What is SQ Flat Wire Common Mode Inductor?

SQ Flat Common Mode Inductor Principle:

When the common mode current flows, the magnetic fluxes in the magnetic ring are superimposed on each other, so that they have a considerable inductance, which inhibits the common mode current. Cancellation, there is almost no inductance, so differential mode current can pass through without attenuation. Therefore, the common mode inductance can effectively suppress the common mode interference signal in the balanced line, but has no effect on the normal transmission of the Jammu signal.

Common mode inductors should be changed to meet the following requirements during production:

The wires wound on the magnetic core of the coil should be insulated from each other to ensure that no breakdown short-circuit occurs between the turns of the coil under the action of instantaneous overvoltage.
When the coil flows through a large instantaneous current, the magnetic core should not be saturated.
The magnetic core in the coil should be insulated from the coil to prevent the two from breaking down under the action of transient overvoltage.
The coil should be wound in a single layer as much as possible, which can reduce the parasitic capacitance of the coil and enhance the coil's ability to withstand transient overvoltage.
Depending on the direction of propagation, power supply noise can be divided into two categories:

One is the external interference introduced from the power line, and the other is the noise generated by the electronic equipment and conducted through the power line. This shows that the noise is a two-way interference signal, and the electronic equipment is both the object of the noise and the source of interference.

Series mode interference: ground noise between two power lines, differential mode interference. Below 200HZ
Common Mode Interference: Two power lines to earth ground noise. Above 1MHZ

Therefore, the electromagnetic interference filter should meet the requirements of electromagnetic compatibility, and must also be a two-way radio frequency filter. interference.

The common mode inductance L has no effect on the series mode interference, but when the common mode interference occurs, since the two coils have the same magnetic flux direction, the total inductance increases rapidly after coupling, so it presents a large inductive reactance to the common mode signal, It is not easy to pass through, so it is called a common mode choke coil. Its two coils are respectively wound on low-loss, high-permeability ferrite magnetic rings. When there is current passing through, the geomagnetic field on the two coils will strengthen each other. The inductance of L is related to the rated current of the EMI filter.

X capacitors, with a capacity range of 0.01mf-0.47uf, are mainly used to filter out series-mode interference. The Y capacitor is connected to the output end, and the midpoint of the capacitor is grounded, which can effectively suppress common mode interference. The value range is 2200pf-0.1uf. In order to reduce leakage current, the capacitance should not exceed 0.1uf.

FKS COILS provides various types of SQ flat common mode inductors with low price and good quality, welcome to contact us.