The function of magnetic separators made of absorbing materials in the field of wireless charging is summarized. It is convenient for friends in need to check and browse. Electromagnetic radiation causes direct and indirect harm to human body through thermal effect, non thermal effect and cumulative effect.
The results show that the ferrite absorbing material has excellent properties, such as high absorption band, high absorptivity and thin matching thickness. This kind of absorbing material can absorb the leakage electromagnetic radiation in electronic equipment, and can eliminate the electromagnetic interference. According to the law of electromagnetic wave propagating from the direction of low magnetism to high permeability in medium, high permeability ferrite is used to guide electromagnetic wave. Through resonance, a large amount of radiation energy of electromagnetic wave is absorbed, and then the energy of electromagnetic wave is transformed into heat energy through coupling.
Schematic diagram of wireless charging principle:
Schematic diagram of wireless charging principle
Wireless charging technology uses magnetic resonance to transmit charge in the air between the charger and the device, and the coil and capacitor form resonance between the charger and the device. The design uses magnetic resonance instead of more traditional electromagnetic induction. Currently, many wireless charging systems rely on the electromagnetic induction between coils. The working distance of this way is too short, and the equipment needs to be placed on the charging stand, which also consumes a lot of power. Part of the charging system is based on magnetic resonance, and the electricity can be transmitted wirelessly between the coils that resonate at the same frequency. The wireless charger is a device that uses the electromagnetic wave induction principle to charge. There is a coil between the transmitting end and the receiving end of the wireless charger. The coil at the transmitting end is connected with an alternating power supply to generate alternating electromagnetic field, and the coil at the receiving end senses the electricity at the transmitting end The magnetic field signal generates an electric current to charge the battery.
Wireless charging separator
The role of magnetic separator made of absorbing materials in wireless charging field:
1) One of them is that the transmitting device is connected with energy, it does not emit electromagnetic waves, but uses the oscillator to generate high-frequency oscillation current, which emits electromagnetic waves through the transmitting coil, forming a non radiating magnetic field around, that is, converting electric energy into magnetic field;
2) When the natural frequency of the receiving device is the same as the received electromagnetic wave frequency, the oscillation current generated in the receiving circuit is the strongest, completing the conversion from magnetic field to electric energy, so as to realize the efficient transmission of electric energy;
3) A typical wireless power transmission system using electromagnetic resonance is proposed. The higher the frequency of electromagnetic wave, the more energy it radiates to space, and the higher transmission efficiency.
4) Because the coil magnetic field will produce battery interference or eddy current effect on other electronic components of the device, resulting in battery heating and other waste of electric energy, so it is necessary to use high permeability wireless charging magnetic separator to guide the magnetic circuit;
5) The electromagnetic field will form a dense magnetic return path in the internal part of the wireless charger under the traction of the magnetic separator, so as to prevent the magnetic field deviation from interfering with other electronic components, isolate the metal environment from heating with the metal, and improve the charging efficiency. The test results show that the wireless transmission distance is about 15 cm, but Fujitsu said that the wireless transmission distance can be realized several meters. It should be pointed out that the farther away from the equipment, the more power is lost in transmission.
Absorbing material: www.goodsmaterial.com