EP 0030621 B1 19850116 - IONISATION SMOKE SIGNALLER WITH PARTICULAR OPERATIONAL RELIABILITY
Title (en)
IONISATION SMOKE SIGNALLER WITH PARTICULAR OPERATIONAL RELIABILITY
Publication
Application
Priority
CH 1107779 A 19791214
Abstract (en)
[origin: US4364031A] An ionization smoke detector containing at least one ionization chamber operated at an extra low voltage or potential. The ionization chamber contains a sensor employing a measuring electrode and a counter electrode. Ambient air has practically free access to the ionization chamber and there are provided one or more radioactive sources for generating ions, a supply voltage source and an electrical circuit for triggering an alarm. The smoke detector possesses increased operational reliability since circuit elements are provided which enable signal reporting to a central station by means of a low-voltage of about 200 volts, however the sensor is operated at an extra low voltage.
IPC 1-7
IPC 8 full level
G01N 27/64 (2006.01); G08B 17/10 (2006.01); G08B 17/11 (2006.01)
CPC (source: EP US)
G08B 17/11 (2013.01 - EP US)
Citation (examination)
- US 3295121 A 19661227 - SCHEEL MEYER SVEND
- US 3872449 A 19750318 - SCHEIDWEILER ANDREAS
- FR 2299879 A1 19760903 - HOCHIKI CO [JP]
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0030621 A1 19810624; EP 0030621 B1 19850116; AT E11345 T1 19850215; CA 1148279 A 19830614; DE 3069987 D1 19850228; JP S5694497 A 19810730; JP S6242320 B2 19870908; US 4364031 A 19821214; YU 314380 A 19831031
DOCDB simple family (application)
EP 80106923 A 19801110; AT 80106923 T 19801110; CA 361830 A 19801008; DE 3069987 T 19801110; JP 17390980 A 19801211; US 19880780 A 19801020; YU 314380 A 19801212