Inductors are components that can convert electrical energy into magnetic energy and store it. The structure of inductor is similar to that of transformer, but there is only one winding. The inductor has a certain inductance, which only blocks the change of current.
If the inductor is in the state of no current passing, it will try to prevent the current from flowing through it when the circuit is connected; If the inductor is in a state of current flow, it will try to maintain the current when the circuit is disconnected. Inductor is also called choke, reactor and dynamic reactor.
Inductors are generally composed of skeleton, winding (winding), shielding cover, packaging materials, magnetic core or iron core, etc. magnetic core and winding are the soul of inductance.
There are many kinds of inductors with different shapes. The more common ones are: single-layer flat wound hollow core inductors, inter wound hollow core inductors, bodiless hollow core inductors, multi-layer hollow core inductors, honeycomb inductors, inductors with magnetic cores, magnetic can inductors, high-frequency choke coils, low-frequency choke coils, fixed inductors, etc.
When there is current flowing through the coil, a magnetic field will be generated around the coil. When the current in the coil changes, the magnetic field around it also changes correspondingly. The changed magnetic field can make the coil generate induced electromotive force (induced electromotive force) (electromotive force is used to represent the terminal voltage of the ideal power supply of the active element), which is called self inductor.
Electronic components, which are wound with wires and have a certain number of turns and can produce a certain amount of self inductance or mutual inductance, are often called inductive coils. In order to increase the inductance value, improve the quality factor and reduce the volume, iron cores or cores made of ferromagnetic materials are often added. The basic parameters of an inductor include inductance, quality factor, inherent capacitance, stability, passing current, frequency of use, etc. An inductor composed of a single coil is called a self inductor, and its self inductance is also called a self inductance coefficient.
When two inductance coils are close to each other, the magnetic field change of one inductance coil will affect the other inductance coil, which is mutual inductance. The size of mutual inductance depends on the degree of coupling between the self inductance of the inductance coil and the two inductance coils. The element made by using this principle is called mutual inductor.