GB333374A - Improvements in or relating to telephone transmission systems - Google Patents

Improvements in or relating to telephone transmission systems

Info

Publication number
GB333374A
GB333374A GB2314329A GB2314329A GB333374A GB 333374 A GB333374 A GB 333374A GB 2314329 A GB2314329 A GB 2314329A GB 2314329 A GB2314329 A GB 2314329A GB 333374 A GB333374 A GB 333374A
Authority
GB
United Kingdom
Prior art keywords
circuit
systems
responder
phantom
generator
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
GB2314329A
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.)
Automatic Telephone Manufacturing Co Ltd
Original Assignee
Automatic Telephone Manufacturing Co Ltd
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 Automatic Telephone Manufacturing Co Ltd filed Critical Automatic Telephone Manufacturing Co Ltd
Priority to GB2314329A priority Critical patent/GB333374A/en
Publication of GB333374A publication Critical patent/GB333374A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M7/00—Arrangements for interconnection between switching centres
    • H04M7/08—Arrangements for interconnection between switching centres for phantom working

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

333,374. Automatic Telephone Manufacturing Co., Ltd., Rayner, T. R., and Smith, J. July 27, 1929. Manual exchange systems; phantom-circuit systems. - In systems employing repeaters audio-frequency currents under manual control are used for signalling, the signalling current and the responder being automatically disconnected when the speaking circuit is completed. The invention is described as applied to a system employing two physical circuits A and B with a phantom C. To signal from S1 to S2 over circuit A a plug is inserted in J1 and key RK1 is thrown. Generator G1 is thus connected to the channel A and current of audio frequency (about 500 cycles per second) is transmitted through the springs J2 to transformer T2 whence it reaches the grid of valve V2 and operates DR2 to light calling lamp CL2. When the answering plug is inserted in J2 the responder is disconnected and when the ring- ing key RK1 is restored the generator is cut out of the circuit.
GB2314329A 1929-07-27 1929-07-27 Improvements in or relating to telephone transmission systems Expired GB333374A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2314329A GB333374A (en) 1929-07-27 1929-07-27 Improvements in or relating to telephone transmission systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2314329A GB333374A (en) 1929-07-27 1929-07-27 Improvements in or relating to telephone transmission systems

Publications (1)

Publication Number Publication Date
GB333374A true GB333374A (en) 1930-08-14

Family

ID=10190844

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2314329A Expired GB333374A (en) 1929-07-27 1929-07-27 Improvements in or relating to telephone transmission systems

Country Status (1)

Country Link
GB (1) GB333374A (en)

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