Common Mode Choke

A common mode current choke, also known as a common mode inductor, is an important passive electronic component, mainly used to suppress common mode interference in electrical circuits.  When common mode current flows through the two windings, since the currents in the two windings are in the same direction, the magnetic fluxes generated in the magnetic core are superimposed on each other, resulting in a large inductance value. The coil then exhibits a high impedance, creating a strong damping effect that attenuates the common mode interference signal. This makes the common mode power line choke or common mode suppression choke highly effective for reducing electromagnetic interference (EMI) in power lines and signal lines.