GB1512545A - Ionisation fire sensors - Google Patents

Ionisation fire sensors

Info

Publication number
GB1512545A
GB1512545A GB38981/75A GB3898175A GB1512545A GB 1512545 A GB1512545 A GB 1512545A GB 38981/75 A GB38981/75 A GB 38981/75A GB 3898175 A GB3898175 A GB 3898175A GB 1512545 A GB1512545 A GB 1512545A
Authority
GB
United Kingdom
Prior art keywords
small
gate
sept
variable resistance
voltage
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
GB38981/75A
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.)
Cerberus AG
Original Assignee
Cerberus AG
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 Cerberus AG filed Critical Cerberus AG
Publication of GB1512545A publication Critical patent/GB1512545A/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

Abstract

1512545 Smoke detectors CERBERUS AG 23 Sept 1975 [23 Sept 1974] 38981/75 Heading G1N A fire sensor includes two series-connected ionization chambers 1, 2 the junction point of which is connected to the gate 6a of F.E.T. 6 the source voltage of which is set by a Zener diode 12 in the source return lead to terminal 4, and the gate voltage of which is adjustable by variable resistance 15 which together with resistor 14 forms a voltage divider across terminals 3, 4. In the quiescent condition power consumption is small since current flow through the F.E.T. and Zener diode is small whilst allowing sufficiently large current to be drawn, in an alarm condition, to trigger the S.C.R.11 due to the Zener characteristic. The gate potential adjustment by variable resistance 15 allows adjustment of the sensitivity or changeover point but the resistances 14, 15 are of high value so as to draw only a small current.
GB38981/75A 1974-09-23 1975-09-23 Ionisation fire sensors Expired GB1512545A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1284374A CH569335A5 (en) 1974-09-23 1974-09-23

Publications (1)

Publication Number Publication Date
GB1512545A true GB1512545A (en) 1978-06-01

Family

ID=4386908

Family Applications (1)

Application Number Title Priority Date Filing Date
GB38981/75A Expired GB1512545A (en) 1974-09-23 1975-09-23 Ionisation fire sensors

Country Status (7)

Country Link
CH (1) CH569335A5 (en)
DE (1) DE2541290A1 (en)
DK (1) DK135648B (en)
FR (1) FR2285666A1 (en)
GB (1) GB1512545A (en)
NO (1) NO140081C (en)
SE (1) SE405520B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2713280C3 (en) * 1977-03-25 1986-10-23 Esser Sicherheitstechnik GmbH & Co KG, 4040 Neuss Function-testable fire alarm system
DE102014019172B4 (en) 2014-12-17 2023-12-07 Elmos Semiconductor Se Device and method for distinguishing between solid objects, cooking fumes and smoke using a compensating optical measuring system
DE102014019773B4 (en) 2014-12-17 2023-12-07 Elmos Semiconductor Se Device and method for distinguishing between solid objects, cooking fumes and smoke using the display of a mobile telephone

Also Published As

Publication number Publication date
DK135648C (en) 1977-11-07
FR2285666A1 (en) 1976-04-16
DK424375A (en) 1976-03-24
DK135648B (en) 1977-05-31
NO140081C (en) 1979-07-04
SE405520B (en) 1978-12-11
CH569335A5 (en) 1975-11-14
DE2541290A1 (en) 1976-04-08
FR2285666B1 (en) 1982-04-23
SE7510476L (en) 1976-03-24
NO140081B (en) 1979-03-19
NO753217L (en) 1976-03-24

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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