Most of the magnetic rings need to be painted to facilitate the distinction. Generally, the iron powder core is distinguished by two colors. The commonly used ones are red/transparent, yellow/red, green/red, green/blue and yellow/white. The manganese core ring is generally Painted green, iron-silicon-aluminum is generally all black and so on. In fact, the color of the magnetic ring after firing has nothing to do with the dyeing of the paint sprayed later, it is just an agreement in the industry. For example, green represents high permeability magnetic ring; two-color represents iron powder core magnetic ring; black represents iron silicon aluminum magnetic ring, etc., as shown in the figure

(1) High magnetic permeability ring

High permeability magnetic ring, we have to say nickel-zinc ferrite magnetic ring. The magnetic ring is divided into nickel-zinc and manganese-zinc according to the material. The magnetic permeability of the nickel-zinc ferrite magnetic ring material is currently used ranging from 15-2000. The commonly used material is nickel-zinc ferrite with a magnetic permeability of 100- 1000, press

Magnetic permeability classification, divided into low magnetic permeability materials. The magnetic permeability of manganese-zinc ferrite magnetic ring material is generally above 1000, so the magnetic ring produced by manganese-zinc material is called high permeability magnetic ring.

Nickel-zinc ferrite magnetic rings are generally used for various wires, circuit boards, and anti-interference in computer equipment. Manganese-zinc ferrite magnetic rings can be used to make inductors, transformers, filter cores, magnetic heads and antenna rods.

Generally, the lower the material permeability, the wider the applicable frequency range; the higher the material permeability, the narrower the applicable frequency range.

(2) Iron powder core ring

Iron powder core is a popular term for magnetic material ferric oxide, which is mainly used in electrical circuits to solve electromagnetic compatibility (EMC) problems. In practical application, various other substances will be added according to different filtering requirements in different frequency bands.

Early magnetic powder cores were "bonded" metal soft magnetic cores made of iron-silicon-aluminum alloy magnetic powders. This iron-silicon-aluminum magnetic powder core is often referred to as "iron powder core". Its typical preparation process is: use Fe-Si-Al alloy magnetic powder to be flattened by ball milling and used

The chemical method is used to coat the insulating layer, and then add about 15wt% of the binder, mix evenly, and then mold and solidify, and finally heat treatment (stress relief) to make the product. This traditional "iron powder core" product mainly works at 20kHz∼200kHz.

Because they have much higher saturation magnetic flux density than ferrites working in the same frequency band, good DC superposition characteristics, close to zero magnetostriction coefficient, no noise during operation, good frequency stability, and high performance-price ratio.

It has been widely used in electronic components such as high-frequency electronic transformers.

Their disadvantage is that the non-magnetic filling not only produces magnetic dilution, but also makes the magnetic flux path discontinuous, and local demagnetization leads to a decrease in magnetic permeability.

The recently developed high-performance iron powder core is different from the traditional iron-silicon-aluminum magnetic powder core. The raw material used is not alloy magnetic powder but pure iron powder coated with an insulating layer. The amount of binder is very small, so the magnetic flux density is large. increase in magnitude.

They work in the mid-low frequency band below 5kHz, generally a few hundred Hz, which is much lower than the working frequency of FeSiAl magnetic powder cores. The target market is to replace silicon steel sheets for motors with its low losses, high efficiency and ease of 3D design.

(3) FeSiAl magnetic ring

The iron-silicon-aluminum magnetic ring is one of the magnetic rings with high usage rate. In simple terms, iron-silicon-aluminum is composed of aluminum-silicon-iron and has a relatively high Bmax (Bmax is the average maximum magnetic flux on the cross-sectional area of ​​the magnetic core. flux density.), its core loss is much lower than iron powder core and

High magnetic flux, low magnetostriction (low noise), low cost energy storage material, no thermal aging, can be used to replace iron powder core, very stable performance at high temperature.

The main feature of FeSiAl is lower loss than iron powder core and good DC bias current characteristics. The price is not the highest, but not the lowest, compared with iron powder core and iron nickel molybdenum.

The iron-silicon-aluminum magnetic powder core has excellent magnetic and magnetic properties, low power loss and high magnetic flux density. When used in the temperature range of -55C~+125C, it has high reliability such as temperature resistance, humidity resistance and vibration resistance;

At the same time, a wide permeability range of 60~160 is available. It is the best choice for switching power supply output choke coils, PFC inductors and resonant inductors, with high cost performance.