DIY LC Meter

[AndyOne]

I found this whilst surfing, I think it might be useful.

http://electronics-diy.com/lc_meter.php

Andy.

[Katanadon]

thank you i cant wait to start on this.

[quax]

Hi, I have built one, works great.

I test my DIY-outrunners, if I have the same turn-count (inductivity) on each phase.

Ciao
Bernhard

[Gary Warner]

Slick project Andy. Thanks for the link.

Gary
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[tolik212]

Hello guys ,
Anybody still have the wirmware file for PIC16F84 used in this project ?

[jomland]

Hi.
I think this link is what you are looking for.

http://ironbark.bendigo.latrobe.edu.au/~rice/lc/

Jon

[weber_alejandro]

Hi.
I think this link is what you are looking for.

http://ironbark.bendigo.latrobe.edu.au/~rice/lc/

Jon

I build this one, and really rules!
I just use a 16x2 display because can't find the original 16x1

Here, my PCB version, have a little mistake, the jumper who supply the 5v to the PIC is pointed to 0v instead. Fixing this the circuit works great.
http://www.e-radiocontrol.com.ar/images/lcmeter_pcb2.gif
http://www.e-radiocontrol.com.ar/images/lcmeter_comp2.gif

Eagle Archive (http://www.e-radiocontrol.com.ar/?download=lcmeter.brd)

Some pics of my LC Meter
http://www.e-radiocontrol.com.ar/images/lcmeter_foto10.jpg
http://www.e-radiocontrol.com.ar/images/lcmeter_foto7.jpg
http://www.e-radiocontrol.com.ar/images/lcmeter_foto8.jpg
http://www.e-radiocontrol.com.ar/images/lcmeter_foto9.jpg

[yctseng]

This L/C meter is quite useful in my DIY RF amd Receivers..

[78L05]

I don't understand how do you mean there's error. What I must do on your PCB?
Please post your PCB in .PDF version in 1:1 (real size), and HEX code for PIC16F84.
Can you add tho pins for LCD bakclight, one pin to ground, and resistor from + to another pin.
Thanks!!!

[Acetronics]

Alexandro means the pic is powered ( say GROUNDED !!! ) with 0 Volts !!!

the strap ( jumper ) laying under the 16F84 is wrong ... replace it by a wire connected from Pic pin 14( VDD ) to + 5v ...

Alain

[78L05]

Thank you Alain. Can someone post PCB in pdf format in real size (1:1)?

[Acetronics]

1) Eagle just can draw it for you ...

2) Moreover just visit the different links provided ...

Alain

[fm_head]

Hi,
Can anyone tell me if the specifications of this reed relay are correct for this circuit ?

http://www.daiichiparts.com.hk/product/reed/rl108n_700.htm

can I use it to build this (http://electronics-diy.com/lc_meter.php) lc meter ?

regards.

[78L05]

I don't know how to make a PCB in Eagle. I installed Eagle 5.6.0. Professional.

http://www.e-radiocontrol.com.ar/?download=lcmeter.brd

When I open this Eagle show me component side inside of solder side. How to make solder side from component side?

[78L05]

In my place in elektroshops there isn't inductor 82uH, can I replace this with something another inductance? Thanks!

[jdelca]

Mine is working with 100 uH, change only affects to the measuring range, accuracy is still the same as the circuit self calibrates.

[78L05]

Mine is working with 100 uH, change only affects to the measuring range, accuracy is still the same as the circuit self calibrates.

And when is used 100uH is measuring range bigger or smaller than is used 82uH? Thanks!

[jdelca]

And when is used 100uH is measuring range bigger or smaller than is used 82uH? Thanks!

Looking to how it works it seems the range will be a bit smaller and shifted to the low side (lower min value, lower max value), as example the frequency at calibration is 356Khz instead of 393Khx with the 82uH

One point I remember was critical for the accuracy is the quality of the installed capacitors, I ended using 2.5% styroflex with the following results with some "calibrated" coils

12 uH ----------- 11.95 uH
33 uH ----------- 32.87 uH
1000 uH ------- 1.034 mH

However with the first capacitors I installed:

12 uH ------------- 10.70 uH
22 uH ------------ 17.56 uH
33 uH ------------- 29.79 uH
1000 uH ------------ 951.4 uH


Hope it helps

[78L05]

I made LC meter and it doesn't work. On display is 00000000, and relay isn't active at all. And when I put J2 jumper, than relay active herself and for 2 seconds he turn off and display 0000000. What shall I do???
I didn't conect the part for changing "inductance-capacitance" I hope that this isn't important.

Edit:

When I remove all jumpers, relay on and for one seconds relay off and display: over range. What's the problem??

I programmed PIC with all disabled options, only PWRT was enable, and oscilator: XT.

[jdelca]

The 0000000 reading sounds like the LM311 is not oscillating, exactly what components you have not installed ?

Do you have access to an osciloscope ? if yes, check LM311 output (pin 7) any signal ?

[78L05]

I used 100uH and 1000pF, when JUMPER between ground and PIN 12 of PIC16F84A is connect display shows:00000000, and when the JUMPER isn't connect display shows: Over Range. I didn't connect switch for L/C mode.

[jdelca]

The jumper at pin 12 makes the pic to display the raw frequency of the oscilator without applying any calculation.

To me, this indicates the LM is not oscillating, double check the oscillator circuit.

[78L05]

Please, can someone draw how to connect switch in Paint? It's 2x3, just like @weber_alejandro on pictures.