GB516114A - Improvements in or relating to alternating current signalling systems - Google Patents

Improvements in or relating to alternating current signalling systems

Info

Publication number
GB516114A
GB516114A GB1510238A GB1510238A GB516114A GB 516114 A GB516114 A GB 516114A GB 1510238 A GB1510238 A GB 1510238A GB 1510238 A GB1510238 A GB 1510238A GB 516114 A GB516114 A GB 516114A
Authority
GB
United Kingdom
Prior art keywords
frequency
relay
signal
receiver
voice
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
GB1510238A
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
Priority to BE434428D priority Critical patent/BE434428A/xx
Priority to NL58054D priority patent/NL58054C/xx
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB1510238A priority patent/GB516114A/en
Priority to FR854916D priority patent/FR854916A/en
Publication of GB516114A publication Critical patent/GB516114A/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
    • H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
    • H04Q1/453—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling in which m-out-of-n signalling frequencies are transmitted
    • H04Q1/4535—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling in which m-out-of-n signalling frequencies are transmitted with an additional signal transmitted for voice protection

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Telephonic Communication Services (AREA)

Abstract

516,114. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd., and WRIGHT, E. P. G. May 20, 1938, No. 15102. [Class 40 (iv] . In a voice-frequency dialling and signalling system in which the receiver is inoperative until it has received a prolonged voice-frequency " prefix " signal, means are provided :for preventing a succession of impulses of " prefix " frequency from acting cumulatively so as to bring the. receiver to its operative condition. As shown, a relay XY which responds to currents of signal frequency interrupts the circuit of a normally energized slow-to release relay RB and makes that of a slow-to release relay RC. If the energization of XY does not persist for the full duration of an effective prefix signal a circuit is made for RH which holds itself and RB until the line has been quiescent long enoughto release RC. The relay RB, the relapse of which brings the receiver into its operative condition, cannot therefore be released by any number of rapidly recurring impulses if the first one is too short. Relay G responds to voice-frequencies other than the signal-frequency and holds RB when these are present. Specification 489,545 is referred to.
GB1510238A 1938-05-20 1938-05-20 Improvements in or relating to alternating current signalling systems Expired GB516114A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE434428D BE434428A (en) 1938-05-20
NL58054D NL58054C (en) 1938-05-20
GB1510238A GB516114A (en) 1938-05-20 1938-05-20 Improvements in or relating to alternating current signalling systems
FR854916D FR854916A (en) 1938-05-20 1939-05-17 Electrical communications systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1510238A GB516114A (en) 1938-05-20 1938-05-20 Improvements in or relating to alternating current signalling systems

Publications (1)

Publication Number Publication Date
GB516114A true GB516114A (en) 1939-12-22

Family

ID=10053070

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1510238A Expired GB516114A (en) 1938-05-20 1938-05-20 Improvements in or relating to alternating current signalling systems

Country Status (4)

Country Link
BE (1) BE434428A (en)
FR (1) FR854916A (en)
GB (1) GB516114A (en)
NL (1) NL58054C (en)

Also Published As

Publication number Publication date
BE434428A (en)
NL58054C (en)
FR854916A (en) 1940-04-27

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