GB433223A - Improvements in or relating to telephone systems - Google Patents

Improvements in or relating to telephone systems

Info

Publication number
GB433223A
GB433223A GB462934A GB462934A GB433223A GB 433223 A GB433223 A GB 433223A GB 462934 A GB462934 A GB 462934A GB 462934 A GB462934 A GB 462934A GB 433223 A GB433223 A GB 433223A
Authority
GB
United Kingdom
Prior art keywords
station
relay
calling
attendant
police
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
GB462934A
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
Priority to GB462934A priority Critical patent/GB433223A/en
Publication of GB433223A publication Critical patent/GB433223A/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
    • H04Q1/442—Signalling arrangements; Manipulation of signalling currents using alternate current with out-of-voice band signalling frequencies
    • H04Q1/4423—Signalling arrangements; Manipulation of signalling currents using alternate current with out-of-voice band signalling frequencies using one signalling frequency

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)

Abstract

433,223. Direct call systems. STANDARD TELEPHONES & CABLES, Ltd., 63, Aldwych, DIXON, A. E. J., 108, Holland Road, Stockwell, and SEARLE, A. M., 63, Aldwych, both in London. Feb. 12, 1934, No. 4629. [Class 40 (iv)] In a system in which one station calls another by transmitting a momentary signal to operate a calling device, manually-operable means is provided at the calling station, whereby an attendant may ascertain at will whether the calling device is in operation. The invention is described in connection with calls from a police station to police boxes. The station attendant plugs jack J, sends a pulse of ringing current, and withdraws the plug. At the police box, relay A energizes B and falls back, B being a relay of the type in which the armature remains operated after an energizing impulse has ceased and is released by sending a second impulse. Relay B energizes C and lights calling lamp SL. To ascertain the state of the calling lamp, the station attendant throws key K, and if the lamp is alight (C operated), a signal relay SG pulls up. When the call is answered, relay SG operates over the loop and the station attendant sends another pulse of ringing current to extinguish the calling lamp. A call from the police box operates SG in the ordinary manner.
GB462934A 1934-02-12 1934-02-12 Improvements in or relating to telephone systems Expired GB433223A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB462934A GB433223A (en) 1934-02-12 1934-02-12 Improvements in or relating to telephone systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB462934A GB433223A (en) 1934-02-12 1934-02-12 Improvements in or relating to telephone systems

Publications (1)

Publication Number Publication Date
GB433223A true GB433223A (en) 1935-08-12

Family

ID=9780767

Family Applications (1)

Application Number Title Priority Date Filing Date
GB462934A Expired GB433223A (en) 1934-02-12 1934-02-12 Improvements in or relating to telephone systems

Country Status (1)

Country Link
GB (1) GB433223A (en)

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