What are the uses of inductors?

Inductor in the circuit mainly plays the role of filtering, oscillation, delay, notch and so on, but also screen signal, filter noise, stable current and suppress electromagnetic interference and so on. The most common role of inductor in circuit is to form LC filter circuit together with capacitor. Capacitance has the characteristic of "DC resistance, AC resistance", while inductor has the function of "DC resistance, AC resistance". If the DC with many interference signals is passed through the LC filter circuit, the AC interference signals will be converted into heat energy by the inductor and consumed; When the pure DC current flows through the inductor, the AC interference signals are also changed into magnetic induction and heat energy, and the ones with higher frequency are most likely to be impeded by the inductor, which can suppress the interference signals with higher frequency.

An inductor has the property of preventing alternating current from passing through while allowing direct current to pass through. The higher the frequency, the higher the coil impedance. Therefore, the main function of the inductor is to isolate and filter the AC signal or form a resonant circuit with capacitors, resistors, etc.