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.
