Patent ID: 9293251
Filing Date: 2016-03-22
CPC Classification: H01F,H02J,H04B

Claim Text:
1. A method for exciting a primary coil in a contactless power supplying device that includes a plurality of primary coils and a plurality of power supplying unit circuits respectively exciting the plurality of primary coils, wherein the contactless power supplying device uses an electromagnetic induction effect to supply power to a power reception device opposed to at least one of the primary coils, the method comprising: dividing the plurality of primary coils into a plurality of groups of primary coils; providing synchronization signals to power supplying circuits in each group among a plurality of groups of power supplying unit circuits respectively corresponding to the plurality of groups of primary coils; calculating a frequency of each of the plurality of synchronization signals; comparing the calculated frequencies of the plurality of synchronization signals and a frequency of a reference clock signal; and when the calculated frequencies of the plurality of synchronization signals differ from the frequency of the reference clock signal, adjusting the differing frequencies of the plurality of synchronization signals to the frequency of the reference clock signal.