Patent ID: 7262700
Filing Date: 2007-08-28
Classification: H02J

Abstract:
1. A system for powering portable devices, comprising: a powering device having an inductive powering surface with a plurality of primary coils formed therein and a controller for selectively energizing the primary coils; and a portable device having a secondary coil, a power supply circuit coupled to the secondary coil, and a passive locator device, the passive locator device being configured to be powered up by receiving transmissions of a sensing frequency and to transmit a response at the sensing frequency, the controller of the powering device being programmed to scan the primary coils to locate the secondary coil by energizing each of the primary coil at the sensing frequency and sensing whether a response by the passive locator device is received by said each primary coil, and to energize a group of primary coils located under the secondary coil at a power transfer frequency to transfer power to the portable device via inductive coupling between the group of primary coils and the secondary coil, the sensing frequency being significantly higher than the power transfer frequency.