Chip and pin cards

[David H]

Until these arrived I thought all circuits needed power, but the chip on these has no battery, so all I can think is it must have a normal unpowered memory which is activated by an induction loop when read. Is this the case or is there another system that makes it work?

[Skids]

The chip is solid state memory which is powered by the reader when the reader's contacts contact the different segments of the chip's face.

[tomd]

A floppy disk or CD doesn't have power, it's only data stored there.

[David H]

True, but from the look of them the chips look more like integrated circuits which do. I think skids gave the answer though.

[buildersmate]

Skids answer is correct, but some circuits don't need to be in actual physical contact to get power from the reader - they do it by transfer of RF power.