EMI stands for ElectroMagnetic Interference, a compound term that encompasses two distinct concepts: electromagnetic and interference.
Understanding "Interference"
Interference can be understood in two ways:
- The degradation of equipment performance due to external influences
- The source that causes such interference
Real-Life Examples of EMI
Some common examples include:
- Radio static caused by lightning
- Screen distortion when motorcycles pass by
- Snowflake noise on a TV screen
- Hearing radio signals through a telephone
These are often referred to by abbreviations such as BCI (Broadcast Interference), TVI (Television Interference), and TelI (Telephone Interference). The common denominator is the "I", meaning interference.
How Electromagnetic Interference Occurs
Electromagnetic phenomena are generated in different ways:
- Static electricity: stationary charge buildup
- Electrostatic discharge (ESD): when charges at different potentials move, creating current
- Electromagnetic waves: caused by continuously changing currents and magnetic fields
Electricity manifests in many forms, and when these forms generate disturbance, we refer to them collectively as electromagnetic interference.