The term Electromagnetic Compatibility (EMC) covers all aspects of the interaction of electrical and electronic equipment with its electromagnetic environment and with other equipment.
Any electronic equipment can be affected by external disturbances: radio frequency fields, electrostatic discharge, conducted transient interference or supply voltage variations. Or it could generate its own interference emissions. Digital and microprocessor-based systems in particular, as well as power switching converters and electromechanical devices such as motors, create noise which affects radio reception and other sensitive equipment across the spectrum.
Good EMC design minimises both susceptibility to, and generation of, electromagnetic disturbances.
Why is it important?
Because of the threat to legitimate users of the radio spectrum, many countries limit the interference that equipment can generate. Perhaps your customers specify that their system performance must be maintained in the presence of electromagnetic interference. Even if they don't, you may have discovered an EMC problem with your equipment in a particular installation.
All products marketed within Europe should comply with the provisions of the various EMC-related Directives, which require both adequate immunity from interference and the control of emissions. The US have had emissions legislation for many years, Australia has implemented its Regulatory Compliance Mark, and other Far Eastern countries have taken up the same process. If you sell within any of these countries, or into other safety-critical industries such as transport or process control, your product's EMC performance is important.
But it's such a difficult subject...
There are many unknowns surrounding the question of EMC. What are the applicable standards and how do I find out about them? Which tests should I do and how do I do them? If the equipment doesn't pass the tests, what can I do about it? Most importantly, how do I design from the start so that it will pass the tests? You need answers to all these questions. That's where EMC consultants Elmac Services can help you.