Wireless charging coils are widely used, and the shapes and winding methods of inductance coils are diverse. Different winding equipment will be used to wind different coils, due to the requirements of different charging equipment composition.

There are many styles and varieties of coil products produced, and the applicable wireless charging devices are also very wide. Different wireless charging coils are designed according to user needs.

Today we will intruduce how to comfirm the Wireless Charging Coil Model ?

1. According to circuit requirements , Select winding method

When winding a wireless charging coil, it is necessary to consider the requirements of the wireless charging device circuit, inductance, and wire size. Confirm the winding method before making the mould.

Wireless charging coils are basically wound from the inside out, so the first step is to confirm the inner diameter. Confirm the layers, height, outer diameter, etc. of the coil based on electrical factors such as inductance and resistance.

Wireless charging coils are suitable for short wave and medium wave circuits, with Q values from 150 to 250 , high stability.

After the wireless charging coil is electrified, it forms a magnetic field around it, forming a spiral shape. The more coils there are, the larger the magnetic field scale. The more electricity passes through per unit time, the stronger the magnetic field. Based on the skin effect of the current, thick wires can obtain a stronger magnetic field than thin wires.

To improve space utilization, the wire used for the coil is generally insulated enameled wire. When choosing automation equipment for winding, wire arrangement is very important, For a single wire, what needs to be considered is the turns and layers.

The placement method of the coil is determined based on whether it needs to save space or improve heat dissipation, and there is often an irreconcilable relationship between several requirements.

When winding the wireless charging coil, we should pay attention to the above mentioned things.


2. According to working frequency, select suitable core.

Coils with different frequency have different characteristics, and magnetic cores of different materials should be selected based on the characteristics.

Wireless charging receiving coil used in audio low frequency operation, generally using silicon steel sheet or permalloy as the magnetic core material. Low frequency ferrite is used as the magnetic core material, which has a large inductance, and the inductance of wireless charging coil can be as high as a few to several tens of Henry.

For coils in the medium wave broadcasting section, ferrite cores are generally selected and wound with multiple insulated wires. For high frequency, the coil will uses high-frequency ferrite as the magnetic core, and hollow coils are also commonly used. In this situation, it is not advisable to use multiple insulated wires, but rather to use single strand thick silver plated wire for winding.

If frequencies above 100MHz, ferrite cores are generally no longer available, and wireless charging and receiving coils can only use hollow coils; If you want to make minor adjustments, you can use a steel core.

In addition to meeting the requirements of the circuit for inductance and rated current, it is also important to note that the distributed capacitance of the wireless charging coil used in high-frequency circuits should not be too large.


Post time: Jun-19-2023