GB1342468A - Security detection systems - Google Patents
Security detection systemsInfo
- 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
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
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.
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)
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 |
-
1969
- 1969-10-16 GB GB1342468D patent/GB1342468A/en not_active Expired
Cited By (7)
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 |