http://www.dos4ever.com/inductor/inductor.html
1. Set the initial frequency of the signal generator to 20Khz with sinusoidal output
2. Adjust the frequency of the signal generator until the amplitude of the output signal (voltage trough the inductor) is half of the input signal from signal generator
3. when the frequency is found use the equation:
L = 4570/f where L is in μH, f is in kHz
Here: L = 4570/25.1=182μH
When the series resistance of the inductor is known, a more precise equation can be used:
L = sqrt(21.1+0.84*R-0.025*R^2)/f
where L is in H, f is in Hz
