Inductive Component
The inductive component is an energy storage component. The original model of the inductive component is a wire wound into a cylindrical coil. When the current i is passed through the coil, a magnetic flux Φ is generated in the coil and energy is stored. A parameter that characterizes the inductance of an inductive component (referred to as an inductor), the ability to store a magnetic field, also called an inductor, is represented by L, which is numerically equal to the flux linkage produced by a unit current. Inductive components refer to inductors (inductors) and various transformers.

The “inductive component” is a basic circuit component other than the resistive element R and the capacitive element C in the circuit model in the “circuit analysis” discipline. In a linear circuit, the inductive component is represented by an inductance L. The "volt-ampere relationship" of a component is a necessary constraint in addition to Kirchhoff's law in linear circuit analysis. The volt-ampere relationship of the inductive component is v=L(di/dt), that is, the voltage across the inductive component is different from the resistive component R except for the inductance L, which does not depend on the current i itself but on The rate of change of current versus time (di/dt). The faster the current changes, the greater the voltage across the inductor, and vice versa. Accordingly, in the "steady state" case, when the current is DC, the voltage across the inductor is zero; when the current is sinusoidal, the voltage across the inductor is also a sine wave, but the phase is advanced (π/2) When the current is a periodic isosceles triangle wave, the voltage is a rectangular wave, and so on. In general, the voltage waveform across the inductor changes faster than the current and contains more low frequency components.

In layman's terms, the number of magnetic lines passing through a closed conductor loop is called the magnetic flux. Due to the magnetic flux variation that is formed inside the magnetic field through the closed current-carrying conductor (in many cases the coil), according to Faraday's law of electromagnetic induction, the closed conductor will generate an electromotive force to "react" this change, ie electromagnetic induction. The electromagnetic induction of the inductive component is divided into self-induction and mutual induction. The electromagnetic induction phenomenon caused by the change of magnetic flux in the magnetic field is called “self-induction” phenomenon; the electromagnetic induction phenomenon caused by the change of magnetic flux in the external magnetic field is called "mutual induction" phenomenon.

For example, when a current passes through a 1 Henry inductive component at a rate of change of 1 amp/sec, it induces an induced electromotive force of 1 volt. When the number of turns of the wire wound conductor increases, the inductance of the conductor also becomes larger, not only the number of turns, but also the area of ​​each turn (loop), and the winding material affects the inductance. In addition, winding the conductor with a highly permeable material also increases the magnetic flux. More information in