DIY Inductor Calculator

[mac]

I needed to estimate the inductance of a transformer for a wah wah without any special instrument.
I came up with this:



It's a simple LC oscillator connected to a LM386 amplifier chip.
Use different C1 depending on the inductor L1.
You can set your own oscillator and amplifier but the equations could be different.
C2 and the volume pot did not alter the oscillation frequency, at least not that much to be audible...
Play your guitar until you match the resonant frequency, check the table and do the maths.

mac