In this article, we will discuss the iron core inductor, its construction, formula of inductance, working, advantages, and applications. But before that let us have a look into the basics of inductors.
What is an Inductor and its Types?
An inductor is an electric circuit component that stores electrical energy in the form of a magnetic field. A simple inductor is formed by twisting a wire of finite length into a coil. Thus, an inductor is made up of a conducting wire.
The property of the inductor by which it stores electrical energy in the form of a magnetic field is referred to as the inductance of the inductor. The inductance is usually denoted by the symbol L and is measured in Henry (H).
The circuit symbol of a typical inductor is shown in Figure 1. An inductor has a coil-form structure and it has a finite number of turns.
Based on the core used at the center of the inductor, there are several types of inductors like air core inductors, iron core inductors, etc. In this article, we shall confine our attention to the iron core inductor only.
What is an Iron Core Inductor?
An iron core inductor is a type of inductor that uses iron or ferromagnetic material as the core at the center of its coil. The use of an iron core in an inductor allows for a higher inductance value, as the iron core provides a greater magnetic field than other materials like air or a ferrite core. Iron core inductors are commonly used in power supply circuits, filters, and transformers. They may also be used in applications where an inductor having a high inductance value is required, for example in radio frequency (RF) circuits.
The iron core of the inductor has the property of strengthening the magnetic field. By introducing an iron core in the inductor coil, we can increase the inductance value of the inductor. The circuit symbol of the iron core inductor is shown in Figure 2.
Construction of Iron Core Inductor
An iron core inductor is constructed by winding a coil of conductor wire around an iron or ferromagnetic core as shown in figure 3.
The core material, i.e. iron is chosen for the high permeability that allows it to support a stronger magnetic field as compared to other materials. The coil is made from a conductor wire that has low electrical resistance, such as copper or aluminum, and is wound around the iron core in a specific pattern to increase the inductance of the inductor. The inductance of the iron core inductor is greatly affected by the physical parameters of the inductor like the number of turns in the coil, the size, and shape of the core, and the type of wire used.
Once the coil is wound around the iron core, it is then enclosed in a protective housing to protect it from mechanical damage and prevent interference from affecting its operation and performance.
Working of Iron Core Inductor
The working of an iron core inductor is similar to an ordinary inductor, i.e. it stores electrical energy in the magnetic field. But, the iron core of the inductor increases its inductance by providing a high-permeability material for the magnetic field to pass through. The coil of wire that makes up the inductor is wound around the iron core, and the magnetic field generated by the current flowing through the coil is concentrated in the core. Therefore, the iron core increases the strength of the magnetic field, which in turn increases the inductance of the inductor.
Inductance Formula for Iron Core Inductor
Let,
Then, the inductance of the iron core inductor can be determined using the following formula,
This inductance is measured in Henry (H).
Advantages of Iron Core Inductors
Iron core inductors have many advantages, some of which are listed below:
- Low Losses: Iron core inductors have low losses due to low resistance and hysteresis.
- Stable Inductance: Iron core inductors have a relatively stable inductance over a wide range of temperatures and frequencies.
- High Permeability: Iron has a high permeability, which means it can support a strong magnetic field.
- Low Cost: Iron is a relatively inexpensive material, making iron core inductors less expensive to manufacture.
- High Saturation Point: Iron has a high saturation point, meaning it can support a strong magnetic field without becoming saturated. This allows iron core inductors to handle high currents without saturating.
Disadvantages of Iron Core Inductors
There are also some disadvantages of iron core inductors:
- Size: Iron core inductors tend to be larger and heavier than inductors with other types of cores.
- Non-Linearity: Iron core inductors can exhibit non-linear behavior at high levels of magnetization, which can cause their inductance to change with the level of current flowing through them.
- Susceptibility to Corrosion: Iron is susceptible to corrosion, which can affect the performance of iron core inductors.
- Temperature Sensitivity: Iron core inductors can be sensitive to temperature changes, which can cause their inductance to change.
- AC Resistance: Iron core inductors have a higher AC resistance than inductors with other types of cores, which can cause losses at high frequencies.
Applications of Iron Core Inductors
The following are some applications of iron core inductors:
- Iron core inductors are used in power converters to store energy in their magnetic field and reduce voltage fluctuations.
- Iron core inductors are used in motor control circuits to reduce the current spikes and protect motors from damage.
- Iron core inductors are used in electric power transmission systems to improve the current flow and protect equipment from voltage fluctuations.
- Iron core inductors are used in RF (Radio Frequency) circuits like antennas, amplifiers, and oscillators.
- Iron core inductors are used in filter circuits to block or pass certain frequencies for noise reduction and signal separation.
- Iron core inductors are used in different kinds of electronic devices such as radios, televisions, and computers.