What is Inductor, types, function and uses

 Inductors

Inductor is  also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. Inductors much like conductors and resistors are simple components that are used in electronic devices to carry out specific functions. Normally, inductors are coil-like structures that are found in electronic circuits. The coil is an insulated wire that is looped around the central core.

Inductors are mostly used to decrease or control the electric spikes by storing energy temporarily in an electromagnetic field and then releasing it back into the circuit.

What is Inductor?

An inductor is a passive component that is used in most power electronic circuits to store energy in the form of magnetic energy when electricity is applied to it. One of the key properties of an inductor is that it impedes or opposes any change in the amount of current flowing through it. Whenever the current across inductor changes it either acquires charge or loses the charge in order to equalize the current passing through it. The inductor is also called as choke, reactor or just coil.

Different Types of Inductors

• Iron Core Inductor
• Air Core Inductor
• Iron Powder Inductor
• Ferrite Core Inductor which is divided into two type 
• Soft Ferrite
• Hard Ferrite

Iron Core Inductor

As the name suggests the core of this type of inductor is made of iron. These inductors are low space inductors that have high power and high inductance value. However, they are limited in high-frequency capacity. These inductors are used in audio equipment.

Air Core Inductor

These inductors are used when the amount of inductance required is low. Since there is no core, it does not have a core loss. But the number of turns the inductor must have is more for this type when compared to the inductors with the core. This results in a high-Quality factor. Usually, ceramic inductors are often referred to as air-core inductors.

Iron Powder Inductor

In this type of inductor core is Iron Oxide. They are formed by very fine and insulating particles of pure iron powder. High magnetic flux can be stored in it due to the air gap. Permeability of the core of this type of inductor is very less. They are usually below 100. They are mainly used in switching power supplies.

Ferrite Core Inductor

In this type of Inductor, ferrite materials are used as core. The general composition of ferrites is XFe2O4  Where X represents transition material. Ferrites can be classified into two types. Soft ferrites and hard ferrites.

Soft Ferrite: Materials that have the ability to reverse their polarity without any external energy.

Hard Ferrite: These are permanent magnets. That is their polarity will not change even when the magnetic field is removed.

Functions of an Inductor

• Control signals.
• Store energy.

Controlling Signals

Coils in an inductor can be used to store energy. The function of the inductor depends upon the frequency of the current passing through it. That is for higher frequency signals will be passed less easily and vice versa. This function tells that it blocks AC Current and passes DC Current. Hence, it can be used to block AC signals.

Storing Energy

Inductor stores energy in the form of magnetic energy. Coils can store electrical energy in a form of magnetic energy using the property that an electric current flowing through a coil produces a magnetic field, which in turn produces an electric current. In other words, coils offer a means of storing energy on the basis of inductivity

Uses of inductor

• Tuning circuits
• Sensors
• Store energy in a device
• Induction motors
• Transformers
• Filters
• Chokes
• Ferrite beads
• Inductors used as relays

Tuning circuits

With the help of inductors, the tuning circuits can select the desired frequency. The capacitors type along with the inductor are used in various electronic devices such as radio tuning circuits, a television in order to modify the frequency and help to select within multiple channels of frequency.

Sensors

The inductive proximity sensors are very reliable in operation and is a contactless sensor. Inductance is the main principle behind it in which the magnetic field in the coil will oppose the flow of electric current. The proximity sensors mechanism is used in traffic lights to detect traffic density.

Store energy in a device

Inductors can store energy for a small period of time because the energy which is being stored as a magnetic field will be gone when the power supply is removed. Uses of inductors can be seen in computer circuits where power supplies can be switched.

Induction motors

In induction motors, the shaft in the motor will rotate due to the presence of the magnetic field produced due to alternating current. The speed of the motor can be fixed according to the frequency of the supply of power from the source. The use of inductors into the motor’s speed can be controlled.

Transformers

A combination of multiple inductors with a shared magnetic field can be designed into a transformer. One of the major uses of transformer can be seen in power transmission systems. These are used in decreasing or increasing the power transmission as step down or step-up transformers.

Filters

Inductors when combined with capacitors will be used as filters. The input signal’s frequency while entering the circuit is limited by the use of these filters. With the increase in the frequency of supply, the inductor’s impedance increases.

Chokes

As we are aware that when AC current flows through inductors, it will create a current flow in the opposite direction. This results in the inductor choking the AC current flow and passing the DC current. This mechanism is used in the power source where the AC supply is converted into DC.

Ferrite beads

We have seen ferrite beads used in computer parts and in charging cables of mobile. Inductors used in ferrite beads helps in reducing the frequency of radio interface which the cable creates.

Relays

Relay behaves as an electrical switch. With the use of an inductor coil in the switch, there is a magnetic field produced wherever the switch comes in contact with the flow of AC current.