Inductor (Inductor) is a component that can convert electrical energy into magnetic energy and store it. The structure of the inductor is similar to a transformer, but there is only one winding. When the inductor is in a state where there is no current flowing through it, it will try to prevent the current from flowing through it when it is turned on; in the state where there is current passing through, it will try to keep the current unchanged when the circuit is turned off.
 

Inductors mainly play the role of filtering, oscillation, delay and notch in the circuit, as well as screening signals, filtering noise, stabilizing current and suppressing electromagnetic wave interference. The most common role of inductance in the circuit is to form an LC filter circuit with the capacitor, which has the function of "through DC, blocking AC".

1. Symbol of inductance in the circuit: L;

2. Inductance unit: Heng (H), milliHen (mH), micro Heng (μH);

3. The conversion relationship is: 1H = 10 ^ 3mH = 10 ^ 6μH = 10 ^ 9nH.

According to the working frequency classification: divided into high frequency inductance, medium frequency inductance, low frequency inductance.

According to the structure: fixed inductance, adjustable inductance.

Classification by function: filter inductance, choke inductance, oscillation inductance, isolation inductance, etc.

According to the packaging form: chip inductors, plug-in inductors.