GB553935A - Improvements in or relating to voice-frequency signalling systems - Google Patents

Improvements in or relating to voice-frequency signalling systems

Info

Publication number
GB553935A
GB553935A GB5882/42A GB588242A GB553935A GB 553935 A GB553935 A GB 553935A GB 5882/42 A GB5882/42 A GB 5882/42A GB 588242 A GB588242 A GB 588242A GB 553935 A GB553935 A GB 553935A
Authority
GB
United Kingdom
Prior art keywords
voice
frequency
amplifier
cycles
condenser
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
GB5882/42A
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 GB553935A publication Critical patent/GB553935A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/18—Electrical details
    • H04Q1/30—Signalling arrangements; Manipulation of signalling currents
    • H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
    • H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
    • H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
    • H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)

Abstract

553,935. Voice - frequency signalling. STANDARD TELEPHONES & CABLES, Ltd. May 1, 1942, No. 5882. Convention date, April 19, 1941. [Class 40 (iv)] [Also in Group XL] A receiver for low frequency signals modulated on to voice frequency comprises a thermionic detector D coupled to a thermionic amplifier A through a resistance-condenser combination such as to ensure operation only after receipt of a number of low frequency pulses. In this way the amplifier is slowly unblocked at a rate which may be varied by varying the capacity of the condenser 11 and be such as to prevent unblocking of the amplifier by a transitory operation of the detector. The Specification gives data for a system operating at 1000 cycles interrupted at a frequency of 20 cycles. The secondary of the output transformer LF is tuned to 20 cycles by condenser 3 and retard coil 2 and the circuit completed by a rectifier 4 and relay 6.
GB5882/42A 1941-04-19 1942-05-01 Improvements in or relating to voice-frequency signalling systems Expired GB553935A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US389335A US2299279A (en) 1941-04-19 1941-04-19 Signaling system

Publications (1)

Publication Number Publication Date
GB553935A true GB553935A (en) 1943-06-10

Family

ID=23537833

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5882/42A Expired GB553935A (en) 1941-04-19 1942-05-01 Improvements in or relating to voice-frequency signalling systems

Country Status (2)

Country Link
US (1) US2299279A (en)
GB (1) GB553935A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2572814A (en) * 1950-01-06 1951-10-23 Marie K Laporte Telephone shell and signal light

Also Published As

Publication number Publication date
US2299279A (en) 1942-10-20

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