| 摘要 |
The present invention relates to a device with its related electronic circuit and to a detection process, targeted to detect any magnetic material moving around the antennas/sensors (6) used in Electronic Article Surveillance (EAS) electromagnetic systems, which can by internally or externally coupled to these kind of anti-theft systems, significantly decreasing its current vulnerability to fraud, since the current Electronic Article Surveillance (EAS) electromagnetic systems are vulnerable for not being able to detect magnetic materials. The present process and detector device suppress that vulnerability by correctly filtering and processing the DC signal generated by the displacement of a magnetic material around one or more EAS electromagnetic system antenna/sensor(s) (6). Magnetic material detection is achieved from a differential signal existing in the antenna/sensor (6) receiver element of said EAS electromagnetic system, which is forwarded to the control unit (7) of said system, where there are coupled a device comprising a "n" order filter (1), a buffer or insulator circuit (2), a sensitivity adjuster or gain control circuit (3), a control logic (4) and an alarm module (5).
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