LC-Meter with resonance calculations

[Joit]

Hello,

I found a nice circuit for calculating the resonance frequency also the capacity from a Coil.
It works with your line-in plug from a soundcard and a lm311 chip.
The original Circuit can be found here.
Spulen messen mit der Soundkarte - Michael Gaedtke
Translated Link

This is what the program looks like what you need to download from the link below.
I did measure here the bigger Coil from a microwave oven.


Here is the circuit itself.

Have fun.

[mikrovolt]

another sound card scope
Electronics: Soundcard-Oscilloscope

a bat detector extends the range set the division on the 4024. should do 100khz. don't need the
transducer. LM386 amplifier makes the peak resonance extremely sensitive.
probably too much precision at first. later with much labor it can tune to ultra resonant frequency.

Build a Simple Bat Detector

for the output mix the audio output with crystal frequency using NE602 should be fairly accurate.
602 needs 200mV signals and will go to 200 Mhz