> From: "Trei, Peter" <[EMAIL PROTECTED]> > Date: Wed, 28 Aug 2002 11:24:15 -0400
> I wonder about induction too - could you put a small magnet in > the disk, and use the varying induced fields in the reader > mechanism to generate power? Contactless smart cards typically have coils in the card and the magnetic field is generated by the reader. Capacitive coupling is an alternative but requires more precise alignment and thus doesn't really provide a proximity/vicinity card like inductive coupling does. On-board batteries are hard to fit on an ISO-format smart card but maybe with the new ultra-thin batteries that's no longer the case. Batteries are perhaps more suitable for a CD. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
