GB1038304A - Warning apparatus - Google Patents

Warning apparatus

Info

Publication number
GB1038304A
GB1038304A GB3255064A GB3255064A GB1038304A GB 1038304 A GB1038304 A GB 1038304A GB 3255064 A GB3255064 A GB 3255064A GB 3255064 A GB3255064 A GB 3255064A GB 1038304 A GB1038304 A GB 1038304A
Authority
GB
United Kingdom
Prior art keywords
transistor
oscillator
switching
rectifier
output
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
GB3255064A
Inventor
John Charles Edward Taylor
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.)
Sperry Gyroscope Co Ltd
Original Assignee
Sperry Gyroscope 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 Sperry Gyroscope Co Ltd filed Critical Sperry Gyroscope Co Ltd
Priority to GB3255064A priority Critical patent/GB1038304A/en
Publication of GB1038304A publication Critical patent/GB1038304A/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
    • G08B17/117—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means by using a detection device for specific gases, e.g. combustion products, produced by the fire

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Gyroscopes (AREA)

Abstract

1,038,304. Transistor switching circuits. SPERRY GYROSCOPE CO. Ltd. Sept. 8, 1965 [Aug. 10, 1964], No. 32550/64. Heading H3T. [Also in Division G4] A warning device comprises an oscillator and a loud-speaker arranged to given an audible warning, and a time delay circuit which energizes a pilot circuit at a predetermined time after the audible warning commences. The arrangement is suitable for use in the presence of inflammable gases, being arranged to operate from a low voltage, and being enclosed in a flame-proof casing. Completion of a low voltage 50 c/s. supply circuit to terminals 1, 2 produces a partially smoothed D.C. output from rectifier 3 which energizes an oscillator comprising transistors 6, 7 and saturable transformer 8 to produce a square-wave output signal modulated with the unsmoothed ripple component. The impedance of the supply connected to rectifier 3 is made high by resistor 4 and the load on the supply due to the oscillator causes the D.C. output from rectifier 3 to be about 8 v. Capacitor 19 charges towards this value until the Zener voltage of diode 20 is overcome and transistor 21 switches on, switching off transistor 23, and switching on transistor 26 to apply a voltage to a pilot circuit connected to terminals 27, 28. Upon transistor 21 becoming conductive transistor 12 also cuts off and oscillations cease. The reduction of the load on the power supply due to the oscillator switching off allows the output from rectifier 3 to rise to about 14 v. aiding the switching of transistors 23, 26. A further time constant circuit including capacitor 33 is provided to prevent transistor 26 from becoming conductive immediately should the oscillator fail to operate.
GB3255064A 1964-08-10 1964-08-10 Warning apparatus Expired GB1038304A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3255064A GB1038304A (en) 1964-08-10 1964-08-10 Warning apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3255064A GB1038304A (en) 1964-08-10 1964-08-10 Warning apparatus

Publications (1)

Publication Number Publication Date
GB1038304A true GB1038304A (en) 1966-08-10

Family

ID=10340342

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3255064A Expired GB1038304A (en) 1964-08-10 1964-08-10 Warning apparatus

Country Status (1)

Country Link
GB (1) GB1038304A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2177563A (en) * 1985-06-27 1987-01-21 Chu Kou Pao Electrical driving circuits

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2177563A (en) * 1985-06-27 1987-01-21 Chu Kou Pao Electrical driving circuits

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