GB1009271A - Improvements in or relating to smoke detector circuits - Google Patents

Improvements in or relating to smoke detector circuits

Info

Publication number
GB1009271A
GB1009271A GB8549/63A GB854963A GB1009271A GB 1009271 A GB1009271 A GB 1009271A GB 8549/63 A GB8549/63 A GB 8549/63A GB 854963 A GB854963 A GB 854963A GB 1009271 A GB1009271 A GB 1009271A
Authority
GB
United Kingdom
Prior art keywords
point
transistor
responsive
source
smoke
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
GB8549/63A
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.)
ASSOCIATED FIRE ALARMS Ltd
Original Assignee
ASSOCIATED FIRE ALARMS 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 ASSOCIATED FIRE ALARMS Ltd filed Critical ASSOCIATED FIRE ALARMS Ltd
Priority to GB8549/63A priority Critical patent/GB1009271A/en
Publication of GB1009271A publication Critical patent/GB1009271A/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
    • G08B17/11—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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biochemistry (AREA)
  • Electrochemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Fire-Detection Mechanisms (AREA)

Abstract

1,009,271. Semi-conductor circuit. ASSOCIATED FIRE ALARMS Ltd., and B.J.L. WHITE. March 2, 1964 [March 4, 1963], No. 8549/63, Heading H3T. [Also in Division G1] The voltage at a point 17 between an ionization gauge 10 responsive to the amount of smoke in the atmosphere, and a resistor 11, which may be a second ionization chamber closed to the atmosphere, is applied to the modulator of a field effect transistor 14 fed from an LT source 16, and when as a result of smoke the voltage drops below that at point 18 current through transistor 14 ceases and point 20 which is set to become positive with respect to point 19 eventually renders transistors TR1 and TR2 conductive, diode D3 making the arrangement bi-stable. The larger current drawn from the source by the transistors actuates a relay in the supply lead. Capacitor C ensures that transistor TR1 does not conduct immediately on reset. A number of such circuits may be connected to a single LT power source, and the relay may be responsive to the total current drawn. Transistor 14 may be coupled to point 17 by a capacitor to make the circuit responsive only to rapid changes. Component values are exemplified.
GB8549/63A 1963-03-04 1963-03-04 Improvements in or relating to smoke detector circuits Expired GB1009271A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8549/63A GB1009271A (en) 1963-03-04 1963-03-04 Improvements in or relating to smoke detector circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8549/63A GB1009271A (en) 1963-03-04 1963-03-04 Improvements in or relating to smoke detector circuits

Publications (1)

Publication Number Publication Date
GB1009271A true GB1009271A (en) 1965-11-10

Family

ID=9854595

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8549/63A Expired GB1009271A (en) 1963-03-04 1963-03-04 Improvements in or relating to smoke detector circuits

Country Status (1)

Country Link
GB (1) GB1009271A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521263A (en) * 1966-02-22 1970-07-21 Cerberus Ag Ionization fire alarm and improved method of detecting smoke and combustion aerosols
US3543056A (en) * 1967-08-07 1970-11-24 Johnson Service Co Proximity detection system using field effect transistors
GB2138570A (en) * 1983-04-19 1984-10-24 Emi Ltd Smoke detector
CN102426751A (en) * 2011-08-26 2012-04-25 无锡蓝天电子有限公司 Point-type photoelectric smoke detector

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521263A (en) * 1966-02-22 1970-07-21 Cerberus Ag Ionization fire alarm and improved method of detecting smoke and combustion aerosols
US3543056A (en) * 1967-08-07 1970-11-24 Johnson Service Co Proximity detection system using field effect transistors
GB2138570A (en) * 1983-04-19 1984-10-24 Emi Ltd Smoke detector
CN102426751A (en) * 2011-08-26 2012-04-25 无锡蓝天电子有限公司 Point-type photoelectric smoke detector
CN102426751B (en) * 2011-08-26 2013-07-17 无锡蓝天电子有限公司 Point-type photoelectric smoke detector

Similar Documents

Publication Publication Date Title
GB1230206A (en)
GB978057A (en) Thermoelectric circuits
US3240997A (en) Power supply
GB1009271A (en) Improvements in or relating to smoke detector circuits
GB1257318A (en)
SE328226B (en)
GB1249442A (en) Collector follower-type transistorized voltage regulator
GB1221866A (en) Time delay circuit
GB819627A (en) Improvements in or relating to transistor circuit arrangements for d.c. voltage stabilisation
GB1126951A (en) A voltage regulated supply circuit
GB1261096A (en) Flame monitoring fuel control device
GB1052790A (en)
GB1524558A (en) Input circuits
GB940784A (en) Improvements in or relating to voltage regulator circuits
GB1047524A (en) Improvements in circuits for energising current or voltage responsive devices
GB997020A (en) Improvements in or relating to electric timing circuits
GB1011188A (en) Improvements in or relating to voltage stabilisers
GB992661A (en) Improvements of and relating to transistorized control circuits
GB1038086A (en) Improvements relating to photosensitive apparatus
GB1110037A (en) Short-circuit-proof transistor stabilization circuit arrangement
GB1031464A (en) Pulse generators
GB1099014A (en) Improvements in or relating to electrical pulse-stabilising circuits
GB1058160A (en) Improved voltage stabilizer circuit arrangements
GB968475A (en) Improvements in or relating to transistor amplifier circuits
GB1016507A (en) Circuit arrangement for regulating the output voltage of a dynamotor