Introduction to common mode inductors

Introduction to common mode inductors A common mode inductor, also called a common mode choke, is a coil with the same direction and the same number of turns wound on a closed magnetic ring. Common-mode inductors can suppress common-mode interference, but have no inhibition on differential mode signal. Working principle When a differential mode current flows through a common mode inductor, two magnetic fields cancel each other out. If a common-mode interference signal flows through the coil, a mutually reinforcing magnetic field is generated between the two groups of coils, so that the entire coil presents a high resistance state to attenuate the interference signal. A. When the normal current in the circuit flows through the common mode inductor, the current produces a reverse magnetic field in the inductor coil wound in the same phase and cancles each other out, and the normal signal current is mainly affected by the coil resistance (and a small amount of damping caused by lea…