How to choose a common mode inductor core?
How to choose a common mode inductor core?,
,
Power line CM chokes achieves high suppression of asymmetric interferences, even at low frequency ranges. Do not underestimate the parasitic effects when using common mode chokes. This was the most important point to reduce these dues when developing the WE-CMB series. The perfect core / winding-ratio enables very-high currents at comparable areas, anyhow the inductance is sufficient. The adjusted wire gauge realizes low heating.
Advantages:
1. Very compact design
2.Customized the product according to the basic information from your engineers. Quick sample lead time.
3.High levels of safety and reliability
4. Filtering common mode electromagnetic interference signals
5.Useful for application requiring inductance to vary with current load changes.
6.Self electromagnetic shielding. Easy PC board mounting Conversion application.
7.Build to ROHS compliance.
Autually the common mode inductor is essentially a two-way filter: on the one hand, it must filter out common mode electromagnetic interference on the signal line, and on the other hand, it must suppress itself from emitting electromagnetic interference to avoid affecting the normal operation of other electronic equipment in the same electromagnetic environment.
Common-mode inductors have extremely high initial permeability, large impedance and insertion loss under the earth’s magnetic field, and have an excellent suppression effect on interference, and exhibit resonance-free insertion loss characteristics in a wide frequency range. High initial permeability: 5-20 times that of ferrite, so it has greater insertion loss, and its suppression effect on conduction interference is much greater than ferrite.
Size and dimensions:
|
Item |
A |
B |
C |
D |
E |
F |
G |
|
Size(mm) |
14 Max |
10.5Max |
16Max |
3.5±0.5 |
4.5±0.3 |
10±0.3 |
0.7±0.2 |
Electrical properties:
|
Testing item |
Standard |
|
|
Inductance |
WL W2 |
1.95111H Min@10KHz 0.05V SER @25°C |
|
Dotted terminals |
1.4 |
|
|
Turn ratio |
Wl, W2 |
1:1 |
|
Hi-Pot |
Wl. W2 |
No breakdown 1000XAC 2mA 2S |
Application:
1.Power electronics.
2.Power line in and output filter, switching power supply.
3.Power-line input and output filter
4. Suppression of radio interferences in motors
5.TV and audio equipment, buzzers and Alarm systems.
6. Optimized for burst signals
7.Radio interference suppression in motorsWhen selecting a magnetic core for a common mode inductor, the shape, size, applicable frequency band, temperature rise and price must be considered. Commonly used magnetic cores are U-shaped, E-shaped and toroidal. Relatively speaking, toroidal cores are cheaper because only one toroid can be made. Other shapes of magnetic cores must have a pair to be used for common mode inductors, and when forming, considering the pairing of the two magnetic cores, it is necessary to increase the grinding process to obtain higher magnetic permeability. So; compared with other shapes of magnetic cores, toroidal cores have higher effective magnetic permeability, because when two pairs of magnetic cores are assembled, the phenomenon of air gap cannot be eliminated no matter how the operation is performed, so the effective magnetic permeability is higher than that of a single closed-shaped magnetic core. The core should be low.
