GB949651A - Improvements in or relating to photo-electric indicator circuits - Google Patents

Improvements in or relating to photo-electric indicator circuits

Info

Publication number
GB949651A
GB949651A GB4627561A GB4627561A GB949651A GB 949651 A GB949651 A GB 949651A GB 4627561 A GB4627561 A GB 4627561A GB 4627561 A GB4627561 A GB 4627561A GB 949651 A GB949651 A GB 949651A
Authority
GB
United Kingdom
Prior art keywords
photo
lamp
cell
illuminated
indicator
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
GB4627561A
Inventor
John Wilson
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.)
Pyrene Co Ltd
Original Assignee
Pyrene Co Ltd
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 Pyrene Co Ltd filed Critical Pyrene Co Ltd
Priority to GB4627561A priority Critical patent/GB949651A/en
Publication of GB949651A publication Critical patent/GB949651A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/941—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated using an optical detector
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V8/00—Prospecting or detecting by optical means
    • G01V8/10—Detecting, e.g. by using light barriers
    • G01V8/20—Detecting, e.g. by using light barriers using multiple transmitters or receivers
    • 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
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
    • G08B29/12—Checking intermittently signalling or alarm systems
    • G08B29/14—Checking intermittently signalling or alarm systems checking the detection circuits

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geophysics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

949,651. Photo-electric detector circuits. PYRENE CO. Ltd. Dec. 18,1962 [Dec.27, 1961], No. 46275/61. Heading G1A. [Also in Divisions G4 and H3] A photo-electric detector circuit comprises a photo-electric device 4, a lamp 1 which will cause illumination of the device 4 when a condition such as the presence of smoke in a tube prevails, means for providing a test illumination of the device 4, indicator means 24 operated by the device 4 when it is illuminated and means for re-setting the indicator means to an unoperated condition, and means for maintaining the indicator means in an operated condition once the photo-electric device has been illuminated, in combination with means responsive to the operation of the indicator means to suppress simultaneously the illumination of the photo-electric device. In the embodiment shown the invention is used in a smoke detector system of the kind where a lamp 1 and a photocell 4 are arranged on opposite sides of a chamber (not shown) with a mask 5 between them so that the photo-cell is only illuminated when smoke is present in the tube, by light diffused by the smoke and a further lamp 6 is provided to enable the photo-cell to be illuminated directly, for test purposes. When the photo-cell 4 is illuminated its drop in resistance causes the output signal from an amplifier 8 formed by transistors 9, 10, 16, 21 to energize a relay RL/2 which closes a contact RL1 to light an indicator lamp 24 and opens a contact RL2 thus disconnecting both lamps 1 and 6 from a supply line 3. Opening of the contact RL2 introduces a resistor 26 into the potential divider formed by a resistor 25 and the photo-cell 4 with the effect that the base of the transistor 9 is kept sufficiently negative with respect to its emitter to hold the amplifier in the condition where the relay RL/2 is kept energized. The indicator lamp 24 can then only be switched off by moving a switch SW1 to a RESET position whereby the base of the transistor 16 is earthed causing the relay RL/2 to be de-energized. If the filament of the lamp 1 is broken then the indicator lamp 24 is extinguished immediately on release of the test switch SW1 from the TEST position because without the filament in parallel with resistor 25 and the photo-cell 4 the input voltage to the amplifier 8 is insufficiently negative to keep the relay energized. A temperature sensitive element 13 is included in the amplifier circuit 8 to stabilize the operation of the arrangement against variations of output across a load resistor 15 with temperature changes. The test lamp 6 may be replaced by a solenoid operating a reflector flap which reflects light from the primary lamp 1 on to the photo-cell 4.
GB4627561A 1961-12-27 1961-12-27 Improvements in or relating to photo-electric indicator circuits Expired GB949651A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4627561A GB949651A (en) 1961-12-27 1961-12-27 Improvements in or relating to photo-electric indicator circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4627561A GB949651A (en) 1961-12-27 1961-12-27 Improvements in or relating to photo-electric indicator circuits

Publications (1)

Publication Number Publication Date
GB949651A true GB949651A (en) 1964-02-19

Family

ID=10440571

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4627561A Expired GB949651A (en) 1961-12-27 1961-12-27 Improvements in or relating to photo-electric indicator circuits

Country Status (1)

Country Link
GB (1) GB949651A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0113461A2 (en) * 1982-12-14 1984-07-18 Nohmi Bosai Kogyo Co., Ltd. Functional test means of light scattering type smoke detector
GB2157468A (en) * 1984-04-11 1985-10-23 Wang Chun Jong A method and device for detection of a blanket or the like being kicked off the body of a sleeping person

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0113461A2 (en) * 1982-12-14 1984-07-18 Nohmi Bosai Kogyo Co., Ltd. Functional test means of light scattering type smoke detector
EP0113461A3 (en) * 1982-12-14 1986-10-01 Nohmi Bosai Kogyo Co., Ltd. Functional test means of light scattering type smoke detector
GB2157468A (en) * 1984-04-11 1985-10-23 Wang Chun Jong A method and device for detection of a blanket or the like being kicked off the body of a sleeping person

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