GB1529473A - Photo-responsive detectors - Google Patents

Photo-responsive detectors

Info

Publication number
GB1529473A
GB1529473A GB48613/75A GB4861375A GB1529473A GB 1529473 A GB1529473 A GB 1529473A GB 48613/75 A GB48613/75 A GB 48613/75A GB 4861375 A GB4861375 A GB 4861375A GB 1529473 A GB1529473 A GB 1529473A
Authority
GB
United Kingdom
Prior art keywords
resistance
equal
light
smoke
photo
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
GB48613/75A
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.)
CHLORIDE BATTERIJEN BV
Original Assignee
CHLORIDE BATTERIJEN BV
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 US05/621,085 external-priority patent/US4011458A/en
Application filed by CHLORIDE BATTERIJEN BV filed Critical CHLORIDE BATTERIJEN BV
Publication of GB1529473A publication Critical patent/GB1529473A/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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • 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
    • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
    • G08B17/113—Constructional details

Landscapes

  • Analytical Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Emergency Alarm Devices (AREA)

Abstract

1529473 Smoke detectors CHLORIDE BATTERIJEN BV 26 Nov 1975 [27 Nov 1974 9 Oct 1975] 48613/75 Heading G1A A detector Fig. 2 comprises: first and second photo-resistive cells C1, C3 placed to receive light originating at a source 18, the first cell C1 only after reflection by a test medium; means R1, A1 responsive to a decrease in resistance of C1 to a predetermined resistance to actuate, SCR, a signalling device A; and control means R2, A2, T1 responsive to a change in the resistance of C3 to adjust the source 18 to an intensity at which C3 is continuously exposed to that intensity which causes its thermal resistance coefficient to be substantially equal to that of Cl when exposed to the light intensity at which its resistance is equal to the predetermined value. In a smoke detector Fig. 1 a block 10 houses a LED 18 directing a beam via a lens 20 through a first aperture 12, and a first photo-resistive cell C1 viewing, via a lens 22 and aperture 14, light forward-scattered by any smoke in the beam. A second photo-resistive cell C3 in the block 10 receives, via a light guide 24, light in the beam path which may have been attenuated by the smoke. A manual screw 26 regulates the amount of light received by C3. A further photosensor C2 monitors the source 18 to actuate a warning lamp L, Fig. 2 in case of failure. The cells C1, C3, Fig. 2, having matched characteristics and temperature coefficients, are connected in series with respective equal resistances R1, R2, the junction points Jl, J2 each being connected to an amplifier A1, A2 arranged to change its output state when its input crosses a potential equal to half the supply voltage. The first amplifier A1 is connected to trigger a SCR actuating an audible warning device A. The second amplifier A2 controls the LED 18 so that the light received by C3 is just sufficient to maintain its resistance equal to R2 and therefore equal to the resistance which Cl will have at the alarm point. The arrangement is especially advantageous in maintaining the sensitivity and accuracy of the detector in the presence of black smoke having high attenuation and poor reflectivity.
GB48613/75A 1974-11-27 1975-11-26 Photo-responsive detectors Expired GB1529473A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US52758974A 1974-11-27 1974-11-27
US05/621,085 US4011458A (en) 1975-10-09 1975-10-09 Photoelectric detector with light source intensity regulation

Publications (1)

Publication Number Publication Date
GB1529473A true GB1529473A (en) 1978-10-18

Family

ID=27062456

Family Applications (1)

Application Number Title Priority Date Filing Date
GB48613/75A Expired GB1529473A (en) 1974-11-27 1975-11-26 Photo-responsive detectors

Country Status (10)

Country Link
JP (1) JPS5624898B2 (en)
AU (1) AU497359B2 (en)
BR (1) BR7507896A (en)
CA (1) CA1052887A (en)
CH (1) CH604299A5 (en)
DE (1) DE2553339A1 (en)
FR (1) FR2292975A1 (en)
GB (1) GB1529473A (en)
IT (1) IT1054912B (en)
SE (1) SE406657B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2230853A (en) * 1989-03-23 1990-10-31 Nittan Co Ltd Photoelectric smoke sensor
US7709774B2 (en) 2005-10-19 2010-05-04 Koninklijke Philips Electronics N.V. Color lighting device

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53102085A (en) * 1977-02-18 1978-09-06 Mochida Pharm Co Ltd Instrument for measuring amount of bilirubin
DE2965650D1 (en) * 1979-02-01 1983-07-21 Bbc Brown Boveri & Cie Photoelectric system for monitoring flames and fumes
US4306230A (en) * 1979-12-10 1981-12-15 Honeywell Inc. Self-checking photoelectric smoke detector

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1164793A (en) * 1966-04-05 1969-09-24 Photain Controls Ltd Photo-electric Detection Devices
US3461443A (en) * 1966-11-07 1969-08-12 Alfred W Vasel Smoke detector with means indicating the failure of the light source
GB1222351A (en) * 1966-12-07 1971-02-10 Derek Charles Adams Improvements in or relating to fire-detection apparatus
GB1278205A (en) * 1970-02-11 1972-06-21 Shorrock Develpoments Ltd Smoke detecting device
US3736431A (en) * 1971-04-30 1973-05-29 Mobil Oil Corp System for monitoring a fluid stream

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2230853A (en) * 1989-03-23 1990-10-31 Nittan Co Ltd Photoelectric smoke sensor
GB2230853B (en) * 1989-03-23 1993-03-17 Nittan Co Ltd Photoelectric smoke sensor
US7709774B2 (en) 2005-10-19 2010-05-04 Koninklijke Philips Electronics N.V. Color lighting device

Also Published As

Publication number Publication date
AU497359B2 (en) 1978-12-07
AU8670575A (en) 1977-05-26
JPS5624898B2 (en) 1981-06-09
CA1052887A (en) 1979-04-17
SE7513301L (en) 1976-05-28
FR2292975B1 (en) 1981-09-18
CH604299A5 (en) 1978-09-15
BR7507896A (en) 1976-08-10
JPS5177386A (en) 1976-07-05
DE2553339A1 (en) 1976-08-12
SE406657B (en) 1979-02-19
IT1054912B (en) 1981-11-30
FR2292975A1 (en) 1976-06-25

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee