Ruigu Electronic

Understanding Inductors: Function and Applications

2025-11-29

An inductor is an electronic component that can convert electrical energy into magnetic energy and store it. It is widely used in electronic circuits and is one of the key components for realizing functions such as oscillation, tuning, coupling, filtering, delay, and deflection.

Here is a detailed introduction:

Definition and Basic Structure

An inductor is an electronic component made by winding one or more turns of wire to generate a certain self – inductance. It is usually composed of a skeleton, a winding, a magnetic core or iron core, a shielding cover, packaging materials, etc. The skeleton is the support for winding the coil, which is usually made of plastic, bakelite, ceramic, etc. The winding is the basic part of the inductor, which can be divided into single – layer and multi – layer types. The magnetic core or iron core is used to increase the inductance, and common materials include nickel – zinc ferrite, manganese – zinc ferrite, silicon steel sheet, etc.

Working Principle

The working principle of an inductor is based on the electromagnetic induction phenomenon. When current passes through the coil of the inductor, a magnetic field will be generated. When the current changes, the magnetic field also changes accordingly, thereby generating an induced electromotive force in the coil. This phenomenon is called self – induction. The induced electromotive force will hinder the change of the current, which is the characteristic of the inductor “blocking alternating current and passing direct current”.

Main Parameters

Inductance: It is a parameter that measures the ability of an inductor to store magnetic energy, represented by the symbol “L”, and the unit is henry (H).
Quality Factor (Q Value): It is an index to measure the energy loss of an inductor at a specific frequency. The higher the Q value, the lower the energy loss.
Self – Resonant Frequency (SRF): It is the frequency at which the inductance and distributed capacitance of the inductor resonate in series, which limits the effective operating frequency range of the inductor.
Rated Current: It is the maximum current that the inductor can continuously carry without causing significant temperature rise.

Types

According to the Winding Method: It can be divided into single – layer coils, multi – layer coils, honeycomb coils, etc.
According to the Magnetic Conductive Properties: It can be divided into air – core coils, ferrite coils, iron – core coils, copper – core coils, etc.
According to the Working Properties: It can be divided into antenna coils, oscillation coils, choke coils, filter coils, notch coils, deflection coils, etc.