Inductor geometry and core estimates
Wheeler single-layer air coil, AL core or gap-dominated core with flux and wire estimates.
Development preview. Check the assumptions below before relying on a result. Calculations run in your browser.
How it calculates
Model: Air L(µH)=r²N²/(9r+10l), r/l in inches; AL: L=AL·N²; gap: L≈µ0N²Ae/lg; Bpk=LIpk/(NAe)
Assumptions
- Wheeler applies to a single-layer air coil. Gap model ignores fringing and core reluctance. AL is entered at the relevant bias.
- Wire area uses chosen current density, not an ampacity rating. Skin depth assumes nonmagnetic wire; proximity loss, core loss and winding fit are not calculated.
Worked example
These are the calculator's default inputs. Change any input above to recalculate.
Inputs
- Inductance model
- air-core
- Turns
- 20
- Air-coil mean radius
- 0.01 m
- Air-coil winding length
- 0.03 m
- Core AL
- 1e-7 H/turn²
- Core effective area
- 0.000025 m²
- Total magnetic gap
- 0.001 m
- Peak winding current
- 1 A
- RMS winding current
- 0.5 A
- Chosen winding current density
- 3000000 A/m²
- Skin-depth frequency
- 100000 Hz
- Wire resistivity
- 1.7241e-8 Ω·m
- Entered core flux limit
- 0.3 T
Results
- Estimated inductance
- 0.00000403796 H
- Core peak flux estimate
- Core flux not applicable T
- Copper area at chosen current density
- 1.66667e-7 m²
- Equivalent round-wire diameter
- 0.000460659 m
- Skin depth
- 0.000208978 m