GB1379664A - Transmitter receiver - Google Patents

Transmitter receiver

Info

Publication number
GB1379664A
GB1379664A GB655672A GB655672A GB1379664A GB 1379664 A GB1379664 A GB 1379664A GB 655672 A GB655672 A GB 655672A GB 655672 A GB655672 A GB 655672A GB 1379664 A GB1379664 A GB 1379664A
Authority
GB
United Kingdom
Prior art keywords
loud
amplifier
handset
amplifiers
tap
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
GB655672A
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.)
CENTRAL TELEPHONE
Original Assignee
CENTRAL TELEPHONE
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 CENTRAL TELEPHONE filed Critical CENTRAL TELEPHONE
Publication of GB1379664A publication Critical patent/GB1379664A/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
    • H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets

Abstract

1379664 Loud-speaking telephones CENTRAL TELEPHONE 11 Feb 1972 [15 Dec 1971] 6556/72 Headings H4K and H4R In a loud-speaking telephone the microphone is connected to the tap M of the hybrid transformer 2 by an amplifier 8 which feeds the tap with a D.C. modulated by the microphone signal. The loud-speaker 11 is fed from the secondary of the transformer 2 via amplifier 10. Power is fed to the amplifiers from the line via rectifier bridges 7 and 14 with the receive amplifier supply isolated from the A.C. signal by chokes 12, 13. Preferably the amplifiers and loud-speaker are built into a subscriber's set having a handset which is alternatively connected into circuit by the subset hookswitch, Figs. 2 and 3 (not shown). Alternatively the handset and the amplifier may be connected to the line by respective hybrid transformers. The set may also have a secondary earphone (8<SP>1</SP>) connected in conventional manner.
GB655672A 1971-12-15 1972-02-11 Transmitter receiver Expired GB1379664A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7145024A FR2165032A5 (en) 1971-12-15 1971-12-15

Publications (1)

Publication Number Publication Date
GB1379664A true GB1379664A (en) 1975-01-08

Family

ID=9087507

Family Applications (1)

Application Number Title Priority Date Filing Date
GB655672A Expired GB1379664A (en) 1971-12-15 1972-02-11 Transmitter receiver

Country Status (4)

Country Link
DE (1) DE2208693A1 (en)
FR (1) FR2165032A5 (en)
GB (1) GB1379664A (en)
IT (1) IT947850B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4488006A (en) * 1982-07-01 1984-12-11 At&T Bell Laboratories Apparatus for controlling the application of telephone line power in a telephone set

Also Published As

Publication number Publication date
IT947850B (en) 1973-05-30
FR2165032A5 (en) 1973-08-03
DE2208693A1 (en) 1973-06-28

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee