An inductive powering device provides power to a portable device via
inductive coupling between primary coils in the surface of the powering
device and a secondary coil in the portable device. The portable device
includes a passive locator device, such as an RFID device, to allow the
primary coils of the inductive powering surface to detect the presence
and location of the secondary coil, and only primary coils adjacent the
secondary coil are energized for power transfer. A cost-effective driving
configuration that arranges the primary coils into a matrix with drive
circuits switchably connected to the row and columns is used to energize
the primary coils.