The role of inductance

The basic functions of the inductor are filtering, oscillation, delay, notch, and so on. The statement in the image is: "through DC, blocking communication."

In detail, it is in the circuit board, the inductor coil acts on the AC finite current, and it can form a high-pass or low-pass filter, a phase shift circuit and a resonant circuit with a resistor or a capacitor; the transformer can be AC-coupled, Transformer, converter and impedance transformation. The inductor coil is also an energy storage component that stores electrical energy in the form of magnets. The amount of stored energy can be expressed as: WL = 1/2 Li2. It can be seen that the larger the inductance of the coil, the larger the flow, and the more energy is stored.

Therefore, the most common role of the inductor in the circuit is to form an LC filter circuit together with the capacitor.