GB1405615A - Fire alarms - Google Patents

Fire alarms

Info

Publication number
GB1405615A
GB1405615A GB3763372A GB3763372A GB1405615A GB 1405615 A GB1405615 A GB 1405615A GB 3763372 A GB3763372 A GB 3763372A GB 3763372 A GB3763372 A GB 3763372A GB 1405615 A GB1405615 A GB 1405615A
Authority
GB
United Kingdom
Prior art keywords
circuit
detector
alarm
fire
radiation
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
GB3763372A
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.)
Chubb Fire Ltd
Original Assignee
Chubb Fire Security 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
Application filed by Chubb Fire Security Ltd filed Critical Chubb Fire Security Ltd
Priority to GB3763372A priority Critical patent/GB1405615A/en
Priority to US00385708A priority patent/US3846772A/en
Priority to NO3132/73A priority patent/NO132564C/no
Priority to ZA735343A priority patent/ZA735343B/en
Priority to IL42930A priority patent/IL42930A/en
Priority to DE2340041A priority patent/DE2340041C2/en
Priority to AU59013/73A priority patent/AU476368B2/en
Priority to CA178,298A priority patent/CA1010969A/en
Priority to IT51932/73A priority patent/IT990203B/en
Priority to NL7311010A priority patent/NL7311010A/xx
Priority to DK439773A priority patent/DK144255C/en
Priority to CH1157773A priority patent/CH560434A5/xx
Priority to FR7329293A priority patent/FR2195813B3/fr
Priority to BE134448A priority patent/BE803464A/en
Priority to ES417739A priority patent/ES417739A1/en
Priority to DD172840A priority patent/DD107157A5/xx
Priority to SE7310965A priority patent/SE383793B/en
Priority to JP48089688A priority patent/JPS49132998A/ja
Priority to AT708673A priority patent/AT347300B/en
Publication of GB1405615A publication Critical patent/GB1405615A/en
Priority to HK553/76*UA priority patent/HK55376A/en
Priority to MY1976243A priority patent/MY7600243A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/103—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Abstract

1405615 Photo-detectore fire alarms CHUBB FIRE SECURITY Ltd 2 Aug 1973 [11 Aug 1972 14 Nov 1972] 37633/72 and 52587/72 Heading G1A [Also in Division G4] A fire alarm comprises a solid state source 10 emitting pulses of radiation, a detector 20 for receiving radiation passed through intervening gaseous medium, a frequency selective circuit 24 and an alarm circuit 28-36 responsive to an amplitude modulation present in the received signal and caused by variations in the refractive sides of the medium due to the heat of a fire. The photo-detector 20 has a standing bias applied to it or illumination by a subsidiary source to mimimize variations due to changes in the ambient light. The radiating source, e.g. a Gallium Arsenide diode is pulsed by about 1KHZ from devices 12, 14 and the frequency responsive circuit 24 is arranged to select a pulse signal having a frequency based on the rise time of the pulses of radiation. The effect of mains flicker is reduced in the above manner and the effect of other extraneous signals is reduced by emitting a pulsed instead of a continuous radiation. A further frequency responsive circuit 28, 30 is arranged to respond only to a band of modulation frequencies superimposed on the radiated pulses and caused by hot gases in the invervening medium. The output of the circuit 28, 30 is coupled to an alarm circuit 36 via a time delay 34 to prevent triggering by transient thermal phenomena. The arrangement also includes a circuit 38-48 which detects the presence of smoke by comparing at 40 the amplitude of signal detected during one period with the amplitude sampled and stored during the previous period. A further circuit 50-56 responds to a condition indicative of a fault or permanent obscuration of the radiated beam. An alarm circuit Fig. 6 (not shown), includes separate warning lamps associated with relays which become energized or de-energized to activate the above lamps. The source and detector may be kept at opposite ends of an enclosure or kept at the same end and associated with a reflecting mirror. Figs. 2-6 (not shown), relate to individual circuits usable in the arrangement of Fig. 1. The alarm may also operate as or incorporate a smoke detector.
GB3763372A 1972-08-11 1972-08-11 Fire alarms Expired GB1405615A (en)

Priority Applications (21)

Application Number Priority Date Filing Date Title
GB3763372A GB1405615A (en) 1972-08-11 1972-08-11 Fire alarms
US00385708A US3846772A (en) 1972-08-11 1973-08-06 Fire detector responsive to amplitude modulation of a pulsed em beam
NO3132/73A NO132564C (en) 1972-08-11 1973-08-06
ZA735343A ZA735343B (en) 1972-08-11 1973-08-06 Fire alarms
IL42930A IL42930A (en) 1972-08-11 1973-08-08 Fire alarms
DE2340041A DE2340041C2 (en) 1972-08-11 1973-08-08 Fire alarm device
AU59013/73A AU476368B2 (en) 1972-08-11 1973-08-08 Fire alarms
CA178,298A CA1010969A (en) 1972-08-11 1973-08-08 Fire alarms
IT51932/73A IT990203B (en) 1972-08-11 1973-08-09 FIRE DETECTION EQUIPMENT
NL7311010A NL7311010A (en) 1972-08-11 1973-08-09
CH1157773A CH560434A5 (en) 1972-08-11 1973-08-10
DK439773A DK144255C (en) 1972-08-11 1973-08-10 DEVICE FOR FIREFIGHT DETECTION
FR7329293A FR2195813B3 (en) 1972-08-11 1973-08-10
BE134448A BE803464A (en) 1972-08-11 1973-08-10 FIRE WARNING
ES417739A ES417739A1 (en) 1972-08-11 1973-08-10 Fire alarms
DD172840A DD107157A5 (en) 1972-08-11 1973-08-10
SE7310965A SE383793B (en) 1972-08-11 1973-08-10 FIRE DETECTOR, INCLUDING A RADIATION SOURCE AND A RADIATION RECEIVING BODY
JP48089688A JPS49132998A (en) 1972-08-11 1973-08-11
AT708673A AT347300B (en) 1972-08-11 1973-08-13 FIRE WARNING DEVICE
HK553/76*UA HK55376A (en) 1972-08-11 1976-09-08 Fire alarms
MY1976243A MY7600243A (en) 1972-08-11 1976-12-31 Fire alarms

