An inductor, also known as a reactor or coil, is a passive electronic component that stores energy in a magnetic field when electric current flows through it.
Inductors are typically used in electronic circuits to oppose changes in current, and they are often used in combination with capacitors to form resonant circuits. Inductors can also be used to filter unwanted signals in a circuit or to provide electromagnetic shielding. They are commonly made of a coil of wire, such as copper, wrapped around a core made of a magnetic material, such as iron.
Features of Inductor
- Inductive reactance: The opposition to current flow in an inductor is known as inductive reactance. It is measured in ohms and increases with the increasing frequency of the current.
- Self-inductance: The property of an inductor to oppose changes in current flowing through it is known as self-inductance.
- Mutual inductance: When two or more inductors are placed near each other, the magnetic field of one can induce an electromotive force (EMF) in the other, this phenomenon is known as mutual inductance.
- Energy storage: An inductor can store energy in its magnetic field when current flows through it. When the current is interrupted, the stored energy can be released.
- Inductor value: Inductors can be designed and manufactured with different values of inductance, typically measured in microhenries (uH) or millihenries (mH).
Symbol of Inductor
Types of Inductor
- Air-core inductors
- Iron-core inductors
- Toroidal inductors
- Ferrite-core inductors
- Powdered-iron core inductors
- Multi-winding Inductors
- Variable Inductors
Working of Inductor
An inductor works by using the principle of electromagnetic induction, which states that a changing current in one coil of wire will induce a voltage in a nearby coil of wire. In an inductor, a coil of wire is wrapped around a core, which can be made of a magnetic material such as iron or air.
When an alternating current (AC) flows through the inductor’s coil, it creates a magnetic field around the coil. The strength of this magnetic field is directly proportional to the amount of current flowing through the coil. As the current changes, the magnetic field also changes, and this changing magnetic field induces a voltage across the coil.
When a direct current (DC) flows through the coil, the magnetic field around the coil becomes steady, and no voltage is induced in the coil. This is the reason that an inductor is not effective in blocking DC signals, but it is effective in blocking AC signals.
Application of Inductor
- Filtering
- Power supplies
- Transformers
- Inductive Sensing
- RF Circuits
- Switching power supplies
- Motor Control