GB1320489A - Fire alarm system - Google Patents

Fire alarm system

Info

Publication number
GB1320489A
GB1320489A GB2654671*A GB2654671A GB1320489A GB 1320489 A GB1320489 A GB 1320489A GB 2654671 A GB2654671 A GB 2654671A GB 1320489 A GB1320489 A GB 1320489A
Authority
GB
United Kingdom
Prior art keywords
lines
zener
diode
scr
detector
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
GB2654671*A
Other languages
English (en)
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.)
Nittan Co Ltd
Original Assignee
Nittan 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
Priority claimed from JP3384370A external-priority patent/JPS4814519B1/ja
Priority claimed from JP7314270A external-priority patent/JPS4929798B1/ja
Application filed by Nittan Co Ltd filed Critical Nittan Co Ltd
Publication of GB1320489A publication Critical patent/GB1320489A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B25/00—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
    • G08B25/01—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
    • G08B25/018—Sensor coding by detecting magnitude of an electrical parameter, e.g. resistance
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion

Landscapes

  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fire Alarms (AREA)
  • Alarm Systems (AREA)
GB2654671*A 1970-04-18 1971-04-19 Fire alarm system Expired GB1320489A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP3266970 1970-04-18
JP3384370A JPS4814519B1 (enExample) 1970-04-22 1970-04-22
JP7314270A JPS4929798B1 (enExample) 1970-08-22 1970-08-22

Publications (1)

Publication Number Publication Date
GB1320489A true GB1320489A (en) 1973-06-13

Family

ID=27287807

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2654671*A Expired GB1320489A (en) 1970-04-18 1971-04-19 Fire alarm system

Country Status (4)

Country Link
US (1) US3676877A (enExample)
CA (1) CA934842A (enExample)
FR (1) FR2086173B1 (enExample)
GB (1) GB1320489A (enExample)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE402660B (sv) * 1970-11-12 1978-07-10 Securitas Int Ab Brandalarmanleggning
US3978461A (en) * 1975-05-12 1976-08-31 Firetek Corporation Three wire detection circuit
DE2638068C3 (de) * 1976-08-24 1986-11-13 Siemens AG, 1000 Berlin und 8000 München Brandmeldeanlage mit mehreren über eine Meldeschleife betreibbaren Meldern
DE2641489C2 (de) * 1976-09-15 1984-05-30 Siemens AG, 1000 Berlin und 8000 München Verfahren zur Übertragung von Meßwerten in einem Brandmeldesystem
US4134111A (en) * 1976-12-16 1979-01-09 N.V. Tools Limited Aerosol detector and method
US4091363A (en) * 1977-01-03 1978-05-23 Pittway Corporation Self-contained fire detector with interconnection circuitry
US4385287A (en) * 1979-12-07 1983-05-24 Securicor Granley Systems Limited Multiple alarm condition detection and signalling
US4349751A (en) * 1980-02-11 1982-09-14 Bell Telephone Laboratories, Incorporated Control circuitry using a pull-down transistor for high voltage solid-state switches
US7190617B1 (en) 1989-04-13 2007-03-13 Sandisk Corporation Flash EEprom system
DE69033438T2 (de) * 1989-04-13 2000-07-06 Sandisk Corp., Santa Clara Austausch von fehlerhaften Speicherzellen einer EEprommatritze
US7447069B1 (en) 1989-04-13 2008-11-04 Sandisk Corporation Flash EEprom system
FR2723234B1 (fr) * 1994-07-29 1996-10-18 Lewiner Jacques Dispositif de detection d'alarme a boucles de courant, et balise de reperage de sous-zone pour un tel dispositif

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900628A (en) * 1956-01-27 1959-08-18 Westinghouse Electric Corp Multiple fault indicating system
US2987712A (en) * 1957-09-12 1961-06-06 Itt Fault alarm system
US3500469A (en) * 1966-02-11 1970-03-10 Protection Controls Inc Fault indicating system for a plurality of monitored devices
US3426217A (en) * 1966-05-26 1969-02-04 Us Army Breakwire signal conditioner
US3527987A (en) * 1967-10-23 1970-09-08 Gen Electric Monitor circuit for detecting the occurrence of one or more of a plurality of events in a system

Also Published As

Publication number Publication date
CA934842A (en) 1973-10-02
DE2118304B2 (de) 1973-02-01
FR2086173A1 (enExample) 1971-12-31
US3676877A (en) 1972-07-11
DE2118304A1 (de) 1971-11-04
FR2086173B1 (enExample) 1975-01-17

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee