The wireless charging receiving coil to charge the device refers to the device that uses the principle of electromagnetic wave induction to charge. The principle is similar to that of a transformer. There is a coil at the sending end and the receiving end. The electromagnetic signal generates current to charge the battery. The coil uses enameled wire or silk-covered wire. The thickness and the number of turns have to be calculated actually. The thickness must be able to bear the passing current, and the number of turns depends on the transformation coefficient and energy conversion. With the rapid development of wireless charging market, the prospect of wireless charging market is becoming more and more extensive, and it is more and more favored by the market!
Wireless charging receiver coilIt can transmit energy for energy transfer, and can also receive energy for energy transfer, while the wireless charging and transmitting coil can only transmit energy for energy transfer but cannot receive energy for energy transfer.
Wireless charging receiving coils are often multi-strand wire-covered wires, multi-strand thinner enameled wires or inductive coils wound with yarn-covered wires are mostly used in circuits with relatively high frequencies, such as magnetic antenna rod coils of radios, and short-wave radio mid-circle coils. The high-frequency transformer coils of the liquid crystal display lighting circuit, etc., often use multi-strand wires. You may know that the high-frequency current passes through the conductor, and as the distance from the conductor surface gradually increases, the current density in the conductor decreases exponentially. That is, the current in the conductor will concentrate on the surface of the conductor.
From the cross-section perpendicular to the current direction, the current intensity of the central part of the conductor of the wireless charging receiving coil is basically zero, that is, almost no current flows, and only the edge of the conductor will have current. Simply put, the current is concentrated in the conductor The skin part of the conductor, so it is called the skin effect. The main reason for this effect is that the changing electromagnetic field produces a vortex electric field inside the conductor, which cancels out the original current.
Obviously in high-frequency applications, if only one wire is used because its surface area is relatively small, the current utilization rate will be greatly reduced, causing serious wire heating or increased signal attenuation, which is obviously not what we want. One of the simplest methods of skin effect is to use multi-strand wires in parallel. The wireless charging receiving coil makes the magnetic field generated by the current more uniform. In layman's terms, it provides a larger area of "skin" path for the current. It can also be seen by comparison. , The same high-frequency transformer with similar power and volume, the wireless charging receiving coil is wound with a single-strand enameled silk, and the heat generation is much larger than that of the multi-strand wire.