There are two kinds of Electro Magnetic
Interference (EMI), referred by unwanted interference energies conducted
as currents or radiated as electromagnetic fields. Agencies, such as Federal
Communications Commission (FCC) and Verband Deutscher Elektrotechniker (VDE),
have established rules governing EMI emissions. It is important for engineers
to filter noise or eliminate ground loops. If resolved at the early fan
design level, a simple by-pass capacitor or ferrite bead can improve the
EMI problem.
