Coil-type Mosquito Coil

Introduction to Mosquito coil type coils

Mosquito-repellent coil is a type of wire wound in a "spiral involute" manner, presenting an overall coiled structure similar to mosquito coils. Its core feature is that within a limited planar space, the wire length is significantly increased through spiral arrangement, while achieving concentrated or uniform coverage of the magnetic field. It is commonly seen in scenarios with high requirements for spatial compactness.

I. Basic Structure

Wire: Mostly enameled copper wire (mainly thin diameter, suitable for helical winding), with an insulating coating on the surface to prevent short circuits in adjacent helical layers, ensuring conductivity and energy storage efficiency.

Support base: Mostly thin insulating materials (such as epoxy boards, plastic sheets), used to fix spiral wires and prevent coil deformation. The base is usually in the same disc shape as the coil and is thin (suitable for flat installation).

Lead wire: The extension section of the wire at both ends of the coil, used to connect the circuit. It needs to be insulated to ensure safe connection with other components.

Ii. Core Features

Extremely high space utilization: The helical tapering structure can wind a large number of wires in a small planar area (such as a few square centimeters to tens of square centimeters), significantly saving space compared to straight winding or ring-shaped coils, making it suitable for small electronic devices.

Concentrated magnetic field distribution: When current passes through, the magnetic field mainly concentrates in the central area of the spiral coil or forms a uniform planar magnetic field along the spiral trajectory, which is suitable for scenarios that require local strong magnetic fields or planar magnetic field coverage.

The inductance characteristics are stable: The length and number of turns of the helical structure wire are easy to precisely control, the inductance value stability is high, and it is less disturbed by the external space.

Iii. Main Uses

Small electronic devices: such as the charging coils of mobile phones and smartwatches (flat wireless charging), and the inductive components of Bluetooth headphones, take advantage of their compact structure to adapt to the narrow space inside the devices.

In the field of sensors: such as proximity sensors and planar magnetic field sensors, by leveraging their concentrated or uniform magnetic field characteristics, the detection sensitivity and accuracy can be enhanced.

High-frequency circuits: Such as resonant coils in RF circuits, the helical structure can reduce parasitic capacitance between wires, adapt to high-frequency working environments, and ensure circuit stability.

Iv. Simple Differences from Conventional Coils

Spatial form: The mosquito coil type has a planar spiral structure, which saves space. Circular and square coils are mostly wound in three dimensions, taking up more space.

Magnetic field range: The magnetic field of mosquito-repellent incense type is concentrated within the plane (central or spiral area). The magnetic fields of conventional coils are mostly distributed in three dimensions and are prone to diffusion.

Applicable scenarios: Mosquito-repellent incense type is suitable for small-sized and flat devices. Conventional coils are more suitable for scenarios with low space requirements and the need for three-dimensional magnetic fields (such as motors and large inductors).