LC meter

[giuseppem94]

hello, I'm starting to build an IDX Pro and I wanted to build a induttometro to accurately measure the inductance of the coils;
On the internet I found many plans, but I seem to have understood that the resonant frequency of the coil must be greater than the frequency with which it will be analyzed, as a result many projects are not "good",
you could recommend a good lc meter to measure the inductance of the coil metal detector?


ps I know to program the pic, I do not have an oscilloscope

[golfnut]

Yes, if the measurement kit uses an interrogation frequency that is close to the self resonant frequency of your coil - you can get odd results.

If the measurement frequency is adjustable, select the one closest to the operating frequency for your coil.


I have used digital Hewlett Packard L bridge for a TGSL coil for 14kHz.

With the kit set at 1kHz - no problem good reading
With the kit set at 10kHz no problem same, good reading

With kit on 100kHz the readings were wildly different and going positive and negative! and varying.


I used other measurment kit and could see my coil was resonant at about 98kHz

[giuseppem94]

you could tell me the link of a lc meter with pic and related code written in C so as to use a 16F688 that I have at home?

[Finderskeepers]

l.c. meter.zipjust finished a lc meter that uses a pic16f628. Got the schematic and hex code from https://sites.google.com/site/vk3bhr/home/index2-html and expalins how to calibrate the meter.
It is simple to make and is pretty accurate & easy to use.
I have attached photos of my unit and a zip file with pcb artwork, pcb layout, schematic and code.

[joop]

LC meters with a simple microprocessor are great for Metal Detector projects. There are also several LC meters on the internet which use the Arduino platform, see Google. Very easy to build!