Common Mode Intermediate Choke

A common mode signal is a signal that is present and equal on all conductors.  This may occur with radiated signals coupled to both lines of a circuit, an offset created from a driver circuit, or a ground differential between sending and receiving locations of a transmission system.  Noise, for example, usually occurs in common mode.  Likewise, Radio Frequency Interference being transmitted from a cable will emanate from all conductors.  This Common Mode Intermediate Choke filters out such undesirable signals.