An inductor is a component that can convert electrical energy into magnetic energy and store it

An inductor is a component that can convert electrical energy into magnetic energy and store it. The structure of an inductor is similar to that of a transformer, but it only has one winding. An inductor has a certain inductance that only hinders changes in current. If the inductor is in a state where there is no current flowing, it will attempt to block the flow of current when the circuit is connected; If the inductor is in a state with current flowing through it, it will attempt to maintain the current constant when the circuit is disconnected. Inductors, also known as chokes, reactors, and dynamic reactors.

Inductance is the ratio of the magnetic flux of a wire to the current that produces this flux when alternating current passes through the wire. When direct current passes through the inductor, only fixed magnetic lines of force appear around it and do not change with time;

However, when AC current is passed through the coil, there will be magnetic field lines around it that change over time. According to Faraday's law of electromagnetic induction - magnetoelectricity, a changing magnetic field line generates an induced potential at both ends of the coil, which is equivalent to a "new power source". When a closed circuit is formed, this induced potential generates an induced current. According to Lenz's law, the total amount of magnetic field lines generated by induced current is determined to prevent changes in magnetic field lines. The variation of magnetic field lines comes from the variation of external alternating power supply, so objectively speaking, the inductance coil has the characteristic of preventing current changes in AC circuits. Inductive coils have characteristics similar to inertia in mechanics and are called "self induction" in electricity. Usually, sparks occur at the moment of opening or closing the knife switch, which generates a high induced potential.

In short, when the inductance coil is connected to an AC power source, the magnetic field lines inside the coil will constantly change with the alternating current, causing electromagnetic induction in the coil. The electromotive force generated by changes in the current of the coil itself is called "self induced electromotive force". From this, it can be seen that the inductance is only a parameter related to the number of coils, size, shape, and medium of the coil. It is a measure of the inertia of the inductance coil and is independent of the applied current.

Principle of substitution: 1. The inductance coil must be replaced with its original value (with equal turns and sizes). 2. The chip inductance only needs to be of the same size, and can also be replaced with a 0 ohm resistor or wire.