GB1342468A - Security detection systems - Google Patents

Security detection systems

Info

Publication number
GB1342468A
GB1342468A GB1342468DA GB1342468A GB 1342468 A GB1342468 A GB 1342468A GB 1342468D A GB1342468D A GB 1342468DA GB 1342468 A GB1342468 A GB 1342468A
Authority
GB
United Kingdom
Prior art keywords
capacitor
foam
capacitors
electrode
detected
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
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.)
Chubb Alarms Manufacturing Ltd
Original Assignee
Chubb Alarms Manufacturing 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 Chubb Alarms Manufacturing Ltd filed Critical Chubb Alarms Manufacturing Ltd
Publication of GB1342468A publication Critical patent/GB1342468A/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
    • G08B13/10—Mechanical actuation by pressure on floors, floor coverings, stair treads, counters, or tills

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

1342468 Capacitative alarm transducer CHUBB ALARMS MFG Ltd 18 Jan 1971 [16 Oct 1969] 50957/69 Heading G4N The presence or absence of a body is detected by a pressure sensitive capacitor. The capacitor may comprise two aluminium foil electrodes separated by polyurethane foam 14. In a preferred embodiment, the foam is folded round one electrode 12 and a second electrode 10 is wrapped round the foam. To avoid risk of short circuiting, the foil may be coated with a plastic film such as "Melinex" (Registered Trade Mark) or polythene. In operation a number of pressure senstive capacitors may be connected together in parallel and/or series and a small current is applied to charge the capacitors. If the capacitor separation is changed a voltage surge is produced. This is detected by a circuit comprising an input amplifier, a detector, and an output driver. The detector consists of two complementary connected transistors VT4, VT5, such that an output is produced if the voltage falls or rises. The two outputs are fed to an OR gate comprising transistors VT7, VT6, and then to an inverter stage VT8.
GB1342468D 1969-10-16 1969-10-16 Security detection systems Expired GB1342468A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5095769 1969-10-16

Publications (1)

Publication Number Publication Date
GB1342468A true GB1342468A (en) 1974-01-03

Family

ID=10458092

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1342468D Expired GB1342468A (en) 1969-10-16 1969-10-16 Security detection systems

Country Status (1)

Country Link
GB (1) GB1342468A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3009216A1 (en) * 1979-03-13 1980-09-25 Instrumentarium Oy DEVICE FOR DISPLAYING AND / OR RECORDING THE MOVEMENT OF A PERSON FOR MEDICAL EXAMINATION PURPOSES
GB2163885A (en) * 1984-08-07 1986-03-05 David Marshall Alarm device
GB2235090A (en) * 1989-08-17 1991-02-20 Vaisala Oy "Contacts for semiconductor transducers"
ES2255853A1 (en) * 2004-12-20 2006-07-01 Asociacion De Investigacion De La Industria Textil Presence detector for carpet has electronic system that converts variation in distance between conductive layers of condenser structure into signal that indicates presence of object or person on carpet
EP2050426A1 (en) * 2007-10-19 2009-04-22 INSERM (Institut National de la Santé et de la Recherche Médicale) Active floor mate to monitor sick person

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3009216A1 (en) * 1979-03-13 1980-09-25 Instrumentarium Oy DEVICE FOR DISPLAYING AND / OR RECORDING THE MOVEMENT OF A PERSON FOR MEDICAL EXAMINATION PURPOSES
GB2163885A (en) * 1984-08-07 1986-03-05 David Marshall Alarm device
GB2235090A (en) * 1989-08-17 1991-02-20 Vaisala Oy "Contacts for semiconductor transducers"
GB2235090B (en) * 1989-08-17 1993-11-17 Vaisala Oy Multilayer semi-conductor elements and their manufacture
ES2255853A1 (en) * 2004-12-20 2006-07-01 Asociacion De Investigacion De La Industria Textil Presence detector for carpet has electronic system that converts variation in distance between conductive layers of condenser structure into signal that indicates presence of object or person on carpet
EP2050426A1 (en) * 2007-10-19 2009-04-22 INSERM (Institut National de la Santé et de la Recherche Médicale) Active floor mate to monitor sick person
WO2009050285A1 (en) * 2007-10-19 2009-04-23 Inserm (Institut National De La Sante Et De La Recherche Medicale) Active floor mat to monitor sick person

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Legal Events

Date Code Title Description
PS Patent sealed
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee