Information about Electronics: Inductor

Information about Electronics;

In this blog I will be describe Inductor types and features.

Inductor;

An inductor, 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. An inductor typically consists of an insulated wire wound into a coil around a core.

Inductor types based on core;

There are different types of inductors. Depending on their material type they are basically categorized as follows,

Air Core Inductor;

Ceramic core inductors are referred as “Air core inductors”. Ceramic is the most commonly used material for inductor cores. Ceramic has very low thermal co-efficient of expansion, so even for a range of operating temperatures the stability of the inductor’s inductance is high. Since ceramic has no magnetic properties, there is no increase in the permeability value due to the core material.

Iron Core Inductor;

In the areas where low space inductors are in need then these iron core inductors are best option. These inductors have high power and high inductance value but limited in high frequency capacity. These are applicable in audio equipment’s. When compared with other core indictors these have very limited applications.

Ferrite Core Inductor;

Ferrites are mainly two types they are soft ferrites and hard ferrites. These are classified according to the magnetic coercively. Ferrite is also referred as ferromagnetic material. They exhibit magnetic properties. They consist of mixed metal oxide of iron and other elements to form crystalline structures . The general composition of ferrites is XFe2O4. Where X represents transition materials. Mostly easily magnetized material combinations are used such as manganese and zinc (MnZn), nickel and zinc (niZn).

Soft Ferrite;

These materials will have the ability to reverse their polarity of their magnetization without any particular amount of energy needed to reverse the magnetic polarity.

Hard Ferrite;

These are also called as permanent magnets. These will keep the polarity of the magnetization even after removing the magnetic field.

Ferrite core inductor will help to improve the performance of the inductor by increasing the permeability of the coil which leads to increase the value of the inductance. The level of the permeability of the ferrite core used within the inductors will depend on the ferrite material. This permeability level ranges from 20 to 15,000 according to the material of ferrite.

Iron Powder Inductor;

These are formed from very fine particles with insulated particles of highly pure iron powder. This type of inductor contains nearly 100% iron only. It gives us a solid looking core when this iron

power is compressed under very high pressure and mixed with a binder such as epoxy or phenolic. By this action iron powder forms like a magnetic solid structure which consists of distributed air gap.

Laminated Core Inductor;

These core materials are formed by arranging many number of laminations on top of each other. These laminations may be made up of different materials and with different thicknesses. So this construction has more flexibility. These laminations are made up of steel with insulating material between them.

These are arranged parallel to the field to avoid eddy current losses between the laminations. These are used in low frequency detectors. They have high power levels so, they are mostly used at power filtering devices for excitation frequencies above several KHz.

Bobbin based inductor;

These are wounded on cylindrical bobbin so these are named as bobbin based inductors. These are mainly used for mounting on printed circuit boards.

It consist of two types of leads they are axial lead and radial lead. Axial lead means lead exits from both sides of the core for horizontal mounting on PC board. Radial lead means lead exits from both sides of the core for vertical mounting on PC board.

Multi-layer Ceramic Inductors;

The name itself indicates that it consist of multi layers. Simply by adding additional layers of coiled wire that is wound around the central core to the inductor gives multi-layer inductor. Generally for more number of turns in a wire, the inductance is also more.

Film Inductor;

These uses a film of conductor on base material. Thus according to the requirement this film is shaped for conductor application. Film inductors in thin size are suitable for DC to DC converters that serve as power supplies in smart phones and mobile devices.

Variable Inductor;

It is formed by moving the magnetic core in and outside of the inductor windings. By this magnetic core we can adjust the inductance value. When we consider a ferrite core inductor, by moving its core inside and outside on which the coil is wounded, variable ferrite core inductor can be formed.

Coupled Inductors

The two conductors connected by electromagnetic induction are generally referred as coupled inductors. We already seen that whenever the AC current is flowing in one inductor produces voltage in second inductor gives us mutual inductance phenomenon.