🔌 Inductor Calculator

Calculate inductance, energy, and reactance

📏 Input Parameters

Inductance (mH)

Current (A)

Frequency (Hz)

📊 Results

Energy (E)

5.0 mJ

Reactance (XL)

62.8 Ω

📚 Understanding Inductors

What is an Inductor?

An inductor is a passive electronic component that stores energy in a magnetic field when current flows through it. It's essentially a coil of wire, often wound around a magnetic core.

Formulas

Energy: E = ½ × L × I²

Inductive Reactance: XL = 2π × f × L

E: Energy stored (Joules)
L: Inductance (Henries)
I: Current through inductor (Amperes)
XL: Inductive reactance (Ohms)
f: Frequency (Hertz)

Common Applications

Power Supplies: Switching regulators, DC-DC converters
Filters: Low-pass, high-pass, and band-pass filters
RF Circuits: Tuning circuits, impedance matching
Energy Storage: Flyback converters, boost converters
EMI Suppression: Reducing electromagnetic interference

Key Characteristics

Opposes changes in current (like capacitors oppose voltage changes)
Reactance increases with frequency
Acts as short circuit at DC, open circuit at high frequencies
Can generate high voltage spikes when current is interrupted

Frequently Asked Questions

What is inductive reactance?

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Inductive reactance (XL) is the opposition an inductor presents to AC current. It increases with frequency, meaning inductors block high frequencies while passing low frequencies and DC.

Why do inductors generate voltage spikes?

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When current through an inductor is suddenly interrupted, the collapsing magnetic field induces a high voltage spike (V = L × di/dt). This is why flyback diodes are used to protect circuits.

How do I choose an inductor for a power supply?

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Consider inductance value, current rating, DC resistance, and saturation current. For switching regulators, use the formula L = (Vin - Vout) × Ton / ΔI, where ΔI is the ripple current.