What Is A Chip Common Mode Choke | GETWELL

Are there patches for common mode inductors?This should be a lot of customers and buyers of the doubt?The common mode choke manufacturer Getwell will answer the common mode choke in the end there is no patch;

We need to understand how it works;Common mode inductors have high initial permeability, large impedance and insertion loss in geomagnetic field, good interference suppression, and non-resonant insertion loss in a wide frequency range.

common mode choke is very common in daily life. In the application of computers, there are various high frequency circuits, digital circuits and analog circuits mixed on the computer's internal motherboard. When they work, they produce a large number of high frequency electromagnetic waves and interfere with each other, namely EMI.Electromagnetic interference will also be emitted outward through the conductor or external cable on the motherboard, causing electromagnetic radiation pollution, not only affect the normal work of other electronic equipment, but also harmful to human body.

Are there patches for common mode inductors?

This depends on the common mode choke.It is similar in structure and function to the upright type because of a chip common mode inductor.

common mode choke coils consist of conductors winding round and round on insulating tubes, which are insulated from each other. The insulating tubes can be hollow or contain an iron core or magnetic powder core, which is referred to as inductance.In L, the units are Henry (H) and milliHenry

(mH), micro Henry (uH), 1H=10^3mH=10^6uH.

Classification of common mode inductors.

Classified by inductance form: fixed inductance, variable inductance.

Classified according to the properties of magnetic conductor: hollow coil, ferrite coil, iron coil, copper coil.

Classified by the nature of work: antenna coil, oscillating coil, choke coil, trap coil, deflection coil.

Classified by winding structure: single-layer coil, multi-layer coil, honeycomb coil.

Main characteristic parameters of inductance coil:

1.Inductance L

Inductance L represents the inherent characteristics of the coil itself, independent of the common mode current size.Except for special inductance coils (color code inductors), the inductance is generally not marked on the coil, but by a specific name.

2.inductive XL

The size of the inductance coil on the AC current obstruction is called inductive reactance XL, the unit is ohm.Its relation to the inductance L and the alternating current frequency F is XL=2πfL

3.Quality factor Q

Quality factor Q is a physical quantity representing the coil quality, Q is the ratio of inductive resistance XL and its equivalent resistance, that is: Q=XL/R.

The higher the Q value of the coil, the smaller the loss of the loop.The Q value of the coil is related to the DC resistance of the wire, the dielectric loss of the skeleton, the loss caused by the shield or iron core, and the influence of the skin effect at high frequency.The Q value of the coil usually ranges from tens to hundreds.

4.distributed capacitance

The capacitance between the coil turns and turns, between the coil and the shield, between the coil and the plate is known as the distributed capacitance.The existence of distributed capacitance reduces the Q value of the coil and makes the stability worse. Therefore, the smaller the distributed capacitance of the coil, the better.

Common mode inductors commonly used coils are:

1.Single layer coil

A single layer coil is made of insulated wire wound round and round on a paper tube or bakelite frame.Such as transistorized radio medium wave antenna coil.

2.Honeycomb coil

If a coil is bypassed, its planes are not parallel to the surface of rotation, but intersect at an Angle defined by Yi. This is called a honeycomb coil.And the number of times the wire bends back and forth after it has rotated once, is usually called the number of bending points.This method has the advantages of small volume, small distributed capacitance and large inductance.The honeycomb winding machine is used to wind the coils in the honeycomb. The more the folding points, the smaller the distributed capacitance.

3.Ferrite core and iron powder core coil

The inductance of the coil is related to the presence or absence of magnetic core.Inserting a ferrite core into the hollow coil can increase the inductance and improve the quality factor of the coil.

4.Copper coil

The copper core coil is widely used in the ultrashort wave range. The position of the copper core coil is rotated to change the inductance, which is convenient and durable.

5.Color code inductor

The color code inductor is an inductor with fixed inductance, and its inductance is marked by color ring as the resistance.

6.Choke coil (choke coil)

The coil that restricts the flow of alternating current is called the choke coil, which is divided into high frequency choke coil and low frequency choke coil.

7.Deflection coil

Deflection coil is the output load of TV scanning circuit. Deflection coil requires high deflection sensitivity, uniform magnetic field, high Q value, small size and low price.

The above is the knowledge of SMT common mode choke, hope to help you to some extent.We are the inductor supplier from China - Getwell Electronics.If you do not understand, welcome to consult us!