All You Need To Know About Inductors

Inductors are passive two-terminal electrical components that resist any changes in electric current passing through them. Majority of inductors are made of copper, and they comprise of a conductor in the form of a wire wound into a coil. Energy is stored in the coil as magnetic field as long as current flows through it. When current changes, the magnetic field induces a voltage in the conductor that opposes the change. The capacity/inductance of an inductor depends upon the material used, the number of coils and the diameter of the inductor. This inductance is conveyed in Henries unit, which is the outcome of the magnetic flux created around the conductor by the flow of current.

Structure of inductors

Inductors have a very simple and easy-to-understand structure. They have a coil of conducting material of insulated copper wire wrapped around a core made of plastic or ferromagnetic magnetic material. These materials are used because of their high permeability, meaning the property of supporting electromagnetism. This property of permeability increases the inductance of any core and helps in getting maximum resistance.

Applications of inductors

·        Inductors are used in analog circuits and signal processing. Large inductors are used in power supplies which remove residual hums and other fluctuations from the direct current output with the help of filter capacitors. They are also used as energy storage devices in SMPS to produce DC current, where the inductor supplies energy to the circuit for current flow during the “off” mode.

·        Tuned circuits, which are formed when inductors are connected to capacitors, are used in radio frequency equipment like radio transmitters and receivers. They are used to select a single frequency from a composite signal, and to generate sinusoidal signals in electronic oscillators.

·        Transformers, formed with two or more inductors in proximity with coupled magnetic flux, are used in every electric utility power grid.

Types of inductors

There are a variety of inductors available, out of which the below three are the most commonly used. Miracle Electronics is the Leading Inductor Coil Manufacturer in India, where you can get a variety of inductors that have no air gap, produce no noise, have a low electromagnetic radiation and are built with a very safe design with superior quality wiring and high durability index.

·        Ferromagnetic/Iron core inductors – These inductors have iron or ferrite in their core to increase inductance because iron is more permeable than other metals. Transformers and heavy pieces of machinery use these types of inductors because they require high inductance and low resistance. However, the magnetic properties of the core may cause side effects, which may alter the behavior of the inductor. Thus, either special construction or core replacement from time to time is required.

·        Air core inductor – Unlike ferromagnetic conductors, air core conductors do not have any metal in their core. Instead, they have materials like plastic, ceramic or just air in the space of winding. Inductance in such inductors is lesser and they can be used for higher frequencies as they have no limitations of core loss. However, if there are many mechanical vibrations in the system, the desired inductance of air core inductors will be different.

·        Laminated core inductor – Inductors that require low inductance are made from laminated core materials, which are a number of laminated sheets that are covered with insulation material. These inductors are used to decrease eddy currents between the sheets so that energy loss is greatly reduced.

SUMMARY

Inductors are two-terminal electrical components with a coil of wire wrapped around a core that resist changes in electric current passing through them. Inductors store energy in the coil as magnetic field, which induces a voltage to oppose any change in current felt.