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RFID Tag Detector

Eric Simon

Mar 22, 2016
2
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Mar 22, 2016
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Hi all, I am new to the forum and was wondering if someone could provide me with some assistance on a project I am working on.

I am trying to create a small device that will detect passive RFID chips at a distance of about 12 inches away. I have no need to read the data on the chip, I simply want to detect its presence and have a light flash indicating that a chip was found.

I purchased one of these to get me started. http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=141668399650&rmvSB=true

I was hoping that there would be a simple polarity change in one of the pins when the chip was brought close by, but no such luck.

Can anyone help guide me in the right direction?

Thanks,
Eric
 

AnalogKid

Jun 10, 2015
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Jun 10, 2015
Messages
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12 inches is an enormous distance for an RFID tag. While shoplifting tags can be detected at this distance, they work on a different principle.

Separate from that, I think you need to read up on how passive RFID works. It is a broadcast-powered electric field modifier, and since anything metallic can modify an electric field, detection relies on being able to interact with the tag and read its response.

ak
 

Eric Simon

Mar 22, 2016
2
Joined
Mar 22, 2016
Messages
2
Ya, that is what I was getting from my research. I was hoping that this would be something more simpler as detecting instead of reading. I am really trying to figure out a way to place passive tags on objects and be able to have a detector pick them up at about 12 inches. RFID seemed like the way to go at the onset.

Thanks for the quick response.
 

Colin Mitchell

Aug 31, 2014
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Aug 31, 2014
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The distance depends on the power of the transmitter.

Elektor had an article on this.
 
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