INDRETNING TIL ALARMSYSTEMER, NAVNLIG SAAKALDTE BUTIKSALARMSYSTEMER

© In self-service stores, pay desks (1, 2, 3) are usually arranged in a row side by side. Anti-theft detectors are often arranged these days in conjunction with the pay desks, and comprise coil loops (7, 8, 9, 10, 11, 12) generating magnetic fields. The coils are usually fed with a common alternatin...

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Bibliographic Details
Main Author LUNDBERG LEIF BERTIL
Format Patent
LanguageDanish
Published 09.09.1986
Edition4
Subjects
ALARM SYSTEMS
ORDER TELEGRAPHS
PHYSICS
SIGNALLING
SIGNALLING OR CALLING SYSTEMS
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Summary:© In self-service stores, pay desks (1, 2, 3) are usually arranged in a row side by side. Anti-theft detectors are often arranged these days in conjunction with the pay desks, and comprise coil loops (7, 8, 9, 10, 11, 12) generating magnetic fields. The coils are usually fed with a common alternating current. The result of this is that an alarm-generating object at one pay desk (1) can give an alarm at the detectors of an adjacent pay desk (2). The invention is based on feeding the coil loops in alternate systems (7, 8 and 11, 12) with one alternating frequency and the ones in between (9, 10) with a deviating frequency, whereby detection isolation between the system (7, 8 and 11, 12) with the same frequency is achieved.
Bibliography:Application Number: DK19860001022