1. The effect of the flat runway type magnetic ring is related to the circuit impedance

In the product manual of general ferrite materials, the insertion loss of the ferrite material is not given, but the impedance of the ferrite material is given. The greater the impedance of the ferrite material, the better the filtering effect.

2, the impact of the track type magnetic loop current

When a large current flows through the wires passing through the ferrite, the low-frequency insertion loss of the filter becomes small, and the high-frequency insertion loss does not change much. To avoid this, when using the power cord, you can pass the power cord and the power return line through the ferrite at the same time.

3. Selection of track-type magnetic ring ferrite materials

Ferrite materials of different magnetic permeability are selected depending on the frequency at which interference is to be suppressed. The higher the magnetic permeability of the ferrite material, the higher the impedance of the low frequency and the lower the impedance of the high frequency.

4. Determination of the size of the track-type magnetic ring ferrite magnetic ring

The larger the difference between the inner and outer diameters of the flat magnetic ring, the longer the axial direction, and the greater the impedance. But the inner diameter must be wrapped around the wire. Therefore, in order to obtain a large attenuation, a large-volume magnetic ring is used as much as possible under the premise that the inner diameter of the ferrite magnetic ring is wrapped.

5, the number of turns of the common mode choke coil of the track type magnetic ring

Increasing the number of turns through the magnetic ring increases the impedance of the low frequency, so in many applications, by winding more turns, the impedance can be effectively increased to achieve the desired effect. However, as the parasitic capacitance increases, the impedance of the high frequency decreases. When the interference band to be suppressed is wide, different turns can be wound on the two magnetic rings.

6. The number of ferrite flat magnetic rings on the runway type magnetic ring cable

Increasing the number of ferrite flat magnetic rings on the cable can increase the impedance of the low frequency, but the impedance of the high frequency will decrease. This is because of the increase in parasitic capacitance.

7. Installation position of the runway type magnetic ring ferrite flat magnetic ring

Generally as close as possible to the source of interference. For the cable on the chassis, the magnetic ring is as close as possible to the inlet and outlet of the chassis cable.

8. Runway type magnetic ring works better with capacitive filter connector

Since the effect of the flat track type magnetic ring depends on the impedance of the circuit, the lower the impedance of the circuit, the more obvious the effect of the magnetic ring. Therefore, when the capacitive filter connector is installed at both ends of the original cable, the impedance is low, and the effect of the magnetic ring is more obvious. The ferrite core coil is still an inductor at a lower frequency. For a filter circuit composed of such a single inductor, the cutoff frequency is: Fco = 1 / (2πRsL), and Rs is the original circuit impedance and load circuit. The series value of the impedance.