Patent ID: 11919407
Assignee: WITRICITY CORPORATION
Field: Measurement (Instruments)
Classification: CPC B  G  H  Y | IPC B  G  H

Claim 12:
13. An apparatus for detecting a presence of an object in an inductive charging system, the apparatus comprising:
means for wirelessly transmitting power via generating an alternating magnetic field to power or charge a load, the magnetic field operating at a frequency;
a plurality of resonant sense circuits each comprising an electrically conductive structure different from the means for wirelessly transmitting power and electrically connected in series to a respective capacitor each of the plurality of resonant sense circuits having a respective resonant frequency different than the frequency of the alternating magnetic field, each of the respective electrically conductive structures forming a portion of a multi-dimensional array of electrically conductive structures positioned within the alternating magnetic field generated by the means for wirelessly transmitting power;
means for generating a sense current in the respective second electrically conductive structure of at least one of the plurality of resonant sense circuits;
means for measuring an impedance characteristic of the at least one of the plurality of resonant sense circuits;
means for detecting the presence of the object based on the measured impedance characteristic; and
means for selectively applying the sense current to any one of the plurality of resonant sense circuits.