US Patent 9409490 Device alignment in inductive power transfer systems

This disclosure provides systems, methods and apparatus for wireless power transfer and particularly wireless power transfer to remote systems such as electric vehicles. In one aspect, a wireless power receiver includes a first inductive element configured to receive wireless charging power from a transmitter. The wireless power receiver further includes a second inductive element, laterally separated from the first, configured to receive wireless charging power from the transmitter. The wireless power receiver further includes a position detector configured to determine a lateral position of the receiver relative to the transmitter based on characteristics of the first and second inductive elements.