GB1356605A - Fire detector apparatus - Google Patents

Fire detector apparatus

Info

Publication number
GB1356605A
GB1356605A GB4754771A GB4754771A GB1356605A GB 1356605 A GB1356605 A GB 1356605A GB 4754771 A GB4754771 A GB 4754771A GB 4754771 A GB4754771 A GB 4754771A GB 1356605 A GB1356605 A GB 1356605A
Authority
GB
United Kingdom
Prior art keywords
ionization
detector
oct
radio frequency
fire alarm
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
GB4754771A
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.)
Edwards Co Inc
Original Assignee
Edwards Co Inc
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 Edwards Co Inc filed Critical Edwards Co Inc
Publication of GB1356605A publication Critical patent/GB1356605A/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

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 Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

1356605 Ionization fire alarm systems EDWARDS CO Inc 12 Oct 1971 [12 Oct 1970] 47547/71 Heading GIN In a fire alarm including an ionization chamber smoke detector 11 and a semi-conductor device 12 responsive to the output of the detector 11, the ionization in the detector 11 and the response of the device 12 are stabilized by superimposing a radio frequency alternating voltage on the D. C. power supply. As shown, detector 11 includes measuring and reference ionization chambers M and R including radio-active sources and connected in series. The voltage at their junction is applied to the gate electrode of a F. E . T. Capacitors C and resistors R together with the interelectrode capacitances of the ionization chambers and the junction capacitance of the F. E. T. are tuned to the applied radio frequency which is preferably at least 2 MHz. The amplitude of the R. F. is equal to or slightly higher than a D. C. ionizing potential for the sensing means and less than the bias level of the F.E.T.
GB4754771A 1970-10-12 1971-10-12 Fire detector apparatus Expired GB1356605A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US7997270A 1970-10-12 1970-10-12

Publications (1)

Publication Number Publication Date
GB1356605A true GB1356605A (en) 1974-06-12

Family

ID=22153980

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4754771A Expired GB1356605A (en) 1970-10-12 1971-10-12 Fire detector apparatus

Country Status (3)

Country Link
US (1) US3728703A (en)
CA (1) CA929683A (en)
GB (1) GB1356605A (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4023152A (en) * 1973-10-01 1977-05-10 Matsushita Electric Works, Ltd. Ionization type smoke sensing device
JPS51100085U (en) * 1975-02-10 1976-08-11
US4104619A (en) * 1976-10-01 1978-08-01 General Electric Company Smoke detector
US4118689A (en) * 1976-12-01 1978-10-03 General Electric Company Smoke detector
US4222046A (en) * 1978-07-31 1980-09-09 Honeywell Inc. Abnormal condition responsive means with periodic high sensitivity
WO2020251733A1 (en) * 2019-06-14 2020-12-17 Carrier Corporation Smoke and steam detector

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE564961A (en) * 1957-02-19
US3018376A (en) * 1957-11-29 1962-01-23 Nat Res Corp Gas density measurement
DK101900C (en) * 1961-12-30 1965-06-08 Danske Securitas As Electrical alarm system, preferably for fire alarm.
CH473431A (en) * 1966-05-09 1969-05-31 Cerberus Ag Werk Fuer Elektron Procedure for monitoring the operation of fire alarms

Also Published As

Publication number Publication date
CA929683A (en) 1973-07-03
US3728703A (en) 1973-04-17

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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