(19)
(11) EP 1 006 500 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
11.04.2001 Bulletin 2001/15

(43) Date of publication A2:
07.06.2000 Bulletin 2000/23

(21) Application number: 99309678.3

(22) Date of filing: 02.12.1999
(51) International Patent Classification (IPC)7G08B 17/10
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 04.12.1998 US 205440

(71) Applicant: PITTWAY CORPORATION
Chicago, Illinois 60606 (US)

(72) Inventors:
  • Schoenfelder, George A.
    Batavia, Illinois 60510 (US)
  • Shoaff, Thomas
    Warrenville, Illinois 60555 (US)
  • Daly, Juliette C.
    Chicago, Illinois 60601 (US)
  • Gonzales, Eric V.
    Aurora, Illinois 60504 (US)

(74) Representative: Vigars, Christopher Ian et al
Haseltine Lake & Co., Imperial House, 15-19 Kingsway
London WC2B 6UD
London WC2B 6UD (GB)

   


(54) Smoke detector with aspiration unit and flow sensor


(57) A detector includes a smoke sensor and an aspiration unit. The aspiration unit causes ambient air from a region directly adjacent to the detector to flow into a sensing region of the sensor. A flow monitoring sensor provides feedback to a control circuit to vary pulse modulated drive signals coupled to the aspiration unit. A plurality of variable resistance temperature sensors can be used for flow monitoring. Communication with the detector can be carried out via interface circuits.







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