RFID cards don’t have any power source inside them, but they have a small silicon chip and a fairly large aerial. When the card is brought near to the reader, the reader is transmitting a radio signal, and this induces a small current into the aerial in the tag or card. There is just enough power induced in this aerial to power up the chip inside the tag or card.
At time of manufacture, each tag or card is programmed with a unique number that identifies it. Every card in the world has a different number. Now, the reader transmits a known waveform through it’s aerial, and this is picked up by the card. The ID number programmed into it’s chip is used to interfere with the signal transmitted by the reader device, and the reader device can then detect these disturbances in the signal and decode the ID number as a result. All of this happens in just a few milliseconds.
RFID cards don’t have any power source inside them, but they have a small silicon chip and a fairly large aerial. When the card is brought near to the reader, the reader is transmitting a radio signal, and this induces a small current into the aerial in the tag or card. There is just enough power induced in this aerial to power up the chip inside the tag or card.
At time of manufacture, each tag or card is programmed with a unique number that identifies it. Every card in the world has a different number. Now, the reader transmits a known waveform through it’s aerial, and this is picked up by the card. The ID number programmed into it’s chip is used to interfere with the signal transmitted by the reader device, and the reader device can then detect these disturbances in the signal and decode the ID number as a result. All of this happens in just a few milliseconds.
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