1 anti-jamming magnetic ring magnetic rings better

2 combination of aperture and through cable as closely as possible.

3 low frequency end harassment, we recommend cables around 2~3 turns, high end harassment, not turn-around (because the existence of the distributed capacitance selection long magnetic loops.

Usually in electronic equipment power or signal cables at one end or both ends to see magnetic ring is common-mode choke coil. Common mode choke coil impedance of common mode interference currents can be larger, and has no effect on differential mode signal (signal to differential mode signals) so simple regardless of the signal distortion. And common mode choke coil does not need grounding, can be added directly to cable.

Select a whole bunch of turns of the magnetic loop cable through a Ferrite ring constitutes a common-mode choke coils, depending on your needs, can be on the magnetic ring wrap a few turns of the cable. Turns the more interference suppression for low frequency effects, the better, but weak inhibition of high frequency noise. In practice, interference current according to the frequency characteristics to adjust the number of turns of the magnetic ring. Usually when interference signals with wide frequency band can put two magnetic rings in the cable, each surrounded by different number of turns, which can inhibit high-frequency disturbances and low frequency interference. Seen from the mechanism of common mode choke coil, its impedance greater interference suppression effect more obvious. Impedance of common mode choke coil Lcm=jwLcm from common-mode inductor is not difficult to see from the formula, for a certain frequency noise interference magnetic inductance of bigger is better. But this is not the case, because the actual anti-jamming magnetic rings also have parasitic capacitance, there is parallel with the inductor. When it comes to high-frequency interference signals, the capacitive reactance of the smaller, anti-jamming magnetic inductance of short circuit, so that the common mode choke coil loses effectiveness.