Inductors and Magnetic Beads

Small Inductors in the circuit mainly play the role of filtering, oscillation, delay, trap, and so on, but also screen signals, filter noise, stabilize the current and inhibit electromagnetic wave interference. The most common function of inductors in circuits is to form LC filter circuits together with capacitors. The capacitor has the characteristic of "blocking DC, blocking AC", while the inductor has the function of "blocking DC, blocking AC". If the direct current accompanied by many interference signals is passed through the LC filter circuit,then the AC interference signal will be consumed by the inductance into heat energy; When the pure direct current flows through the inductor, the AC interference signal is also changed into magnetic induction and thermal energy, and the higher frequency is most easily impeded by the inductor, which can inhibit the higher frequency interference signal. 

Shielded inductor have the property of preventing the passage of alternating current and allowing direct current to pass smoothly, and the higher the frequency, the greater the coil impedance. Therefore, the main function of the choke electronics is to isolate and filter the AC signal or to form a resonant circuit with capacitors and resistors.