1. What is a Toroid Inductor Design Calculator?

Definition: This calculator computes the inductance of a toroidal (doughnut-shaped) inductor based on its physical characteristics.

Purpose: It helps electrical engineers and electronics enthusiasts design toroidal inductors for circuits, power supplies, and RF applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( L \) — Inductance in henrys (H)
• \( \mu \) — Permeability of the core material (H/m)
• \( N \) — Number of wire turns
• \( A \) — Cross-sectional area of the core (m²)
• \( r \) — Mean radius of the toroid (m)

Explanation: The inductance increases with more turns, larger core area, and higher permeability materials, but decreases with larger toroid radius.

3. Importance of Toroid Inductor Design

Details: Toroidal inductors offer superior magnetic field containment, higher inductance values, and reduced electromagnetic interference compared to other inductor shapes.

4. Using the Calculator

Tips:

• μ: Default is permeability of free space (1.256637×10⁻⁶ H/m)
• N: Typically between 10-1000 turns depending on application
• A: Cross-section area (π × (core radius)²)
• r: Distance from center to middle of the core

All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical permeability value for ferrite cores?
A: Ferrite cores typically have μ between 1,000-15,000 times μ₀ (free space permeability).

Q2: How does core material affect inductance?
A: Higher permeability materials yield higher inductance for the same physical dimensions.

Q3: Why use toroidal instead of solenoid inductors?
A: Toroids have lower electromagnetic interference and higher inductance per volume.

Q4: How accurate is this calculation?
A: It provides theoretical values; actual inductance may vary due to winding tightness and core imperfections.

Q5: What units should I use?
A: All inputs must be in meters (m) and henrys per meter (H/m) for consistent results.