Electromagnetic Interference

This interference in the operation of a device is caused by incompatibility with ambient signals. Common sources of EMI include transmitters and receivers (radio, TV, cell phone), power mains (lightning, surges, brownouts), appliances, computer oscillators, and electrostatics.

Electromagnetic compatibility is the ability of two or more electronic or electrical systems or units to co-exist without either disturbing the correct operation of the other. If this situation does not exist then one unit is said to be interfering with the other. Measures need to be taken to limit this disturbance and these measures depend upon whether the unit is subject to conducted or radiated electromagnetic disturbance.

Where displays are concerned, interference occurs by the transmission of an interfering signal in the form of an electromagnetic wave and, for the frequencies with which we are usually concerned, are termed Radio Frequency Interference (RFI) or Electromagnetic Interference (EMI). In some cases the level of disturbance can be controlled by adjusting the electronic circuitry.