Winding Circular Coils on Square Equipment

Introduction to Winding circular coils with square equipment

The circular coil wound in square equipment is a coil structure formed by winding wires in a circular trajectory within the space limitations of a square shell, frame or PCB board. It takes into account the performance advantages of circular coils and the spatial characteristics of square devices, and is a common adaptive design.

I. Basic Structure and Winding Key Points

Wires and supports: Enameled copper wires are mostly used, with an insulating coating on the surface to prevent short circuits. Silver wires can be selected for high-frequency scenarios. The support foundation is usually a circular groove within a square device, an insulating skeleton or a circular wiring area on a PCB board. Some of them will fix the coil with limit mechanisms (such as grooves or baffles) to prevent the wire from sliding during winding.

Winding method: Parameters can be set through the automatic winding machine to control the tension and winding speed to complete the winding and ensure the regular shape of the coil. If there is a winding groove at the bottom of the equipment, the circular coil can be embedded in the groove in a vortex shape and fixed without the need for an additional frame. The diameter of the circular coil should be determined based on the internal space of the square equipment to avoid conflicts with the corner components.

Ii. Core Features

Superior performance: The magnetic field distribution of circular coils is more uniform and symmetrical, with stable magnetic field strength in the central region. The coupling coefficient is usually higher than that of square coils, which can improve energy transmission efficiency or induction accuracy. Its quality factor (Q value) is relatively high, resulting in less loss and stronger stability in high-frequency circuits.

Flexible space adaptation: Although it is wound in a circular shape, the diameter can be adjusted to fit the internal space of square equipment. For example, a circular bottom ring coil can be embedded at the bottom of the square coil coil, which not only takes advantage of the overall square structure of the equipment but also brings out the performance advantages of the circular coil.

Iii. Main Uses

Wireless charging and sensing: In square wireless chargers and NFC devices, circular coils can provide more uniform magnetic field coverage, improving charging efficiency or signal reading distance, and are compatible with square terminals such as mobile phones and smart cards.

Electromagnetic heating equipment: The coil plate of a square electric hot pot often adopts a combination of "square side ring + circular bottom ring". The circular bottom ring coil is wound in the bottom winding groove, enhancing the uniformity of heating.

In small electronic devices such as square sensors and precision controllers, circular coils can be used as inductive elements or sensing components. By leveraging their stable inductive characteristics and magnetic field performance, the performance of the equipment can be enhanced.

Four. Compatibility differences with square coils

Balance between performance and space: Circular coils have a more uniform magnetic field and a higher Q value, but there will be a small amount of corner space waste in square equipment. Although square coils have a high space utilization rate, their magnetic field distribution and coupling performance are slightly inferior.

Processing convenience: The winding of circular coils does not require complex corner fitting. The process is relatively mature and can be completed through standardized equipment. If square coils are extruded from circular coils, additional processes are required and it is easy to cause damage to the wires.