Most magnetic rings need to be sprayed, which is convenient and different. Generally, iron powder cores are distinguished by multiple colors. Common ones are red/full transparent, yellow/red, green/red, green/blue and yellow/white, and manganese cores. The ring is generally painted emerald green, and sendust is generally black. In fact, the color tone of the magnetic ring after firing has nothing to do with the color of the architectural paint that will be sprayed in the future. It is only a promise in the field. For example, green represents high permeability magnetic ring; two colors represent iron powder core magnetic ring; black represents sendust magnetic ring, as shown in the figure
(1) High permeability ring
High permeability magnetic ring, you have to admit the nickel-zinc ferrite magnetic ring. Magnetic rings are divided into nickel-zinc and manganese-zinc according to the raw materials. The magnetic permeability of nickel-zinc ferrite magnetic ring raw materials varies from 15 to 2000 at this stage. The common raw material is nickel-zinc ferrite with a magnetic permeability of 100- Among 1000, it is classified according to magnetic permeability and divided into low-permeability raw materials. The magnetic permeability of the raw material of the manganese-zinc ferrite magnetic ring is generally above 1000, so the magnetic ring produced by the manganese-zinc material is called a high-permeability magnetic ring.
Nickel-zinc ferrite magnetic rings are generally used for various cables, circuit board ends, and anti-interference in computer equipment. Manganese-zinc ferrite magnetic rings can be made into inductors, transformers, filters, transformer skeletons, and magnetic tapes. Machine and wireless antenna rod. In general, the lower the permeability of the raw material, the wider the usable frequency range; the higher the permeability of the raw material, the narrower the usable frequency range.
(2) Iron powder core magnetic ring
The iron powder core is a simple name for the permanent magnetic material ferroferric oxide, which is mainly used in the control circuit of household appliances to deal with the problem of electromagnetic compatibility testability (EMC). In specific applications, various other chemical substances will be added according to the different filtering regulations under different stock bands.
The initial magnetic powder core is a soft magnetic transformer skeleton made of "bonded" metal material made of iron-silicon-aluminum alloy magnetic powder. Everyone often refers to this kind of sendust magnetic powder core as "iron powder core". Its typical preparation and processing technology is: use Fe-Si-Al aluminum alloy magnetic powder to go through the flat design of the ball mill to solve the problem, and use organic chemistry to carry out the cable sheath coating, and then add 15wt% of the adhesive, and mix and evenly. The post-compression mold is dry and solid, and is always made into a commodity through a heat treatment process (to eliminate internal stress). For this kind of traditional "iron powder core" products, the key work is between 20kHz and 200kHz. Because they have much higher saturation magnetic flux density than ferrites working in the same frequency range, good AC accumulation characteristics, magnetostriction index close to zero, no noise during operation, good frequency reliability, and characteristic price comparison High advantages, widely used in electronic components such as high-frequency electronic transformers. Their defect is that the non-magnetic filler not only causes the magnetic diluent, but also causes the magnetic flux channel to be unsustained, and partial demagnetization causes the magnetic permeability to decrease.
The recently developed and designed iron powder cores with excellent performance are different from the traditional sendust magnetic powder cores. The raw materials used are not aluminum alloy magnetic powders but pure fans coated with the cable sheath. The amount of adhesive used is very small, so The magnetic flux density is greatly improved. They work in the low and medium frequency bands less than 8kHz, generally several hundred HZ, which is much lower than the output power of sendust magnetic powder cores. The market positioning is to replace the ferrite core used in the motor with its advantages of no consumption, high efficiency and easy development of three-dimensional design.
(3) Sendust magnetic ring
Sendust magnetic ring is one of the magnetic rings with higher utilization. In simple terms, sendust is composed of aluminum-silicon-iron and has a very high Bmax (Bmax is the larger average value on the cross-section of the transformer skeleton. Flux density.), its transformer skeleton loss is much less than iron powder core and high magnetic flux, low magnetostriction (low noise), is a low-cost energy storage technology raw material, no thermal embrittlement, can be used to replace iron powder core , The characteristics are very stable at high temperatures.
The key feature of sendust is lower loss compared with iron powder core, and it has excellent DC bias current characteristics. The price is not very high, but it is not very low, compared with the iron powder core and the iron-nickel alloy molybdenum.
Sendust magnetic powder core has excellent magnetic tape magnetic energy, low output power loss, high magnetic flux density, and high temperature resistance, water resistance, earthquake resistance and high reliability when used in the temperature range of -55C~124C;
In addition, the wide permeability range of 60 to 160 can be cited. It is a better choice for power transformer output choke coils, PFC inductors and series resonant inductors, with high cost performance.