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

Claim 0:
1. An apparatus for detecting a presence of an object in an inductive charging system, the apparatus comprising:
a first electrically conductive structure configured to wirelessly transmit 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 a respective second electrically conductive structure different from the first electrically conductive structure 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 second electrically conductive structures forming a portion of a multi-dimensional array of electrically conductive structures positioned within the alternating magnetic field generated by the first electrically conductive structure; and
a detection circuit configured to generate a sense current in the respective second electrically conductive structure of at least one of the plurality of resonant sense circuits and configured to measure an impedance characteristic of the at least one of the plurality of resonant sense circuits and detect the presence of the object based on the measured impedance characteristic,
wherein the detection circuit is configured to selectively apply the sense current to any one of the plurality of resonant sense circuits.