## Inductor

### What is an Inductor?

An inductor is an electrical component that stores energy in a magnetic field when current flows through it. It is also known as a coil or reactor. An inductor is made up of a conducting wire that is wound into a coil or helix shape, and the energy is stored in the magnetic field that surrounds the coil. Inductors are passive components and are commonly used in electronic circuits to filter, smooth, or store energy. They are also used in transformers, motors, generators, and other electrical devices. The amount of energy that an inductor can store is proportional to its inductance, which is measured in henries. Inductors are similar to capacitors in that they can store energy, but while capacitors store energy in an electric field, inductors store energy in a magnetic field.

#### Symbol of Inductor

The electrical symbol of an inductor is a coiled wire or series of loops, usually with two terminals, as shown below:

This symbol is used in circuit diagrams to represent an inductor. The inductor's terminals are represented by the wires on either side of the symbol, and the coiled wire represents the inductor itself. The symbol can be drawn with more or fewer loops depending on the specific inductor and its inductance value.

### Inductance

Inductance is a property of an electrical component called an inductor, which is the ability of the inductor to store energy in the form of a magnetic field when a current flows through it. Inductance is represented by the symbol "L" and is measured in henries (H). The inductance of an inductor depends on the number of turns in the coil, the size of the coil, and the material that the coil is made of.

The amount of inductance in an inductor is determined by the rate at which the magnetic field changes in response to the current flowing through it. The greater the rate of change, the greater the induced electromotive force (EMF) in the inductor. This relationship is known as Faraday's law of induction.

Inductors are commonly used in electronic circuits to filter, smooth, or store energy. The inductance of an inductor can be increased by increasing the number of turns in the coil, using a larger coil, or using a material with a higher magnetic permeability.

### Formula

Here is the inductor formula in LaTeX format, which can be used in HTML:

The formula for the inductance of an inductor is:

$$L = \frac{\phi}{I}$$

where:

• L is the inductance of the inductor, measured in henries (H)
• $\phi$ (phi) is the magnetic flux through the inductor, measured in webers (Wb)
• I is the current flowing through the inductor, measured in amperes (A)

Another formula that relates inductance, number of turns, and magnetic flux density is:

$$L = \frac{N^2}{R} \cdot \mu \cdot A$$

where:

• L is the inductance of the inductor, measured in henries (H)
• N is the number of turns of wire in the inductor
• R is the reluctance of the magnetic circuit, measured in ampere-turns per weber (AT/Wb)
• $\mu$ (mu) is the permeability of the core material, measured in henries per meter (H/m)
• A is the cross-sectional area of the core, measured in square meters (m²)

#### Serial and Parallel inductors

In a series combination of inductors, the inductances are added together to obtain the total inductance. That is, if L1, L2, and L3 are the inductances of three inductors connected in series, then the total inductance, LTotal, is:

LTotal = L1 + L2 + L3

The current flowing through each inductor in a series combination is the same, but the total voltage across the combination is the sum of the voltages across each individual inductor.

In a parallel combination of inductors, the total inductance is less than the value of the smallest inductor in the combination. The total inductance, LTotal, is given by the formula:

1/LTotal = 1/L1 + 1/L2 + 1/L3

The voltage across each inductor in a parallel combination is the same, but the total current flowing through the combination is the sum of the currents flowing through each individual inductor.

#### Types of Inductors

There are several types of inductors used in electronic circuits, including:

1. Air-core inductors: These inductors have a core made of air or a non-magnetic material. They are used when a high-quality factor (Q) is required, and when magnetic interference must be minimized.

2. Iron-core inductors: These inductors have a core made of ferromagnetic material, such as iron, and are commonly used in power supply and audio applications.

3. Toroidal inductors: These inductors have a core shaped like a torus (a doughnut shape) and are used when a high inductance is required in a small package.

4. Multilayer ceramic inductors: These inductors are made by layering ceramic material and conductive material. They are used in high-frequency circuits and are known for their stability and reliability.

5. SMD inductors: These inductors are small and compact, designed for use in surface-mount technology (SMT) applications.

6. RF inductors: These inductors are designed for use in radio frequency (RF) circuits and have a high Q factor and low resistance.

7. Coupled inductors: These inductors consist of two or more inductors that are magnetically coupled together. They are used in transformer and resonant circuits.