Formula for calculating the inductance of the coil:
1. According to the circular CORE, the following formula can be used: (IRON)
The L=N2.AL L= inductance (H)
H-DC=0.4 PI NI / L N= the number of turns of the coil (ring)
AL= induction coefficient
H-DC= DC magnetizing force I= by current (A)
The l= path length (CM)
L and AL values, can refer to Microl table. For example: in T50-52 material, the coil 5 and a half circle, the L value is T50-52 (say OD is 0.5 inches), checking the table and its AL value is about 33nH
L=33. (5.5): 2=998.25nH = 1 H
When the current flowing through the 10A, the L value changes from l=3.74(look up table)
H-DC=0.4 n NI / L = 0.4 * 3.14 * 5.5 * 10 / 3.74 = 18.47 (look up table after)
To understand the L value decreased degree (i%)
2. Introduce an empirical formula
L= (k* 0* s*N2*S) /l
Among them
Mu 0 is the permeability of vacuum =4 PI *10 (-7). (10 minus seven party)
S for the relative permeability of inner coil core, hollow coil s=1
N2 is the number of square coil
The cross-sectional area of the S coil, the unit square meters
L the length of the coil, the unit for metres
The K coefficients, depending on the coil radius (R) and the ratio of the length(L).
Inductance calculated unit for Henry.
The table of K values
2R/l K
0.1 0.96
0.2 0.92
0.3 0.88
0.4 0.85
0.6 0.79
0.8 0.74
1 0.69
1.5 0.6
2 0.52
3 0.43
4 0.37
5 0.32
100.2
200.12
