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Electronic article surveillance

Click here to learn more about RFID

New for July 2020: Eleacrnic article surveillance is the poor cousin of RFID. EAS does not identify the article, it merely tells a store owner that someone may be trying to move merchandise out of the stor without paying. According to Wikipedia, there are three broad categories of EAS:

  • Electro magnetic (useful for when the protected item is metallic)
  • Acousto-magnetic (trade name Emtag, you might have seen one on the cord of a power tool)
  • Radio frequency

Of course, here we are mostly interested in radio frequency stuff.

This technology dayes back to the 1950s, and there are many ways to implement it. In some cases the ID tag must be removed from the article during purchase (many clothing stores use this), in other cases the cashier passes the ID card over a strong EM filed and the teh tag is blown open (Lowes, Home Depot use this).

Reusable RF EAS

These parts must be robest enough to stop theives from pulling them off. Typically there is some type of magnetic latch to release the spike tha holds it togther.

Below, we took apart a re-usable tag, using a hammer.  

Disposable RF EAS

In this case, the budget for the part is near-zero.  SThe tabes are made in high-volume

 

Diodes Gone Wild explains EAS

 

Author : Unknown Editor

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