Electric current flowing through an inductor

An inductor is a passive electronic component that stores energy in the form of a magnetic field when an electric current flows through it. Inductors are typically made of a coil of conducting wire, often wound around a magnetic core made from iron or ferrite. The ability of an inductor to store energy is quantified by its inductance, measured in henries (H). The inductance depends on factors such as the number of turns in the coil, the coil's radius, and the type of material used for the core.

Inductors are commonly used in electronic circuits for various purposes, including filtering, energy storage, and signal processing. In power supply circuits, inductors are often used in conjunction with capacitors to filter out alternating current (AC) components from a direct current (DC) signal. In radio-frequency circuits, inductors are used in oscillators and tuners to select specific frequencies. Inductors are also key components in transformers, which are used to step up or step down AC voltages.

One of the fundamental properties of an inductor is its opposition to changes in current, described by Faraday's law of electromagnetic induction. When the current through an inductor changes, it induces a voltage across the inductor that opposes the change in current. This property is utilized in applications like energy storage in switching power supplies and in the smoothing of current in electrical motors.

However, inductors are not ideal components; they come with parasitic properties like resistance and capacitance, which can affect their performance. The resistance of the wire used in the coil introduces energy losses, known as copper losses. Inductors can also have a phenomenon known as "core loss" due to the hysteresis and eddy currents in the magnetic material. These factors need to be considered in circuit design to minimize inefficiencies.

Inductors can come in various shapes and sizes, from tiny surface-mount components for high-frequency applications to large, heavy-duty inductors used in power distribution systems. The choice of inductor depends on the specific requirements of the application, such as the operating frequency, current rating, and inductance value.

In summary, an inductor is a passive electronic component that stores energy in a magnetic field when a current flows through it. It is used in a wide range of applications, from filtering and energy storage to signal processing and frequency selection. The performance of an inductor is characterized by its inductance, and it is influenced by factors like coil geometry and core material. Inductors are fundamental components in both simple and complex electronic circuits.