EMI / Electrical Noise
Electrical noise, also called electromagnetic interference, or EMI, is unwanted electrical signals that produce undesirable effects and otherwise disrupt the control system circuits. EMI may be either radiated or conducted. When the noise originates from a source and travels through the air it is called radiated. Radio and TV signals can radiate EMI. Conducted noise travels on an actual conductor, like a power line. The original noise may have been radiated, coupled into the lines, then conducted.