| | Q: Why must we achieve EMC?
A: Other than the fact that products which do not comply cannot be marketed legally in the EC, more disruptive manifestations exist that can affect the way in which we lead our lives. These encompass health and safety issues, the security of data processing, and the functioning of electronic equipment. ABS braking systems, engine management systems, telecommunications and data transfer plus the security of both commercial and military data could all be readily compromised without adequate screening. |
| | Q: What are the main sources of EMC problems ?
A: In all cases there has to be a source and a victim for a path to exist thereby permitting a radiated or conducted coupling. RF interference (sometimes referred to as RFI), more correctly known as Electromagnetic Interference (EMI), results from the operation of electrical or electronic devices involving rapidly changing voltage or current levels and which cause the generation of electromagnetic energy at discrete frequencies and over frequency bands. |
| | Q: What are some sources of electromagnetic emissions (EME)?
A: There are two main sources of emissions: Radiated Emissions (Examples: power lines, pulsed circuits, and improperly designed electronic systems). Conducted Emissions (Examples: switching transients, motor noise on the power lines, RF on the power leads). |
| | Q: What is conducted interference?
A: These interference signals move from one point to another on the power supply leads between a source and a receptor. Two possible sources of these signals are (1) the circuits within the device and (2) radiated energy induced onto the wires of the device. |
| | Q: What is radiated interference?
A: Radiated Interference: These interference signals are transferred via an electromagnetic (EM) field produced by a signal source over a propagation path through the air. The source of these signals can be external (e.g., radio and TV stations) or internal (e.g., unshielded radio frequency (RF) circuits and switching power supplies) to an electronic system. |
| | Q: What is EMC?
A: Electromagnetic compatibility is an essential feature of any specification for electrical equipment. It is defined as the ability of electrical and electronic equipments, sub-systems and systems to share the electromagnetic spectrum and perform their desired functions without unacceptable degradation from or to the specified electromagnetic environment. |
