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by ansgri 4287 days ago
If variable speed would prevent the reader from working, how do the manual swipe readers work?
1 comments

Cards are usually swiped in a somewhat smooth motion. Even then, it's easy to fail the motion, and you often need to swipe again.

The anti-skimmer moves the card very fast in short bursts, so while it may seem just a bit jittery (averaged out), the skimmer will end skipping whole pieces of band or losing sync.

Maybe they could use small rubber rollers to detect velocity and sync appropriately, like in a mouse.