(No magnetic coupling between coils)
Figure bellow shows how the coils are wired. The next formulas are used to calculate the equivalent (L) inductance.
Formula 1
1/L = 1/L1 + 1/L2 + 1/L3 + … + 1/Ln
Where:
L is the equivalent inductance in henry (H)
L1, L2, L3...Ln are associated inductances in henry (H)
Note: Submultiples of the henry (uH or mH) can be used.
Formula 2
For two coils:
L = [ (L1 x L2) / (L1 + L2) ]
Application Example:
What is the equivalent inductance of two coils, one with in inductance of 40 mF and the other 60 mH, wired in parallel?
Data:
L1 = 40 mH
L2 = 60 mH
L = ?
Using formula 2:
L = (40 x 60)/(40 + 60) = 2 400/100 = 24 mH
