Eli5: how do anti theft radio frequency tags know i bought an item

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for context i just bought 3 bags of beef jerky from 5 below and they all had one of those square tags with the lines on them and i only scanned one 3 times at the self checkout how do they get deactivated

Edit [https://imgur.com/a/c3DFJFg](https://imgur.com/a/c3DFJFg) here’s a picture of it

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17 Answers

Anonymous 0 Comments

The stickers are an antenna with a very simple chip in the center that responds something akin to “I’m here!” when they get close to the panels at the door. Those panels are constantly sending out signals akin to “Anyone out there?” with enough power to power up the chip in the stickers. If the panels get a response then they sound an alarm.

The register or the bagging area has a similar device as the device door panels looking for an “I’m here!” message. But instead of sounding an alarm like the doors do, it kicks off a magnetic pulse generator that fries a simple fuse in any stickers near by (it can also demagnetize your credit cards). Once that fuse is blown, the sticker stops responding to the “Anyone out there?” signals.

The larger removable spider wraps, bottle tops, plastic boxes and punch tags do not have the fuse, so they aren’t deactivated by the magnetic pulse generator.

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