General electromagnetic core knowledge

◆how to test inductance Al? Why must be conducted in 5 gauss test?

The Inductance will be change follow voltage and frequency on the bridge, Magnetic flux density should be less than 10 gauss. The core correctly placed around the package online, or use the toroidal cores, But should ensure the number of turns right. In the lower level of gauss test is very important, the magnetic material will be change with powder increase. For a variety of different applications, we must keep the product conformity at low level of gauss, this is "similar comparative".

◆Why toroidal cores must have a corner radius

Corner radius is important for toroidal cores, because of corner radius May be broken wires in the operation of precision winding insulation. To make sure this, We have done a lot of work. the pressure mold has a built-in radius, Magnetic core sharp edges were polished. So after coating, Not only has more blunt corner radius, and wound surface more smooth.

◆Whether can reduce magnetic core size tolerance

In the operation of sintering, core shrinks to the final size. Materials and processing technology of different will cause the skew linear shrinkage rate, the range for the size of 10% to 20%, After sintering dimension deviation caused by the minimum tolerance range is 1-4%. Some can't control in a smaller size range, and the size can be processed for the after sintering, To ensure that in a smaller range of tolerance.

◆the Parylene can be used toroidal cores?

Parylene is a kind of vacuum deposition coating; it has good resistance to moisture and organic solvent properties, Electric property is superior to the other coatings. Because of this is an expensive coating, so the coating limit within the scope of 20 mm or smaller in diameter, and to save money.

◆the core parameters effectively

Magnetic core has a variety of geometric shapes, in order to application adopted in the many formula, we calculate the core physical parameters to minimize geometrical effects, and these parameters include the length of the magnetic circuit, the effective cross-sectional area and volume effectively.

◆Use what kind of material is best

There is no general answer to this question, to choice material depends on the applications and frequency, Choose any material is a kind of compromise. For example, some materials have good temperature stability, but expensive. But if you can bear the temperature, May be large and cheaper materials cores can be competent. The best material choice depends on application to the inductor or transformer. Starting from this point, the operating frequency and the cost is also very important. Different materials suitable for different frequency range, operating temperature and magnetic flux density. The choice of the magnetic core narrowed down to a particular type, suggest try different magnetic core, and then make a final choice.