Analysis of the Quality of Common Mode Inductor Materials 1

Let's start with the magnetic ring type:

Core material: mainly nanocrystalline; wire material: not discussed here;

Advantages of the iron core:

High initial permeability (a fundamental requirement for common-mode inductors), high saturation magnetic flux density, temperature stability superior to ferrites (interpreted as minimal temperature rise), flexible frequency characteristics, and the ability to achieve large inductance with minimal material due to high permeability, supporting a wide range of frequencies;  diode

Overall Advantage:

Since the initial permeability is 5-20 times that of ferrite, its suppression effect on conductive interference far exceeds that of ferrite;

The high saturation magnetic flux density of nanocrystalline materials is superior to that of ferrites, making them less prone to saturation under high currents;

The temperature rise is lower compared to the UF series. Based on my actual testing: it is nearly 10 degrees lower at room temperature (personal test values are for reference only);

The structural flexibility ensures excellent adaptability, allowing it to meet diverse needs through modifications in processing techniques (as seen in the flexible application of toroidal inductors in energy-saving lamps)

The distributed capacitance will be smaller, as the winding area is wider and the volume is relatively smaller

The ring winding uses fewer turns and has smaller distribution parameters, resulting in higher efficiency (specific analysis is needed, I suspect it's due to the wire diameter, but further details are required);

Overall disadvantage:

The small aperture of the magnetic ring makes it difficult for machines to thread, requiring manual winding, which is time-consuming, labor-intensive, and results in high processing costs and low efficiency. As cost pressures continue to mount, this issue has become particularly critical.diode