GB1087310A - Improvements in or relating to automatic alarm systems - Google Patents

Improvements in or relating to automatic alarm systems

Info

Publication number
GB1087310A
GB1087310A GB4060765A GB4060765A GB1087310A GB 1087310 A GB1087310 A GB 1087310A GB 4060765 A GB4060765 A GB 4060765A GB 4060765 A GB4060765 A GB 4060765A GB 1087310 A GB1087310 A GB 1087310A
Authority
GB
United Kingdom
Prior art keywords
bridge
circuit
alarm
normally
choke
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
GB4060765A
Inventor
Eric Fielding
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.)
Colt Ventilation and Heating Ltd
Original Assignee
Colt Ventilation and Heating 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 Colt Ventilation and Heating Ltd filed Critical Colt Ventilation and Heating Ltd
Priority to GB4060765A priority Critical patent/GB1087310A/en
Publication of GB1087310A publication Critical patent/GB1087310A/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • G08B29/02—Monitoring continuously signalling or alarm systems
    • G08B29/06—Monitoring of the line circuits, e.g. signalling of line faults
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/06—Electric actuation of the alarm, e.g. using a thermally-operated switch
    • 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
    • G08B29/02—Monitoring continuously signalling or alarm systems
    • G08B29/04—Monitoring of the detection circuits
    • G08B29/043—Monitoring of the detection circuits of fire detection circuits

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Emergency Alarm Devices (AREA)

Abstract

1,087,310. Automatic alarm systems. COLT VENTILATION & HEATING Ltd. Sept. 23, 1966 [Sept. 23, 1965], No. 40607/65. Heading G4N. A closed circuit automatic alarm system includes a bridge network a, b, c, d, having one arm a, b, consisting of a fusible link 10 and a choke 11 and an adjacent arm 6, c including a normally operated alarm circuit relay RLA having two sets of changeover contacts A1, A2. The impedance of bridge arms a, b and b, c is matched so that no alternating voltage is normally developed across an A.C. fault detector 25 connected across the bridge at b, d. A ripple voltage is applied to the bridge across junctions a, c by an A.C. mains power supply through transformer T1 and a full-wave bridge rectifier BR1. This bridge Supplies a rectified component which charges a battery 20 for the alarm circuit. A secondary alarm device, e.g. a lamp 16, is connected in parallel with the alarm circuit and is normally not lit by current flowing in bridge a, b, c, d but is lit by battery 20 when link 10 is fused. If a short circuit causes shorting out of fusible link 10 and choke 11 the bridge will be unbalanced and an A.C. voltage will cause current to flow through the circuit of fault detector 25 which comprises transistors (TR1), (TR2), Fig. 2 (not shown) isolated from D.C. flow across the output of the bridge circuit. A plurality of bridge networks a, b, c, d may be connected to the alarm circuit.
GB4060765A 1965-09-23 1965-09-23 Improvements in or relating to automatic alarm systems Expired GB1087310A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4060765A GB1087310A (en) 1965-09-23 1965-09-23 Improvements in or relating to automatic alarm systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4060765A GB1087310A (en) 1965-09-23 1965-09-23 Improvements in or relating to automatic alarm systems

Publications (1)

Publication Number Publication Date
GB1087310A true GB1087310A (en) 1967-10-18

Family

ID=10415728

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4060765A Expired GB1087310A (en) 1965-09-23 1965-09-23 Improvements in or relating to automatic alarm systems

Country Status (1)

Country Link
GB (1) GB1087310A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2432189A1 (en) * 1978-07-24 1980-02-22 Faget Jean Electronic surveillance alarm system with automatic checking - employs detectors in bridge network receiving periodic control pulses from generator
FR2513784A2 (en) * 1978-07-24 1983-04-01 Faget Jean Electronic alarm circuit using wheatstone bridge - has timing circuit suppressing short lived alarm signals and responding only to longer duration alarm before activating relay

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2432189A1 (en) * 1978-07-24 1980-02-22 Faget Jean Electronic surveillance alarm system with automatic checking - employs detectors in bridge network receiving periodic control pulses from generator
FR2513784A2 (en) * 1978-07-24 1983-04-01 Faget Jean Electronic alarm circuit using wheatstone bridge - has timing circuit suppressing short lived alarm signals and responding only to longer duration alarm before activating relay

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