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GB1394642A - Electrical alarm instruments - Google Patents

Electrical alarm instruments

Info

Publication number
GB1394642A
GB1394642A GB1052773A GB1052773A GB1394642A GB 1394642 A GB1394642 A GB 1394642A GB 1052773 A GB1052773 A GB 1052773A GB 1052773 A GB1052773 A GB 1052773A GB 1394642 A GB1394642 A GB 1394642A
Authority
GB
United Kingdom
Prior art keywords
horn
mode
inductance
energized
relay
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
GB1052773A
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.)
Electro Signal Lab Inc
Original Assignee
Electro Signal Lab 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 Electro Signal Lab Inc filed Critical Electro Signal Lab Inc
Publication of GB1394642A publication Critical patent/GB1394642A/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
    • G08B17/103—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device
    • G08B17/107—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device for detecting light-scattering due to smoke

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 Analysing Materials By Optical Means (AREA)
  • Emergency Alarm Devices (AREA)

Abstract

1394642 Smoke detectors ELECTRO SIGNAL LAB Inc 5 March 1973 [15 March 1972] 10527/73 Heading G1A [Also in Division G4] An alarm instrument for sensing a physical condition includes an alarm device, e.g. horn H, which operates in a first mode in response to a predetermined change in the physical condition, and in a second mode in a response to a circuit fault. The second mode is initiated by a pulse generator. As described, the instrument is a smoke detector, having a lamp DS-1 and photo-cells PC-1, PC-2 energized by an unsmoothed half wave rectified A.C. power supply. Pressure of smoke reduces the resistance of cell PC-1 until the potential at point 3 rises sufficiently for neon NE-1 to strike and trigger SCR Q2. Relay K in series with lamp DS-1 is energized to hold its contact in the K1 position, and horn H is energized, via SCR Q2, its inductance being sufficient to maintain current through it throughout. The whole cycle of the power supply input. A rise in temperature closes thermostatic switch TH to similarly trigger SCR Q2. If the lamp DS-1 fails, relay K releases, and its contact moves to the K' position to energize relaxation circuit R7, Cl NE-2 via the horn inductance, and to shunt the horn inductance by diode D5. In this mode the horn current is not maintained throughout the whole cycle and the horn is pulsed at a rate dependent on the time constants of the relaxation circuit. In a modification, Fig. 2 (not shown). The relay K and its contacts are replaced by a transistor circuit.
GB1052773A 1972-03-15 1973-03-05 Electrical alarm instruments Expired GB1394642A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US23477572A 1972-03-15 1972-03-15

Publications (1)

Publication Number Publication Date
GB1394642A true GB1394642A (en) 1975-05-21

Family

ID=22882779

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1052773A Expired GB1394642A (en) 1972-03-15 1973-03-05 Electrical alarm instruments

Country Status (4)

Country Link
US (1) US3774186A (en)
CA (1) CA981754A (en)
DE (1) DE2312977A1 (en)
GB (1) GB1394642A (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3936814A (en) * 1974-04-29 1976-02-03 Bernz-O-Matic Corporation Smoke detector and alarm
US3879717A (en) * 1974-06-19 1975-04-22 K F Ind Inc Portable methane monitor and alarm system
US4001800A (en) * 1974-06-24 1977-01-04 Gentex Company Smoke detecting device
US3980997A (en) * 1974-07-17 1976-09-14 General Signal Corporation Smoke detector
US4021792A (en) * 1975-06-23 1977-05-03 Wellen Industries Smoke alarm
US4283657A (en) * 1976-03-25 1981-08-11 Lampiridae Associates Exit illuminating system
US4096473A (en) * 1976-12-09 1978-06-20 P.R. Mallory & Co. Inc. High output smoke and heat detector alarm system utilizing a piezoelectric transducer and a voltage doubling means
US4093943A (en) * 1976-12-27 1978-06-06 Knight Webster B Sequential power distribution circuit
US4101880A (en) * 1976-12-27 1978-07-18 Wheelock Signals, Inc. Audiovisual signaling device
US4302753A (en) * 1978-01-26 1981-11-24 Pittway Corporation Multi-function combustion detecting device
USRE30620E (en) * 1978-07-03 1981-05-19 P. R. Mallory & Co. Inc. High output smoke and heat detector alarm system utilizing a piezoelectric transducer and a voltage doubling means
US4266220A (en) * 1979-07-27 1981-05-05 Malinowski William J Self-calibrating smoke detector and method
US4471346A (en) * 1981-06-02 1984-09-11 Eberhard Faber, Inc. Smoke detector

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1290819B (en) * 1963-09-05 1969-03-13 Kalle Ag Device for wetting development of electrophotographic recording material
US3487404A (en) * 1967-03-23 1969-12-30 Avco Corp Combined fire alarm,burglar alarm,and intercommunication system
US3555532A (en) * 1968-10-29 1971-01-12 Graham Stuart Corp Vapor or particle detection device
US3693110A (en) * 1971-02-23 1972-09-19 C A Briggs Co Audible signal or alarm device including two variable frequency unijunction transistor oscillators

Also Published As

Publication number Publication date
CA981754A (en) 1976-01-13
DE2312977A1 (en) 1973-09-27
US3774186A (en) 1973-11-20

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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