The principle of mobile phone wireless charging in the general sense is the process of converting electric energy into magnetic field, magnetic field through air, and magnetic field into electric energy.
The principle of wireless charging is similar to the transformer in the popular sense. The transformer magnetic field coupling loop is a magnetic conductor. The wireless charging magnetic field coupling loop is air, and the magnetic medium is different.
There are generally four major technologies for wireless charging in the industry: magnetic induction technology, magnetic resonance technology, microwave technology and electric field coupling technology.
Among the mainstream technologies are magnetic induction technology and magnetic resonance technology.
Magnetic induction wireless charging technology
When the transmitting coil passes an alternating electric signal, the alternating electric field will generate a changing magnetic field through the transmitting coil, and the changing magnetic field will effect the magnetic coupling of the coil around it. According to Faraday's law of electromagnetic induction, the changing magnetic field will generate electric field.
Therefore, the magnetic field generated by the transmitter coil will pass through the receiver coil, and the receiver coil will generate an electric field. If the receiver coil is terminated with a load, a current will be generated.
MRI wireless charging technology is a special case of magnetic induction technology. It is similar to the resonance of our sound. When the system's oscillation frequency is the same as the natural frequency of the system, resonance occurs. When resonance occurs, the system's energy intensity reaches its maximum. point.
Magnetic resonance wireless charging technology is that when the resonant frequency of the receiving coil coincides with the resonant frequency of the transmitting coil, magnetic resonance occurs, and energy is transmitted from the transmitting end to the receiving end.