GB637207A - Improvements relating to alarm or indicating systems employing photoeletcric cells - Google Patents

Improvements relating to alarm or indicating systems employing photoeletcric cells

Info

Publication number
GB637207A
GB637207A GB3251947A GB3251947A GB637207A GB 637207 A GB637207 A GB 637207A GB 3251947 A GB3251947 A GB 3251947A GB 3251947 A GB3251947 A GB 3251947A GB 637207 A GB637207 A GB 637207A
Authority
GB
United Kingdom
Prior art keywords
alarm
photoeletcric
cells
relay
improvements relating
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
GB3251947A
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.)
Ronald Trist and Co Ltd
Original Assignee
Ronald Trist and 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 Ronald Trist and Co Ltd filed Critical Ronald Trist and Co Ltd
Priority to GB3251947A priority Critical patent/GB637207A/en
Publication of GB637207A publication Critical patent/GB637207A/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
    • G08B17/12—Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions

Landscapes

  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Apparatus For Disinfection Or Sterilisation (AREA)

Abstract

637,207. Valve relay circuits. TRIST & CO., Ltd., R., and CHAMBERS, W. A. Dec. 9, 1947, No. 32519. [Class 40 (vi)] [Also in Group XL (b)] A capactitor 11, charged from a source 14 over a high resistor 13, discharges through a relay 12 when an associated valve 8 is rendered conductive. The relay is maintained operated by a bias circuit from source 16 over resistor 17, an alarm circuit being completed over contacts 19, and reset by button 21. The valve 8 is preferably of the cold cathode type and is fired by a negative potential on the grid as described in Specification 636,341, 'when the photo-electric cell 1 is illuminated less than cell 2. Specification 521,621 also is referred to.
GB3251947A 1947-12-09 1947-12-09 Improvements relating to alarm or indicating systems employing photoeletcric cells Expired GB637207A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3251947A GB637207A (en) 1947-12-09 1947-12-09 Improvements relating to alarm or indicating systems employing photoeletcric cells

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3251947A GB637207A (en) 1947-12-09 1947-12-09 Improvements relating to alarm or indicating systems employing photoeletcric cells

Publications (1)

Publication Number Publication Date
GB637207A true GB637207A (en) 1950-05-17

Family

ID=10339849

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3251947A Expired GB637207A (en) 1947-12-09 1947-12-09 Improvements relating to alarm or indicating systems employing photoeletcric cells

Country Status (1)

Country Link
GB (1) GB637207A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1005877B (en) * 1953-02-14 1957-04-04 Ericsson Telefon Ab L M Automatic fire alarm system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1005877B (en) * 1953-02-14 1957-04-04 Ericsson Telefon Ab L M Automatic fire alarm system

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