Label：High Frequency Transformer, Magnetic Cores, Iron Powder Core, AC Inductors
Aug 18, 20229220
Hi guys, this is JRPanel ! In previous blogs, we have introduced several points about High Frequency Transformer, like bobbins and Flat Spiral Coil. In this blog, JRPanel would like to introduce the commonly used magnetic cores in transformers, based on materials.
Generally speaking, the material of the core determines the environment in which the transformer is used. A transformer that uses a core of a different material will have its performance affected, may even be non-functional.
By material, magnetic cores are generally divided into the several categories. JRPanel will introduce them one by one to help you understand more fully.
Mn-Zn core is a soft magnetic core with high initial permeability (2000~15000). The higher the initial permeability, the lower the surface resistance, so it is generally used in circuits below 1 MHz. Mn-Zn core has a high saturation flux density and causes lower losses, making it one of the most desirable core for power inductors around 100 KHz.
Ni-Zn core is a soft magnetic ferrite core with an initial permeability of 5~1500. Due to its high surface resistance (more than 100M ohms), this core is generally used on medium to high frequency circuits. This type of core also causes low loss and is characterized by low temperature coefficient, high Curie Temperature and good high frequency characteristics.
Also, due to the large saturation flux, it can be used for magnetic bar inductors, some I-shaped inductors and axial inductors.
Iron powder core is one of the most common soft magnetic materials and one of the less costly materials on the market today. This material consists of carbon-based ferromagnetic powder and resin carbon-based ferromagnetic powder. Due to the low price, iron powder cores are still the most used magnetic powder cores.
High flux powder cores are the more common cores in China today, and are the materials with the strongest resistance to DC bias. It is very popular among manufacturers. The magnetic permeability of this powder core varies, and the loss of the core is similar to that of iron powder core, but much larger than that of iron-silicon aluminum.
This type of cores are mainly used in high DC bias, large DC and low frequency AC circuits, also in line filters, AC inductors, output inductors, power factor correction inductors, etc.
Ferrosilicon aluminum core is also a commonly used soft magnetic material, which is mainly made of pure iron and silicon and aluminum. Due to the addition of silicon and aluminum to pure iron in the fabrication process, the hysteresis coefficient of the material is close to zero. This reduces the material's ability to convert electromagnetic energy into mechanical energy, resulting in lower losses in the iron-silicon aluminum powder core than in the iron powder core.
The ferrosilicon aluminum powder core has a stronger resistance to DC bias than the iron powder core. Since it does not contain organic components, this powder core does not deteriorate.
Molybdenum Permalloy core is one of the most expensive magnetic powder cores, and is also a soft magnetic material with a high nickel content.
It has a low saturation magnetic induction, a wide range of permeability variation, and a hysteresis coefficient close to 0. It is excellent in terms of temperature stability, so this material also has the lowest core loss among magnetic powder cores.
In addition, molybdenum pozzolanic powder cores are second only to Ferrosilicon Aluminum powder cores in terms of resistance to DC bias. In summary, the advantages of this core are remarkable.
If you are still confused about transformer cores, please do not hesitate to contact us !