Common mode choke is an important component of devices such as switching power supplies, frequency converters, UPS power supplies, etc. Working principle of inductor: When the working current flows through two coils wound in opposite directions, two magnetic fields H1 and H2 that cancel each other out are generated. At this time, the working current is mainly affected by the damping of the coil ohmic resistance and the negligible small leakage inductance at the operating frequency. If there is interference signal flowing through the inductor, the inductor will exhibit high impedance and produce strong damping effect, thereby attenuating the interference signal.

1. Detailed explanation of the working principle, function, characteristics, and application of common mode choke:

Common mode choke is an important component of devices such as switching power supplies, frequency converters, UPS power supplies, etc. Its working principle: When the working current flows through two coils wound in opposite directions, two mutually canceling magnetic fields H1 and H2 are generated. At this time, the working current is mainly affected by the damping of the coil ohmic resistance and the negligible small leakage inductance at the operating frequency. If there is interference signal flowing through the coil, the coil will exhibit high impedance and produce strong damping effect to attenuate the interference signal.

2. Function of common mode choke:

The common mode choke coil is essentially a bidirectional filter: on the one hand, it needs to filter out common mode electromagnetic interference on the signal line; On the other hand, it is necessary to filter out common mode electromagnetic interference on the signal line. On the other hand, it is necessary to suppress the emission of its own electromagnetic interference to avoid affecting the normal operation of other electronic devices in the same electromagnetic environment. The common mode choke can transmit differential mode signals, and both DC and low-frequency common mode signals can pass through. At the same time, it presents a large impedance to high-frequency common mode noise and can be used to suppress common mode current interference.

3. Characteristics of common mode choke:

The common mode choke coil adopts ferrite core and double wire winding, which has high common mode noise suppression and low differential mode noise signal suppression capabilities. It is not easily deformed in high-speed signals, has a small size, is easy to use, has excellent balance, is easy to use, and has good quality. In addition, it has a low impedance in the operating frequency band, a high impedance in the interference frequency band, stable inductance value, good thermal stability, and a variety of structural forms and impedance characteristics to choose from. 

Daily application of common mode choke:

1. Switching power supply noise suppression filter

2. Static noise filters for power and signal lines

3. Radiation interference suppressors such as converters and ultrasonic equipment.