Magnetic cores are commonly-used components in electronic circuits. What are the differences between different materials, different sizes, different appearances, and even different colors? What is the basis for distinguishing? Today we will briefly talk about several commonly-used toroidal magnetic cores.

    Ferrite core

    Ferrite cores are often divided into nickel-zinc ferrite cores and manganese-zinc ferrite cores. Nickel-zinc ferrite core has low permeability and is generally gray-black. It has good impedance characteristics in high frequency band, so it is generally used for filtering in high frequency band at the circuit board end, playing an anti-interference role, so it is also called high frequency ferrite core. The permeability of manganese-zinc ferrite core is much higher than that of the former. It is generally painted green and used in the middle and low frequency band. In addition, because of its high permeability, the manganese-zinc ferrite core is widely used to make common mode inductor, which can be used to solve low-frequency common mode conduction interference at the power interface.

    Ferrite core is one of the main products of Strictron Electronics, for more information, please refer to this page: https://www.strictron.com/ferrite-core-and-bead

    Sendust core

    As its name suggests. This kind of core is composed of iron-silicon-aluminum mixed materials. It is generally pure black in appearance and it has very high magnetic flux density. Core loss of it is much smaller than that of iron powder core. So it is an economical and practical energy storage material with high cost performance ratio. Its main characteristics are that compared with iron powder core, it has low loss and good DC bias current characteristics. It can replace iron powder core and it has stable performance under high temperature conditions. Sendust core can work in the range of - 55 ~ 125 ° C without thermal aging, and it has high reliability in temperature resistance, humidity resistance and vibration resistance.

    Iron powder core

    Iron powder cores are generally painted with two colors, usually yellow-white, yellow-red, green-blue and green-red. Its main materials are carbon based iron powder and resin carbon based iron powder. It is a kind of core with very low permeability, generally 20-100. Because of this, the iron powder core is not easy to be saturated under the condition of high differential mode current, so it can be used to make differential mode inductor to suppress the differential mode interference of power line conduction. The frequency band of differential mode inductance filter made of iron powder core is very low, only at kHz level.

    Amorphous core

    The amorphous core is very "young". This material appeared in the late 1970s. It is environmentally friendly and efficient, and it has excellent magnetic properties. Therefore, compared with other cores, the price is higher. Amorphous cores are characterized by high saturation magnetic induction strength, low coercivity and low loss, as well as very high permeability, which is even much higher than that of manganese-zinc ferrite core. This type of core is often used to make common mode inductor to suppress low-frequency conduction interference. Compared with the manganese-zinc ferrite core, due to the much higher permeability, the inductor size can be made smaller. Amorphous core is supported by the plastic shell, so it is easy to recognize according to appearance.