eli5 how does nfc not need electricity?

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I can’t wrap my brain around how nfc just “holds data” but doesn’t need power to transmit data? Like how do ID cards use nfc?

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12 Answers

Anonymous 0 Comments

It’s an induced field situation. So it works in a similar way a metal detector works (imagine an old creepy fellow waving his metal detector over the beach). In that case, the metal detector has a battery and it sends a magnetic field into the sand. If it hits a hunk of metal, the metal will bounce back a signal, even though it doesn’t have its own battery.

The difference with a nfc chip, like in a credit card, is that the signal it bounces back is very specific because of the shape and pattern on the chip. And a nfc reader is sensitive enough to uncode that signal to get all the information it needs.

Anonymous 0 Comments

It’s an induced field situation. So it works in a similar way a metal detector works (imagine an old creepy fellow waving his metal detector over the beach). In that case, the metal detector has a battery and it sends a magnetic field into the sand. If it hits a hunk of metal, the metal will bounce back a signal, even though it doesn’t have its own battery.

The difference with a nfc chip, like in a credit card, is that the signal it bounces back is very specific because of the shape and pattern on the chip. And a nfc reader is sensitive enough to uncode that signal to get all the information it needs.