GB904658A - Absence signal device for telephone - Google Patents

Absence signal device for telephone

Info

Publication number
GB904658A
GB904658A GB3744658A GB3744658A GB904658A GB 904658 A GB904658 A GB 904658A GB 3744658 A GB3744658 A GB 3744658A GB 3744658 A GB3744658 A GB 3744658A GB 904658 A GB904658 A GB 904658A
Authority
GB
United Kingdom
Prior art keywords
oscillator
line
nov
telephone
signal device
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
GB3744658A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of GB904658A publication Critical patent/GB904658A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/64—Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations
    • H04M1/65—Recording arrangements for recording a message from the calling party

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Telephonic Communication Services (AREA)

Abstract

904,658. Substation equipment. MURAMATSU, H. Nov. 20, 1958 [Nov. 21, 1957], No. 37446/58. Class 40 (4). A switch 1 may be set to connect the incoming line A either to the normal telephone apparatus B or to an oscillator 14 which is normally biased to an inoperative position; when the line is connected to the oscillator, the reversal of potential on the arrival of an incoming call causes current to flow through the halfwave rectifier REC so that the oscillator 14 generates a signal which is transmitted over the line A to the calling subscriber as an indication of the absence of the called subscriber. In modifications. Figs. 5-7 (not shown), the oscillator operates only in the intervals in the intermittent calling signal.
GB3744658A 1957-11-21 1958-11-20 Absence signal device for telephone Expired GB904658A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2898257 1957-11-21

Publications (1)

Publication Number Publication Date
GB904658A true GB904658A (en) 1962-08-29

Family

ID=12263606

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3744658A Expired GB904658A (en) 1957-11-21 1958-11-20 Absence signal device for telephone

Country Status (1)

Country Link
GB (1) GB904658A (en)

Similar Documents

Publication Publication Date Title
ES446362A1 (en) Ring trip detector
GB843225A (en) Improvements in or relating to electrical systems for determining the condition of electrical devices
GB742209A (en) Transistor relay devices
FR1245071A (en) Telegraph signaling device for a telephone system
GB904658A (en) Absence signal device for telephone
GB1023832A (en) Signaling repeaters
GB1254258A (en) A circuit arrangement including a relaxation oscillator for alternately providing ringing-tone and supervisory signals to subscriber stations
GB1142982A (en) Telephone ringing circuit
GB655682A (en) Improvements in telephone exchange systems
GB971802A (en) Signalling system for substation apparatus
JPS5563157A (en) Automatic answering telephone system
GB1039668A (en) Improvements relating to telephone system substation circuits
GB834204A (en) Improvements in or relating to circuit arrangements for automatic telephone exchanges
GB641343A (en) Improvements in or relating to teleprinter exchange systems
GB777099A (en) Party line identification system
GB1051505A (en)
GB608856A (en) Rectifier arrangement
US3187109A (en) Voice frequency signalling system
GB647974A (en) Circuit arrangement for a subscriber's set of a telegraph system
GB707435A (en) Improvements in or relating to telephone systems
GB852193A (en) Improvements in or relating to burglar alarm systems
GB583277A (en) Improvements in electrical signalling systems
GB957456A (en) Circuit arrangement for a key-controlled intercommunication system of the type in which each substation set is provided with a facility for calling any other station
GB915973A (en) Improvements in or relating to automatic telephone switching systems
GB1251150A (en)