The Definition of ElectroMagnetic Compatibility

EMC can be approached in two ways: before the fact— designing for EMC; or after the fact—patch work/clean up, Band Aids. Of course, designing in EMC safeguards ahead of time is always best; however, sometimes even the "best" designs aren't enough, and require some Band-Aids. Thus the "ART" aspect of EMC.

With the proliferation of electronic systems in every aspect of our daily lives, there inevitably comes the problem of compatibility. Listening to the news on AM radio while using an electric razor shouldn't be a problem, thanks to EMC design practices on the part of the razor manufacturer. The three constituents of EMC are [unwarranted] Emissions, [inappropriate] Susceptibility, and the [unintended] Pathbetween them. The electric razor's motor brushes arcing is a case of unwarranted Emissions; and the AM radio's picking up the noise through the Path(s) (power line, and/or through the air), is the unnecessary Susceptibility. Path consists of Radiated and Conducted energy. 1. Radiated (electromagnetic field)  2. Inductively coupled (magnetic field)  3. Capacitively coupled (electric field)  4. Conducted (electric current) Inductively coupled (magnetic field) Inductively coupled, (magnetic field) Capacitively coupled (electric field) Capacitively coupled W/Shield (electric field) Microstrip Transmission Line Characteristic Impedance affected by ground plane proximity: Z = High Microstrip Transmission Line Characteristic Impedance affected by ground plane proximity: Z = Low Raul Contreras CI : 19596032 EES secc: 02 fuente: http://www.williamson-labs.com/480_emc.htm