Toroidal Inductor Calculator

Air core inductors use air (μr = 1) as the core material, providing linear characteristics but lower inductance. Magnetic core inductors use ferrite or iron powder (μr > 1) to significantly increase inductance but may have nonlinear characteristics at high currents.

The relative permeability depends on the core material. Common values: Air = 1, Iron powder = 10-100, Ferrite = 1000-5000. Check the manufacturer's datasheet for exact values, as μr varies with frequency and flux density.

The AL factor represents the inductance per turn squared (nH/N²) and is a core-specific parameter. It allows quick calculation of inductance: L = AL × N². Higher AL values mean more inductance for the same number of turns.

Wire length equals the number of turns multiplied by the mean turn length. The mean turn length is approximately π times the average of inner and outer diameters: MTL = π × (Do + Di) / 2.

Toroidal inductors offer superior magnetic field containment, reducing electromagnetic interference. They provide higher inductance per unit volume, lower leakage inductance, and better coupling between windings compared to solenoid or air-core inductors.

Calculation accuracy depends on core material uniformity, frequency of operation, current levels, and winding distribution. At high frequencies, parasitic capacitance and core losses become significant. Temperature also affects permeability.

Wire gauge selection depends on current capacity, skin effect at operating frequency, and physical fit within the core window. Use AWG charts for current ratings and ensure the total wire cross-sectional area doesn't exceed 40-60% of the core window area.

Yes, but layered windings increase leakage inductance and parasitic capacitance. Single-layer windings provide the most accurate inductance calculations. If multiple layers are necessary, distribute turns evenly around the core circumference.