Electromagnetic interference (EMI) within the domestic environment.

The number of electrical appliances used in the domestic environment is increasing, and so is their diversity. Household appliances, communication systems and audiovisual equipment all coexist in the same place. Individually, each one complies with standards limiting, among other things, the level of electromagnetic disturbance. All these devices incorporate energy converters based on power electronics. The simplest conversions, such as rectifiers with capacitive filtering, deteriorate the quality of the current consumed, distorting the voltage of the electrical network and disturbing sensitive systems connected to it. The contribution of power electronics in this field has made it possible to reduce the size of power supplies, improve their efficiency and make them more reliable. They can also absorb very slightly distorted currents. These systems use semiconductors controlled in "on/off" mode, which has the advantage of reducing conduction losses, unlike the use of bipolar transistors in linear mode in older ballasts. This switching mode significantly improves efficiency. However, this switching produces harmonics linked to the switching frequency of the switches. Because of their wide spectrum, these switches can pose electromagnetic compatibility (EMC) problems, despite compliance with standards.

Switching is one of the most influential parameters in the EMC design of power converters. This is a source of interference common to all converters, from dimmers to switch-mode power supplies supplying the DC voltage needed to operate the electronics of various household appliances. In a dimmer switch, the frequency of voltage switching is low, but sufficient to interfere with the "long wave" range of radio or digital systems. In the new compact fluorescent lamps, this switching frequency is higher. The use of these lamps brings a new source of electromagnetic disturbance into the domestic environment, both conducted on the power grid and radiated into the lamp environment.