Permanent magnet in Apple magnetic suction wireless charger
Since the iPhone 8 in 2017, Apple has added the wireless charging function to all iPhone models, which is close to the use of other mobile phone wireless charging methods. It starts charging when it is placed on the wireless charger. This wireless charging depends on the alignment of the transmitting coil and the receiving coil, which can not achieve the best effect when it is placed casually. If it is placed askew, the wireless charging efficiency will be reduced Problems such as poor power, slow charging and serious heating hinder the development of wireless charging and bring a poor experience.
Starting from the root, Apple launched a new MagSafe magnetic suction charging technology to solve the bad experience of traditional wireless charging. The iPhone 12, peripheral accessories and charger are equipped with MagSafe magnetic components to achieve the effect of automatic positioning and alignment.
How does MagSafe magnet charging work
As can be seen from the perspective view of iPhone 12, the MagSafe magnetic suction charging system has a component structure, a unique winding coil to withstand greater receiving power, capture magnetic flux through the nanocrystalline panel, and adopt an improved shielding layer to accept wireless fast charging more safely. The wireless magnetic coil is integrated with other dense coils to improve the wireless magnetic coil receiving efficiency. Equipped with a high-sensitivity magnetometer, the iPhone 12 can quickly identify the magnetic suction accessories and prepare for wireless charging.
MagSafe magnetic suction charger is quite different from the traditional charger in use. The metal shell is flat and round, with a power supply cable, which is small and lightweight. When the iPhone 12 is placed, the MagSafe magnetic suction charger directly bounces up because of the strong magnetic force and gives a “click”, which automatically aligns with the magnetic ring on the mobile phone and firmly adsorbs it. The transmitting coil and receiving coil reach the millimeter level alignment accuracy that can not be reached by hand, so as to realize high-efficiency and high-power charging.
Compared with wired charging, the wireless charging system has the ease of release and charge, but the energy transmission process across the air depends on the accurate alignment of the transmitting coil and the receiving coil. Apple applied the magnetic attraction technology to the wireless charging, which solves the problem that it is difficult to align the wireless charging. There is no possibility of skewing, so as to optimize the wireless charging efficiency and improve the wireless charging power. It becomes feasible to double the wireless charging power of this generation of iPhone 12 from 7.5W to 15W, greatly improve the wireless charging speed and reduce the waiting time of users.
The convenient adsorption of MagSafe magnetic suction charging can develop more playability. For accessories, magnetic suction charging also supports Qi wireless charging standard, which means that third-party manufacturers can develop 7.5W Qi standard magnetic wireless charger and other accessories by themselves.
Qi transmits power based on the principle of electromagnetic induction. The basic principle of inductive coupling electric energy transmission system is shown in the right figure. The system consists of transmitter coil and receiver coil. The two coils together form an electromagnetic coupling inductor.
The alternating current carried by the transmitter coil generates a magnetic field and causes the receiver coil to generate voltage through induction. This voltage can be used to power mobile devices or charge batteries. This kind of fixed position wireless charger will use Nd-Fe-B permanent magnet for positioning, so that the terminal equipment can be placed in a fixed position to maximize the charging efficiency.
Source: China Permanent Magnet Manufacturer – www.rizinia.com