Toroid Calc | Magnetic Suite

Toroid Designer

Magnetic Core Analysis

Toggle AL for most manufacturers (Amidon, TDK)

55.0 µH (MICROHENRIES)
Rule of Thumb: Inductance increases with the square of the turns. Doubling the turns gives 4x the inductance.

A toroid's inductance depends on the core material's permeability, the physical dimensions of the ring, and the square of the number of turns.

Core Formulas:

  1. Core Saturation: Every core has a limit to how much magnetic flux it can handle (Bmax​). If your current is too high, the core "saturates," and your inductor essentially becomes a piece of wire (inductance collapses), which can cause circuit failure.
  2. Iron Powder vs. Ferrite:
    • Iron Powder (e.g., Yellow/White cores): Lower permeability, but handles high DC currents without saturating. Great for power chokes.
    • Ferrite (e.g., Black/Dark Grey): High permeability, best for transformers and noise filtering (ferrite beads), but saturates easily.
  3. Winding Technique: For best results, spread the turns evenly around the entire circumference of the toroid. Leaving a large gap can increase leakage inductance.
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