Load its inductance is calculated as follows: Coil formula
Impedance (ohm) = 2 * 3.14159 * F (operating frequency) * Inductance (mH), set the required 360ohm impedance, thus:
Inductance (mH) = impedance (ohm) ÷ (2 * 3.14159) ÷ F (operating frequency) = 360 ÷ (2 * 3.14159) ÷ 7.06 = 8.116mH
Accordingly wound coils can be calculated:
Number of turns = [inductance * {(18 * circle diameter (inches)) + (40 * Cycle Length (inches))}] ÷ circle diameter (inches)
Number of turns = [8.116 * {(18 * 2.047) + (40 * 3.74)}] ÷ 2.047 = 19 laps

Core inductor formula
Core inductor formula: L (mH) = (0.08DDNN) / (3D + 9W + 10H)
Coil diameter D ------
N ------ turns
d ----- Wire
H ---- coils height
W ---- coils width

In mm and mH. .
Hollow coil inductance calculation formula:

l = (0.01 * D * N * N) / (L / D + 0.44)

Coil inductance l Unit: microhenry
Coil diameter D unit: cm
The number of turns N units: Turn
The coil length L Unit: cm

Frequency inductor-capacitor formula:

l = 25330.3 / [(f0 * f0) * c]

Operating frequency: f0 unit: MHZ this question f0 = 125KHZ = 0.125
Resonant capacitor: c unit: PF This question Jianyi c = 500 ... 1000pf may first decide on their own, or by the Q
Value determination
Resonant inductor: l Unit: microhenry
Inductance of the coil is calculated
Author: posted inductance of the coil is calculated from: Reproduced Hits: 299

1. For ring CORE, the following formula can be used: (IRON)

L = N2. AL L = inductance (H)
H-DC = 0.4πNI / l N = number of turns (turns)
AL = inductance
H-DC = DC magnetizing force through the current I = (A)
l = magnetic path length (cm)
l AL value and size, can refer Micrometal table. For example: In T50-52 material, coil 5 laps and a half, its L value T50-52 (represented OD of 0.5 inches), the look-up table its AL value of approximately 33nH

L = 33. (5.5) 2 = 998.25nH ≒ 1μH
When electric current flows through 10A, the L value changes by l = 3.74 (look-up table)
H-DC = 0.4πNI / l = 0.4 × 3.14 × 5.5 × 10 / 3.74 = 18.47 (after a look-up table)
L value decreased to understand the extent of (μi%)

2. Introduce an empirical formula
L = (k * μ0 * μs * N2 * S) / l
among them
μ0 is the vacuum permeability = 4π * 10 (-7). (10 minus seven square)
relative permeability μs is inside the coil core, μs = 1 when the air-core coil
N2 is the number of turns squared
Cross-sectional area S of the coil, the unit is square meters
l coil length in meters
k factor, depending on the coil radius (R) and length (l) ratio.

Calculate the inductance Henrys.

k value table
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           0.69
1.5           0.6
2.0           0.52
3.0           0.43
4.0           0.37
5.0           0.32
10            0.2
20            0.12