As shown in the figure above, the sending module consists of AC/DC power conversion, driver, transmitting coil, voltage and current detection and controller. The alternating current of a certain frequency is given to the primary coil, and a certain current is generated in the secondary coil through electromagnetic induction, thereby transferring energy from the transmitting end to the receiving end. At present, this method of transferring electric energy has been widely used in the low-power, short-distance wireless charging market, such as electric toothbrushes, mobile phones, cameras and other small portable electronic devices, which are generally wirelessly charged by the charging base.