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB3763372A GB1405615A (en) 1972-08-11 1972-08-11 Fire alarms
GB5258772 1972-11-14

Publications (1)

Publication Number Publication Date
GB1405615A true GB1405615A (en) 1975-09-10

Family

ID=26263518

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3763372A Expired GB1405615A (en) 1972-08-11 1972-08-11 Fire alarms

Country Status (17)

Country Link
JP (1) JPS49132998A (en)
AT (1) AT347300B (en)
AU (1) AU476368B2 (en)
CH (1) CH560434A5 (en)
DD (1) DD107157A5 (en)
DE (1) DE2340041C2 (en)
DK (1) DK144255C (en)
ES (1) ES417739A1 (en)
FR (1) FR2195813B3 (en)
GB (1) GB1405615A (en)
HK (1) HK55376A (en)
IL (1) IL42930A (en)
IT (1) IT990203B (en)
MY (1) MY7600243A (en)
NL (1) NL7311010A (en)
NO (1) NO132564C (en)
SE (1) SE383793B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2500552A1 (en) * 1981-02-24 1982-08-27 Fuji Heavy Ind Ltd DEVICE FOR DETECTING THE OVERHEAT OF A CLUTCH FOR AN INTERNAL COMBUSTION ENGINE
GB2161304A (en) * 1982-07-29 1986-01-08 Kerr Mc Gee Chem Corp Production monitoring system
DE102004004098B3 (en) * 2004-01-27 2005-09-01 Wagner Alarm- Und Sicherungssysteme Gmbh Method for evaluating a scattered light signal and scattered light detector for carrying out the method

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE7604502L (en) * 1976-04-15 1977-10-16 Ericsson Telefon Ab L M OPTICAL FIRE DETECTOR
SE395554B (en) * 1976-09-01 1977-08-15 Ericsson Telefon Ab L M OPTICAL FIRE DETECTOR
ATE4251T1 (en) * 1979-07-13 1983-08-15 Securiton Ag METHOD FOR DETECTING AEROSOLS IN AIR LOCATED IN A TEST ZONE AND EQUIPMENT FOR CARRYING OUT THE SAME.
JPS5631625A (en) * 1979-08-24 1981-03-31 Hochiki Corp Smoke detector of photoelectronic type
EP0145189B1 (en) * 1983-10-21 1990-08-08 COLE, Martin Terence Improvements relating to smoke detection apparatus
CN108510701B (en) * 2018-03-20 2019-11-22 深圳市泰和安科技有限公司 A kind of intelligent smog alarm method, apparatus and system

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE455987C (en) * 1924-04-11 1928-02-11 John Joseph Dowling Device for displaying light fluctuations through a light-sensitive cell and a highly sensitive relay
DE1024851B (en) * 1953-05-04 1958-02-20 Electronics Corp America Display device for flames
JPS4429154Y1 (en) * 1967-04-20 1969-12-03
GB1278205A (en) * 1970-02-11 1972-06-21 Shorrock Develpoments Ltd Smoke detecting device
DE2023463B1 (en) * 1970-05-13 1971-12-30 Preussag Ag Feuerschutz Optical smoke detector

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2500552A1 (en) * 1981-02-24 1982-08-27 Fuji Heavy Ind Ltd DEVICE FOR DETECTING THE OVERHEAT OF A CLUTCH FOR AN INTERNAL COMBUSTION ENGINE
GB2161304A (en) * 1982-07-29 1986-01-08 Kerr Mc Gee Chem Corp Production monitoring system
DE102004004098B3 (en) * 2004-01-27 2005-09-01 Wagner Alarm- Und Sicherungssysteme Gmbh Method for evaluating a scattered light signal and scattered light detector for carrying out the method
US7440100B2 (en) 2004-01-27 2008-10-21 Wagner Alarm Sicherungssysteme Gmbh Method for evaluation of a scattered light signal and scattered light detector used for carrying out said method

Also Published As

Publication number Publication date
DK144255C (en) 1982-08-16
DE2340041A1 (en) 1974-04-04
IL42930A0 (en) 1973-11-28
IT990203B (en) 1975-06-20
NL7311010A (en) 1974-02-13
ATA708673A (en) 1978-04-15
FR2195813B3 (en) 1975-10-31
NO132564B (en) 1975-08-18
CH560434A5 (en) 1975-03-27
MY7600243A (en) 1976-12-31
FR2195813A1 (en) 1974-03-08
SE383793B (en) 1976-03-29
AU476368B2 (en) 1976-09-16
DD107157A5 (en) 1974-07-12
AU5901373A (en) 1975-02-13
ES417739A1 (en) 1976-02-16
AT347300B (en) 1978-12-27
NO132564C (en) 1975-11-26
DK144255B (en) 1982-01-25
DE2340041C2 (en) 1984-11-29
IL42930A (en) 1976-10-31
HK55376A (en) 1976-09-17
JPS49132998A (en) 1974-12-20

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PE20 Patent expired after termination of 20 years

Effective date: 19930801