Iron Silicon Aluminum Blower Inductors

Iron Silicon Aluminum Blower Inductors

The common mode inductor is essentially a bidirectional filter: on the one hand, it filters out the common mode electromagnetic interference on the signal line, on the other hand, it inhibits the electromagnetic interference itself, so as to avoid affecting the normal operation of other electronic equipment in the same electromagnetic environment.

Why are common mode inductors EMI proof? To figure this out, we need to start with the structure of the common mode inductor.

The filter circuit of common mode inductor, La and Lb are common mode inductor Coils. The two coils are wound around the same iron core with the same number of turns and the same phase (the winding is reversed). In this way, when the normal current in the circuit flows through the common mode inductor, the current will generate the reverse magnetic field in the inductor coil wound at the same phase and cancel each other out. At this time, the normal signal current is mainly affected by the coil resistance (and a small amount of damping due to leakage). When there is a common mode current flowing through the coil, due to the co-directivity of the common mode current, the magnetic field in the same direction will be generated in the coil and the inductance of the coil will be increased, so that the coil will show high impedance and produce strong damping effect, so as to attenuate the common mode current and achieve the purpose of filtering.