC
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 ARTHUR FREDERICK JONES, General Electric Co PLC filed Critical ARTHUR FREDERICK JONES
Priority to GB1824853A priority Critical patent/GB743024A/en
Priority to FR1108780D priority patent/FR1108780A/en
Publication of GB743024A publication Critical patent/GB743024A/en
Expired 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
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
    • 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

Abstract

743,024. Substation circuits. GENERAL ELECTRIC CO., Ltd., and JONES, A. F. June 29, 1954 [July 1, 1953], No. 18248/53. Drawings to Specification. Class 40 (4). [Also in Group XL (c)] At a substation in a central-battery system a transistor amplifier (see Group XL (c)) is connected between the microphone and the line terminals and is operated by an electric supply derived from the line current, a non-linear resistance element being provided in order to minimize variations in this supply caused by variations in line current on lines of different lengths. The operating potential for the transistor amplifier is developed across a resistance which is traversed by a portion of the line current, this resistance being shunted by a path containing the non-linear element which is preferably a thermistor. The non- linear element may be used to stabilize the input and output of the substation as described in Specification 707,492. The invention may be applied to substation circuits of known anti-side-tone types, such as that described in Specification 340,693.
GB1824853A 1953-07-01 1953-07-01 Improvements in or relating to telephone apparatus Expired GB743024A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB1824853A GB743024A (en) 1953-07-01 1953-07-01 Improvements in or relating to telephone apparatus
FR1108780D FR1108780A (en) 1953-07-01 1954-06-30 Telephone device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1824853A GB743024A (en) 1953-07-01 1953-07-01 Improvements in or relating to telephone apparatus

Publications (1)

Publication Number Publication Date
GB743024A true GB743024A (en) 1956-01-04

Family

ID=10109204

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1824853A Expired GB743024A (en) 1953-07-01 1953-07-01 Improvements in or relating to telephone apparatus

Country Status (2)

Country Link
FR (1) FR1108780A (en)
GB (1) GB743024A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2894075A (en) * 1955-04-05 1959-07-07 Kunckel Heinz Telephone set
US3028452A (en) * 1957-01-15 1962-04-03 Automatic Elect Lab Loudspeaking telephone using transistors
US3068325A (en) * 1956-06-19 1962-12-11 Autophon Ag Telephone sub-stations including transistors

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2894075A (en) * 1955-04-05 1959-07-07 Kunckel Heinz Telephone set
US3068325A (en) * 1956-06-19 1962-12-11 Autophon Ag Telephone sub-stations including transistors
US3028452A (en) * 1957-01-15 1962-04-03 Automatic Elect Lab Loudspeaking telephone using transistors

Also Published As

Publication number Publication date
FR1108780A (en) 1956-01-17

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