Thread: INDUCTANCE AND CAPACITANCE METER USING PIC...LC METER

NEED SCH PCB AND WAT NOT.....

look at

h**p://www.qsl.net/iz7ath/web/02_brew/21_LCMeter01/

its works fine

regards
albert

Try this one, it uses a PIC, it is very accurate and simple.
I had built it and works fine.

Code:

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

There are also some other projects on the above page.

dude i know better site than those...use a google search....i have a new problem....i cannot get accurate value capacitors or inductors do u have any method to minimize the error....

Originally Posted by roykyn

dude i know better site than those...use a google search....i have a new problem....i cannot get accurate value capacitors or inductors do u have any method to minimize the error....

The LC meter (that uses the PIC) requires two things to be accurate.
1 a 4mhz crystal (the PIC is basically a frequency counter)
2 an accurate capacitor for calibration.

If you have access to a capacitor meter then simply hand check a few.

Some versions of the L/C meter have a frequency display to tell you the free running frequency of your tank circuit. Still you need to know at least one variable (inductor or capacitor value) to modify the software for calibration.

If you have no access to those two somewhat common parts then your L/C meter will be inaccurate and you have no way to know by how much.

You need the tools. Else your SOL.

So, the beautiful picture showing a 0.1pF it's just a measurement error ?
:D
How many pF has the measuring cable connected to this capacimeter ?

I've built the LC meter project, it works very well. The tank circuit is the secret.

Here's the FAQ on it. If you KNOW the inductor value you could in theroy skip the calibrate mode by storing caibration data in EEPROM.
http://ironbark.bendigo.latrobe.edu....ce/lc/faq.html

You could not do it with a 16F84 (not enough ROM @ 1K) a 16F628A would be a better choice. They have the source for both on this site.
http://ironbark.bendigo.latrobe.edu.au/~rice/lc/

Here's another nifty project and it claims to do caps and inductors too.
http://members.cox.net/berniekm/super.html

blueroomelectronics guy....thank u for ur interest.....i do have a freq counter built on pic 16f72...i am using pic 16f72 for the lc meter tooo.....i am not getting the concept....i mean how the software works ....then i can write my own ....

blueroomelectronics,

i have built the meter described at

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

using PIC16F84A with good results also.

roykyn,

Mr. Rice has a good explanation on how it works. Basically, a comparator is wired to be a free running oscillator (whose frequency is a function of the capacitor or inductor to be measured).

The PIC software implements a frequency counter. Mr. Rice has the source code on the website. He measures frequency by taking the input on RA4 and configures that pin to increment TIMER0 on the falling edge. He then waits a specific time and uses the change in TIMER0 to determine the frequency, converts it to a capacitor/inductor value, and displays it on the LCD. He has equations for the conversion from frequency to component value (for the oscillator used) on the website as well.

-Jonathan