Inductor Energy Calculator

1. What is Inductor Energy Calculator?

Definition: This calculator computes the energy ( $E$ ) stored in the magnetic field of an inductor when an electric current passes through it.

Purpose: It is used in electrical engineering to analyze the energy storage capacity of inductors in circuits, which is crucial for applications like power supplies, transformers, and signal processing.

2. How Does the Calculator Work?

The calculator uses the following formula:

Energy Stored: $E = \frac{1}{2} L I^{2}$

Where:

$E$ : Energy stored in the inductor (J)
$L$ : Inductance of the inductor (H)
$I$ : Current passing through the inductor (A)

Steps:

Enter the inductance ( $L$ ) and current ( $I$ ) with their units.
Convert all inputs to base units (H, A).
Calculate the energy using the formula.
Convert the result to the selected output unit (J, mJ, µJ, kJ, MJ, Wh, kWh).
Display the result: if the value is less than 0.001 in the selected unit, use scientific notation; otherwise, display with 4 decimal places.

3. Importance of Inductor Energy Calculation

Calculating the energy stored in an inductor is crucial for:

Energy Storage in Circuits: Inductors store energy in their magnetic field, which can be released when the current changes, making them essential in power supplies and switched-mode power converters.
Signal Processing: In AC circuits, inductors help filter signals by opposing rapid changes in current, which is useful in applications like radio frequency circuits.
Transformer Design: Understanding the energy storage helps in designing transformers, where magnetic energy is transferred between coils to step up or step down voltage.

4. Using the Calculator

Example 1: Calculate the energy stored in an inductor with $L = 20 µH$ and $I = 300 mA$ :

Inductance ( $L$ ): 20 µH = $20 \times 10^{- 6}$ H
Current ( $I$ ): 300 mA = $300 \times 10^{- 3} = 0.3$ A
Energy ( $E$ ): $\frac{1}{2} \cdot (20 \times 10^{- 6}) \cdot (0.3)^{2} = \frac{1}{2} \cdot (20 \times 10^{- 6}) \cdot 0.09 = 9 \times 10^{- 7} J$ , in µJ: $9 \times 10^{- 7} \times 10^{6} = 0.9 µJ$ , in kWh: $9 \times 10^{- 7} / 3600000 = 2.5 \times 10^{- 13} kWh$
Result: $E = 2.5000 \times 10^{- 13} kWh$

Example 2 (Demonstrating Larger Units): Calculate the energy stored in an inductor with $L = 2 H$ and $I = 5 A$ :

Inductance ( $L$ ): 2 H
Current ( $I$ ): 5 A
Energy ( $E$ ): $\frac{1}{2} \cdot 2 \cdot (5)^{2} = \frac{1}{2} \cdot 2 \cdot 25 = 25 J$ , in kJ: $25 \times 10^{- 3} = 0.025 kJ$ , in Wh: $25 / 3600 \approx 0.006944 Wh$
Result: $E = 0.0069 Wh$

5. Frequently Asked Questions (FAQ)

Q: What is an inductor?
A: An inductor is a passive electronic component that stores energy in a magnetic field when an electric current flows through it. It typically consists of a coil of wire, often wrapped around a core material.

Q: Why does the energy depend on the square of the current?
A: The energy stored in an inductor is proportional to $I^{2}$ because the magnetic field strength is proportional to the current, and the energy is related to the square of the magnetic field strength.

Q: How can the energy storage in an inductor be increased?
A: To increase the energy stored, you can either increase the inductance ( $L$ ) by using a core material with high permeability (e.g., ferromagnetic cores) or increase the current ( $I$ ) passing through the inductor.