Method and apparatus for wireless power transfer utilizing transmit coils driven by phase-shifted currents

摘要

An apparatus comprises a first driver circuit having a first output impedance while driving a plurality of couplers with a first current having a first phase to generate a wireless field. A second driver circuit drives the plurality of couplers with a second current having a second phase. A controller causes the second driver circuit to sequentially drive each of the plurality of couplers with the second current while causing the first driver circuit to simultaneously drive the other couplers with the first current. The controller identifies a subset of the plurality of couplers based on detecting a change from the first output impedance in response to each of the plurality of couplers being sequentially driven with the second current. The controller selectively energizes the subset of the plurality of couplers via one or both of the first and second driver circuits to wirelessly transfer the charging power.