GB1429781A - Multi-point alarm systems - Google Patents

Multi-point alarm systems

Info

Publication number
GB1429781A
GB1429781A GB955872A GB955872A GB1429781A GB 1429781 A GB1429781 A GB 1429781A GB 955872 A GB955872 A GB 955872A GB 955872 A GB955872 A GB 955872A GB 1429781 A GB1429781 A GB 1429781A
Authority
GB
United Kingdom
Prior art keywords
alarm
resistor
detector
unit
bridge
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
GB955872A
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.)
CHILD J V
Original Assignee
CHILD J V
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 CHILD J V filed Critical CHILD J V
Priority to GB955872A priority Critical patent/GB1429781A/en
Publication of GB1429781A publication Critical patent/GB1429781A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/02—Mechanical actuation
    • G08B13/08—Mechanical actuation by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Alarm Devices (AREA)

Abstract

1429781 Alarm systems J V CHILD 1 March 1973 [1 March 1972] 9558/72 Headings G4N and G4H [Also in Division G1] An alarm system for burglar, fire or industrial alarm applications comprises a resistance bridge 10 having in one arm a series connection of a plurality of detector units 21-24, each comprising a first fixed resistor 25 of at value common to all the detector units and a second series resistor 26 of a value characteristic of that unit and each detector unit being arranged to have an effective resistance either in the set or released state whose value is different and characteristic of that unit and also having in a second arm a calibrated variable resistor 18, 19, an input supply source, e.g. a transistorized L.F. oscillator 12, a null detector 15 or 29 arranged to detect imbalance of the bridge and activate an alarm device 28. The detector units may include reed, micro or other mechanically operated switches or comprise a pair of contacts to be bridged by rising water or other liquid. In use, with calibrated resistor 19 in an initial position, presetting resistor 18 and capacitor 20 are adjusted to obtain a null bridge balance condition indicated by a loud-speaker 29. When an alarm condition occurs; the corresponding detector contacts 27 are actuated to produce a bridge imbalance detected by an alarm relay unit 15 for operating an alarm device 28. To prevent false operation arising from transient conditions, the alarm is arranged to be-operable only after a predetermined delay. With an alarm condition, the calibrated variable resistor 19 is adjusted to reobtain bridge balance and the change in resistance value is indicative of the origin or location of the alarm condition. The detector contacts may be arranged to short out the resistor 26 in the initial state or in the detecting state. The unit 15 may include a time delay to prevent false alarms. The power supply 12 may include a time delay to enable an authorized person to set the alarm circuit and vacate the premises.
GB955872A 1972-03-01 1972-03-01 Multi-point alarm systems Expired GB1429781A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB955872A GB1429781A (en) 1972-03-01 1972-03-01 Multi-point alarm systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB955872A GB1429781A (en) 1972-03-01 1972-03-01 Multi-point alarm systems

Publications (1)

Publication Number Publication Date
GB1429781A true GB1429781A (en) 1976-03-24

Family

ID=9874315

Family Applications (1)

Application Number Title Priority Date Filing Date
GB955872A Expired GB1429781A (en) 1972-03-01 1972-03-01 Multi-point alarm systems

Country Status (1)

Country Link
GB (1) GB1429781A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0015656A2 (en) * 1979-02-09 1980-09-17 Philip Charles Sefton Improvements relating to security equipment
US4401980A (en) * 1977-10-07 1983-08-30 The United States Of America As Represented By The Secretary Of The Army Constant current electronic intruder detection system
US4491828A (en) * 1978-10-16 1985-01-01 American District Telegraph Company Two-wire multi-zone alarm system
EP0130702A1 (en) * 1983-06-02 1985-01-09 Kennett Charles Warner Alarm system
FR2550642A1 (en) * 1983-08-08 1985-02-15 Pittway Corp SERIAL SWITCH MONITORING SYSTEM
GB2154037A (en) * 1984-02-01 1985-08-29 Thorn Emi Ferguson Alarm unit
GB2297410A (en) * 1995-01-27 1996-07-31 Cetsa Ltd An electrical circuit for use in a security system
GB2401998A (en) * 2003-05-17 2004-11-24 Kac Alarm Company Ltd Alarm system call point
DE102010056006A1 (en) 2010-12-23 2012-06-28 Volkswagen Ag Method for monitoring traction network for e.g. hybrid vehicle, involves monitoring change of total resistance, and performing action relative to line network when total resistance change is detected larger than preset value

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4401980A (en) * 1977-10-07 1983-08-30 The United States Of America As Represented By The Secretary Of The Army Constant current electronic intruder detection system
US4491828A (en) * 1978-10-16 1985-01-01 American District Telegraph Company Two-wire multi-zone alarm system
EP0015656A2 (en) * 1979-02-09 1980-09-17 Philip Charles Sefton Improvements relating to security equipment
EP0015656A3 (en) * 1979-02-09 1981-01-07 Philip Charles Sefton Improvements relating to security equipment
EP0130702A1 (en) * 1983-06-02 1985-01-09 Kennett Charles Warner Alarm system
GB2145863A (en) * 1983-08-08 1985-04-03 Pittway Corp Monitoring system
FR2550642A1 (en) * 1983-08-08 1985-02-15 Pittway Corp SERIAL SWITCH MONITORING SYSTEM
GB2154037A (en) * 1984-02-01 1985-08-29 Thorn Emi Ferguson Alarm unit
GB2297410A (en) * 1995-01-27 1996-07-31 Cetsa Ltd An electrical circuit for use in a security system
GB2297410B (en) * 1995-01-27 1998-09-30 Cetsa Ltd An electrical circuit comprising a plurality of bi-state devices arranged for determining a device by type which has changed state
GB2401998A (en) * 2003-05-17 2004-11-24 Kac Alarm Company Ltd Alarm system call point
GB2401998B (en) * 2003-05-17 2006-07-19 Kac Alarm Company Ltd Call point for alarm system
DE102010056006A1 (en) 2010-12-23 2012-06-28 Volkswagen Ag Method for monitoring traction network for e.g. hybrid vehicle, involves monitoring change of total resistance, and performing action relative to line network when total resistance change is detected larger than preset value
DE102010056006B4 (en) 2010-12-23 2019-05-09 Volkswagen Ag Method for monitoring a pipeline network for a vehicle and corresponding monitoring device and vehicle

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee