A SURPRISINGLY ACCURATE DIGITAL LC METER”I DIDN'T EXPECT IT TO WORK SO WELL!”

A design byPhil RiceVK3BHR

Available in Different Languages on the web.

Author Language & Web Site Marek SP7DQR Polish

http://sp7dqr.waw.pl/lcmeter_pl.html Aleksandr Buyevskiy Russian

http://www.cqham.ru/lc_meter.phtml Patrick TK5EP French

http://tk5ep.free.fr/tech/lcmeter/fr/lcmetre_f.php Volker SM5ZBS

German http://www.janson-soft.de/lcmeter/lcmeter.htm

FeaturesPic Based design with software calibration.

http://en.wikipedia.org/wiki/PIC_microcontroller

Low Part Count.Simple to use.Battery Powered.Locally available parts.Claimed measuring range:

Capacitors - 0.0pF to about 0.1uFInductors - 0.0uH to somewhere

over 10mHAll Thourgh Hole and NO SUFACE MOUNT

Claimed measuring range

Small measurements are inaccurate,because of quantising error.

Capacitors - 0.0pF to about 0.1uF

Inductors - 0.0uH to somewhere over 10mH

The Mathematicsbehind the scenes.

Parallel LC oscillator& Frequency Meter

Origional Design

Improved Version 2https://sites.google.com/site/vk3bhr/home/index2-html

It differs from the original in that:

A 16F628 PIC is used. This has internal comparator, which means the LM311 is no longer needed.

Software calibration is used. The finished meter can be calibrated against "any" accurate capacitor within the range 100pF to about 10000pF.

Component Layout

Variations in Artwork

http://kc7zow.tripod.com/hamradio/id8.html

http://f6bon.albert.free.fr/LCMETER2.pdf

Variations in Schematics

http://www.aade.com/manuals/lcm2b%20kit.pdf

http://f6bon.albert.free.fr/lcsch.pdf

Variations in Implementation

http://kc7zow.tripod.com/hamradio/id8.html

http://www.aade.com/lcmeter.htm

http://py2wm.qsl.br/LC_meter/LC_meter-e.html

http://f6bon.albert.free.fr/lcmetre.html

http://www.pi4zlb.nl/Zelfbouw/LC-meter.html

http://xavier.fenard.free.fr/LCMeter.htm

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

http://www.marc.org.au/

http://py2wm.qsl.br/Gravador_PIC/pic-programmer.html

Build Process

Redrew schematic in ExpressPCB with Mouser Part numbers.

Redrew layout with changes for new parts.

Extracted Bill of Materials from the schematic.

Upload to Mouser and make any changes for items you have.

Print PCB layout and etch the circuit board (Iron on process).http://www.staples.com/Staples-Color-Laser-Paper-Glossy-8-1-2-inch-x-11-inch/product_633215

This is still a work in progress…

Express PCB Schematic

Express PCB Layout

Bill of Materials

Front Panel Artwork& Drilling Template

Board by Chris Hood, KE5SBP

Completed Board and Display

Drilled Case and Mounting Hdw.

Completed Meter