Inductors, Functions and Types

By | September 5, 2021

Inductors are electronic components that are widely used, especially in signal and frequency processing circuits, whose currents and voltages vary.

An inductor has an inductance, but no resistance/capacitance and does not dissipate the power/field of an inductor that can produce an electric voltage directly proportional to the instantaneous change in the electric current flowing through it.  Inductors belong to the group of passive components.

An inductor is an electronic component consisting of an arrangement of wire turns that form a coil. Inductor has a unit that is henry. However, the henry unit is too large, so a smaller unit is used, namely microhenry (mH). Where 1 henry is equal to 1000 electenry(mH).

The inductor is more familiarly called the spool or coil, some call the inductor a choke or reactor.

How Inductors Work

The way inductors work is based on Faraday’s law. Faraday’s law is a law that explains how an electric current can cause electromagnetism. On the other hand, Faraday’s law also explains how a magnetic field can turn into an electric current. Faraday’s law was proposed by an English scientist named Michael Faraday in 1831.

An inductor if given an electric current then around the inductor will arise a magnetic field. The magnetic field will be stored temporarily in the coil, until there is a change in the direction of the electric current.

When in an inductor there is a change in the direction of the current, the magnetic field stored in the inductor will transform into an electric voltage. The greater the magnetic field produced by an inductor, the greater the potential voltage generated.

An inductor can consist of a single winding or several turns in one core. If the inductor is just a single coil, then if the inductor is energized then each winding of the coil will induce the other coil, causing a magnetic field. This phenomenon is termed self induction or self induction.

The inductance value of an inductor is influenced by 4 factors :

• The number of turns is directly proportional to the inductance.
• Diameter of the winding wire, directly proportional to its inductance
• Core Permeability, namely the core material used such as ferrite, iron or air
• The length of the inductor winding, the shorter the higher the inductance.

Inductor Symbol

As is known, the unit of inductor is Henry and its symbol is L (Lenz). Meanwhile the inductor symbol is as shown below:
Inductor symbol


Types of Inductors

Inductors consist of several types, the differences in the types of inductors are based on the shape and material used to make the inductor core.

1. Iron Core Inductor

Iron Core Inductor is a type of inductor that has a core made of iron. The amount of iron core used in an inductor varies depending on needs.

2. Air Core Inductor

Air Core Inductor is a type of inductor that uses an air core. This type of inductor is also known as a coreless inductor.

3. Ferrite Core Inductor

Ferrite Core Inductor is a type of inductor that uses a ferrite core. This one inductor is often found in quite complicated electronic circuits.

4. Torroidal Core Inductor

Torroidal Core Inductor is a type of inductor that has a circular or O shape like a ring or donut shape. This type of inductor is usually found in television circuits.

5. Laminated Core Inductor

Laminated Core Induction is a type of inductor with a core consisting of several types of metal. Several types of metal are connected in parallel with insulation made of insulation.

6. Variable Inductor

Variable Inductor is a type of inductor whose inductance value can be adjusted as desired. Usually this one inductor uses ferrite material.

types of inductor


Inductor Function

Inductors have many functions in everyday life in the field of electronics and electrical equipment.
The main function of an inductor in a circuit is to resist fluctuations in the current passing through it.
The following are some of the functions of the inductor including:

1. Stores electric current in the form of a magnetic field.
2. Withstand alternating current (AC).
3. Forward or pass direct current (DC).
4. As a filter (filter) as a tuning (tuning).
5. There are coils or coils that have an air core, an iron core, and a ferrite core.
6. The place where the magnetic force occurs.
7. Together with the capacitor the inductor can function as a resonator circuit that can resonate at high frequencies.
8. Two or more inductors are magnetically coupled to form a transformer.
9. Multiply the applied voltage.
10. As a vibration generator.

Inductors are usually also applied to electronic devices such as electric motors, relays, speakers, microphones, transformers, and many others.