Below is online calculator for calculating inductance or number of turns required to make iron core and ferrite toroid inductor. There are two calculators- the first one uses the inductance index(inductance factor) and the other uses the geometry of the toroid.
A. Using Inductance Factor \(A_L\)
Iron Powered Toroid Inductor
The formula for Iron Powered Toroid Inductor used above is given below.
Inductance(L): \( L_ = \frac{A_L N^2}{10,000} [\mu H]\)
Number of Turns(N): \( N = 100 \sqrt{\frac{L_{\mu H}}{A_L}} \)
where,
- L is inductance in uH
- \(A_L\) is inductance factor(inductance index) in \(\mu H\) per 100 turn squared
Ferrite Toroid Inductor
The formula for Ferrite Toroid Inductor used above is given below.
Inductance(L): \( L = \frac{A_L N^2}{1,000,000} [mH]\)
Number of Turns(N): \( N = 1000 \sqrt{\frac{L_{mH}}{A_L}} \)
where,
- L is inductance in mH
- \(A_L\) is inductance factor(inductance index) in mH per 1,000 turn squaredB. Using Toroid Geometry
Formula Used:
Inductance: \( L = \frac{4 \pi N^2 \mu_i n A_e}{l_e}[nH] \)
Effective Length: \( l_e = \frac{ \pi (D-d)}{ln(\frac{D}{d})} [cm^2]\)
Effective Area: \( A_e = 0.5 n(D-d) h[cm]\)
where,
- L is inductance in nH
- D is the outer diameter in cm
- d is the inner diameter in cm
- h is the height in cm
- \(A_e\) is the effective area in \(cm^2\)
- \(l_e\) is the effective length in cm
- \(\mu_i\) is the initial permeability
- N is the number of turns- n is the number of stacked cores
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Tags:
inductor calculator