EMC Competence

Electromagnetic compatibility as a basic requirement
Power supplies separate the mains supply (e.g. 230 Vac or 3×400 Vac) from any low voltages created (e.g. 5 Vdc, 12 Vdc). They must ensure safe electrical separation and comply with the statutory requirements in terms of EMC. Power supplies must also be able to withstand extreme conditions and be immune against external interference, as well as protecting connected appliances, such as sensitive electronic modules.

When developing the first generation of MGV switch-mode power supplies between 1981 and 1983, control of emission and immission was a major issue, even long before EMC legislation and CE conformity came into force. Today we ensure that our power supplies offer especially high resistance and are equipped for daily use by incorporating certain immission values that are in some cases far above required standards.

Tested in our own EMC laboratory

For many years, we have been testing the electromagnetic compatibility of both our power supplies and DC/DC converters in our own laboratory. This includes:


  • Conducted interference according to EN55011 and 55022
  • Radiated emission according to EN55011 and 55022
  • Parasitic current measurement according to EN55011 and 55022
  • Harmonics according to EN 61000-3-2 and EN61000-3-12


  • Surge according to EN 61000-4-5
  • Burst according to EN 61000-4-4
  • VDE0160 (German Association for Electrical Technologies)
  • ESD according to EN 61000-4-2
  • Immunity against electrical fields EN 61000-4-3

The layout and topology of switch-mode power supplies have a direct impact on their electromagnetic behaviour. We pay particular attention to this. Continuous testing during development allows us to take measures to optimise EMC by adjusting the design of printed circuit boards, the positioning of components and the filter design, as well as modifying the circuit technology to rule out potential interference from the very start.