GB939293A - Improvements in telephone sets of the loud-speaking type - Google Patents

Improvements in telephone sets of the loud-speaking type

Info

Publication number
GB939293A
GB939293A GB10601/60A GB1060160A GB939293A GB 939293 A GB939293 A GB 939293A GB 10601/60 A GB10601/60 A GB 10601/60A GB 1060160 A GB1060160 A GB 1060160A GB 939293 A GB939293 A GB 939293A
Authority
GB
United Kingdom
Prior art keywords
line
loud
amplifier
microphone
secretary
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
GB10601/60A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables 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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Publication of GB939293A publication Critical patent/GB939293A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/001—Two-way communication systems between a limited number of parties
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)

Abstract

939,293. Intercommunication systems. STANDARD TELEPHONES & CABLES Ltd. March 25, 1960 [March 26, 1959], No. 10601/60. Class 40 (4). In a substation equipped for " hands-free " loud-speaker and microphone operation using transmit and receive amplifiers, the depression of a push-button key enables the exchange line to be held and an interim conversation to take place with a secretary or the like over two oneway microphone-amplifier-loud-speaker links. On the restoration of the push button key the original conversation over the exchange line may be continued. The embodiment described includes two keys K1 and K2, the contacts of K1 being shown in the normal condition and those of K2 in the operated condition. With K1 and K2 both normal the telephone set 3 is connected to the exchange line 1, 2 and may operate as a normal set. Depression of key K1 switches the line to the hybrid 4, incoming currents from line being amplified at 6 and applied to the loudspeaker 8, while outgoing speech currents from the microphone 7 are amplified at 5 and applied via the hybrid 4 to the line. To speak with the secretary, keys K1 and K2 are depressed whereupon the output of amplifier 5 is switched to the secretary's loud-speaker 9, and her microphone is connected to the input of amplifier 6. the exchange line being held by the loop presented by the line input winding of the hybrid 4. The closure of contacts g of K2 sets the gain of amplifier 6 at a predetermined value.
GB10601/60A 1959-03-26 1960-03-25 Improvements in telephone sets of the loud-speaking type Expired GB939293A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT510759 1959-03-26

Publications (1)

Publication Number Publication Date
GB939293A true GB939293A (en) 1963-10-09

Family

ID=11117613

Family Applications (1)

Application Number Title Priority Date Filing Date
GB10601/60A Expired GB939293A (en) 1959-03-26 1960-03-25 Improvements in telephone sets of the loud-speaking type

Country Status (3)

Country Link
DE (1) DE1134120B (en)
FR (1) FR1251964A (en)
GB (1) GB939293A (en)

Also Published As

Publication number Publication date
FR1251964A (en) 1961-01-20
DE1134120B (en) 1962-08-02

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