Patent ID: 9515515
Filing Date: 2016-12-06
CPC Classification: H02J,Y02B

Claim Text:
1. A contactless charging system which includes a transmitting unit having a primary coil and a receiving unit having a secondary coil, which charges a battery electrically connected to the secondary coil by electromagnetic induction generated between the primary coil and the secondary coil, and which supplements charging efficiency of the battery by varying a charging frequency between 110 kHz and 205 kHz used in the electromagnetic induction in proportion to the charging efficiency battery that varies according to the position of the secondary coil relative to the primary coil, the system comprising: a charging efficiency notifying device installed in the transmitting unit or the receiving unit, wherein the charging efficiency notifying device includes a frequency detecting unit detecting the charging frequency when charging is performed by making the receiving unit get close to the transmitting unit and a notification unit outputting the charging efficiency acquired from the detected charging frequency to enable a user to know the charging efficiency, and wherein the charging frequency used in the electromagnetic induction is calibrated by detecting the charging frequency at a plurality of positions of the receiving unit relative to the transmitting unit, acquiring a minimum value and a maximum value from the plurality of detected charging frequencies and adjusting an offset value herein.