Three rules of EMC

Three rules of EMC

1) Rule 1. The law of EMC cost-effectiveness ratio: The earlier EMC problems are considered and resolved, the smaller the cost,and  the better the effect.

2) Rule 2: The larger the high-frequency current loop area S, the more serious the EMI radiation.

3) Rule 3. The higher the loop current frequency f, the more serious the EMI radiation caused, and the electromagnetic radiation field strength increases in proportion to the square of the current frequency f.

Three Elements of EMC Problem

Switching power supplies and digital equipment have high-frequency harmonics due to pulse current and voltage, so strong radiation will be generated. Electromagnetic interference includes radiated (high-frequency) EMI and conducted (low-frequency) EMI, that is, EMC problems are mainly generated through two ways: one is in the form of space electromagnetic interference; the other is in the form of conduction, in other words, The three elements of the EMC problem are: electromagnetic interference source, coupling path, and sensitive equipment.