Magnetic Materials in Wireless Charging Devices

Charging batteries built into electronic devices through Wireless, contactless Wireless Power Transfer is gaining popularity. There are a variety of wireless charging methods, but the prevailing methods are electromagnetic induction and magnetic resonance for power transmission through magnetic coupling.

Electromagnetic induction and magnetic resonance wireless charging is to transmit power in a non-contact way through the magnetic field generated by the receiving and transmitting coils.

Electromagnetic induction wireless charging

Most of the wireless phone chargers on the market today are electromagnetic induction. Electromagnetic induction wireless charging has been widely used in electric shavers, electric toothbrushes, mobile phones and other products, its advantages are simple principle and structure and low cost; However, when the relative position and distance between the transmitting coil and the receiving coil become larger, the efficiency of power transmission decreases rapidly, so the coils must be kept close to each other, which is also the disadvantage of this technology.

Magnetic resonance wireless charging

Magnetic resonance wireless charging is a way of power transmission by inserting capacitors on the transmitting side and receiving side to form LC resonant circuits, so that the resonant frequencies of the transmitting side and receiving side are consistent. The advantage of this method is that the distance between the coils can be extended and power can be transferred even if the center of the coils is slightly shifted. This charging method can be used for wireless charging of multiple mobile devices simultaneously.

Wireless charger is mainly used in the magnetic material NdFeb permanent magnet, nickel zinc ferrite thin magnetic sheet, manganese zinc ferrite thin magnetic sheet, flexible ferrite magnetic sheet. As the main components of wireless charging technology, various magnetic insulation sheets made of soft magnetic ferrite materials play a role in increasing the induced magnetic field and shielding coil interference in wireless charging equipment.

Fixed-position wireless chargers generally use Ndfeb permanent magnet pieces as positioning materials. Terminal devices need to be placed in a fixed position to charge and maximize charging efficiency. (Large wireless charging equipment will use permanent magnet ferrite material instead of NdFeb to reduce costs)

The permanent magnet material applied in wireless charging equipment, on the one hand, acts as a positioning device between transmitting and receiving, which facilitates the rapid and correct positioning of terminal equipment; on the other hand, it enhances the magnetic flux between transmitting and receiving coils, and improves transmission efficiency.