# What is an electric coil and what is it used for?

You have certainly heard of electric coils, and you may know some concept in relation to electric coils, but if you are curious to learn everything about electric coils, you are in the right place! In this article we will explain what electrical coils are, how electrical coils work, characteristics of coils, constitution and applications of coils. Come on guys!

## Electric coil: What is it?

Electric coils, also known as inductors or solenoids, are passive devices capable of storing electrical energy created in a magnetic field, and this field is formed by an alternating current, which passes through a conductive wire wrapped around itself, or even in around a surface that is also conductive.

What are coils and what are they for?

## Electric coil: Operation

When the electric current passes through a certain wire, a magnetic field is generated around it, and when this same wire is wound several times, several turns are formed, so that this magnetic field is enlarged, that is, the greater the number of turns of this wire, the greater the coil and the intensity of the magnetic field. It is important to note that the stronger this magnetic field, the greater the capacity of it to attract magnetic materials, such as iron and steel.

## Electric coil: Features

Inductors and capacitors have in common the ability to store energy, just like capacitors, inductors are opposed to alternating current, offering an inductive reactance, we can highlight that there is only voltage at the terminals of an inductor or a coil, if the current through it varies over time, that is, inductor is a short circuit in direct current, in addition we can relate the coils and inductors to another physical quantity, which is the inductance, represented by the letter L and measured in Henry (H).

## Electric coil: Constitution

Electric coils, in most cases, are made of a conductive material, copper. The coils have a ferromagnetic core, which increases their inductance, concentrating the lines and strength of the magnetic field that flow through the conductive turns.

There are also toroidal coils, where the toroidal core is usually made of ferrite, and has a thread shape. Thanks to this format, a path through which the magnetic field circulates is created. This type of core is used in rod shaped coils. In this case the magnetic field suffers losses when circulating from one end to the other, due to contact with air. So this nucleus was designed to make a path to this field, avoiding the number of losses.

## Electric coil: Applications

As we know, coils are also considered inductors, having several applications, among them to avoid variations of electric current, to form a transformer, construction of passive filters, constituted of resistors and / or capacitors, forming band pass filters, band rejects filter, pass filter high and low pass filter, that is, this filter allows the passage of a signal depending on high, low frequencies or in a certain frequency range.

If we stop to think a little more, the coils or inductors are very close to the electrician that you cannot imagine, such as inside circuit breakers , relays , contactors , among other electrical components.

Coils are also found in cars, as they assist in starting the engine, and it is known as an ignition coil, in addition, we can also find coils in various electronic devices.

We can mention that in most speakers a coil, electromagnet, is found. Coils are also found in electrical machines, such as transformers, induction motors and even DC motors. The video below shows exactly how a transformer works, to make it easier to understand.

We finished one more article and we hope to have helped clarify your doubts about electric coils. If you have any questions or suggestions, leave them in the comments!