After finishing my last project – “Simple LC meter“, there were some discussions in the forum I am a member of, that ability to measure electrolytic capacitors would be very useful in this type of device.
I searched the Web and found a very cute project named LCM3 on this Hungarian site: hobbielektronika.hu . I love Hungarian rock since my school days, but I don’t know a word in Hungarian . So, I searched the Web again, this time for this specific project and found a Russian forum where the project was discussed in details and I got more useful information about parts, settings and so on.
Advanced LC meter – [Link]
Here is another piece of laboratory equipment – LC meter. This type of meter, especially L meter is hard to find in cheap commercial multimeters.
Schematic of this one came from this web page: https://sites.google.com/site/vk3bhr/home/index2-html
It uses PIC microcontroller 16F628A, and because I recently acquired a PIC programmer, I decided to test it with this project. Following the above link you will find the original schematic, PCB, source and HEX files for programing the microcontroller and detailed description.
Simple PIC LC meter – [Link]
Le Hung writes:
LCFesR 4.0 unit is a precise, wide range LC / LCF / LCR / ESR meter (tester / checker) that measures inductance (L), capacity (C), frequency (F), small resistance (R) and equivalent series resistance (ESR) of a capacitor inside an electronic circuit (in-circuit). The meter can be built easily with one- or double-sided PCB and available electronic components (DIY). It’s functions are base on an further developed AVR ATMega88PA-PU microprocessor. Professional KIT is also available.
LCFesR 4.0 meter – LC / LCF / LCR / ESR meter – [Link]
Sergei Bezrukov writes:
This was my last weekend project, which I needed to complete urgently. The LC-meter design is based on a front-page article in Everyday Practical Electronics magazine, no. 3, 2010. A similar project is also published here. Assembled for a very occasional usage, I did not put it into a case.
LC meter – [Link]
All I do is use the LM311 square wave output as pulses to a 16bit counter, and another 100mS periodic timer to count how many pulses per 100mS interval, to calculate the oscillation frequency. BTW, the PIC32 is running off a 16MHz crystal. I average the results from 5 consecutive readings, so I have a 0.5second measurement repeat rate. Good enough. It seems to be accurate enough for my needs, which is basically identifying components that I salvage, or coils that I wind myself.
LM311 oscillator based LC meter – [Link]
For the growing interest about miniature SMT inductors, we bring you series of Fastron SMT inductors 0805AS and 0805F. These are quality wire-wound components, suitable even for very high frequencies.
It isn´t very long ago, when the best high frequency inductor was a relatively big coil with the air core, created only by few turns of the copper wire. Partially it is still true, as the laws of the physics don´t change, but in respect to nowadays miniaturisation requirements, the usage of SMT coils is in many applications more convenient. Moreover, miniature coils feature much smaller mutual influence caused by their own magnetic field, what enables to further miniaturize dimensions of a device. Last but not least, an inductor is a very effective, almost lossless filter, on the places we need to eliminate interference, or to prevent its penetration into other parts of a device. That´s why is their usage as an LC filter actual in almost every device with processors, logic gates and similar components.
Fastron 0805AS are coils with the ceramic core, which has properties – from a magnetic aspect, very near to the air, that´s why this series has a relatively high Q factor, high self resonant frequency and a high linearity. They are available in inductances from few nH up to 10 uH. Thanks to their very good HF properties, they are also suitable into various HF parts of receivers, transmitters, circuits for signal processing, input stages of AD converters, HF filters etc., up to frequencies of few GHz. Read the rest of this entry »
Nowadays is so easy to build precision digital LC meter with LCD display and microcontrollers. But, what about 1997? There is my first very precision ANALOG LC METER. Look at this, but do not fall in love in retro princess from past!! The analog LC-meter project (AP-LC1) have more then 3% accuracy. Really! There is no balanced bridge, or very expensive components inside.
We read the value on 100mikroA DC instruments with accuracy scale of 2%. It is very simple, only one integer circuit (HEF40106BP). I used 5 from 6 Hex Schmitt Trigger organized like a independent oscillators: 10Hz, 100Hz, 1KHz, 10KHz i 100KHz. If we want to use a higher frequency (1MHz) we must find original transistor BSX20 instead BF198.
Analog LC Meter, back to the past 1996 – [Link]
Some time previous to getting my ham license, I was at a friends house who showed me an LC (inductance) meter built from a kit. It was based on a PIC16C22A, and I certainly do like the PIC mcu’s, but decided I would embark on the task of re-engineering my own that uses an Atmel AVR chip, the Atmega168. It’s been a journey. Also, I am giving away for free the schematics, firmware, and source code as open source under the GPL.
Inductance meter – [Link]
This project is an Inductance and Capacitance Meter using Microchip’s PIC18F2550 connected to USB. Source code is available on the link below.
PIC18F USB LC Meter – [Link]
This projects talks how to build an inductance and capacitor measuring tool based on PIC16F870 microcontroller. On the project’s page you can also learn about the theory behind measurements and how microcontroller calculates inductance and capacitance. Main hardware of the consists of a common LCD display, PIC16F870 mcu and LM311 oscillator. Design details, schematics, software and PCB can be found on the link below. Expected accuracy is +/- 1% of reading +/- 0.1pF or +/- 5nH
LC meter with PIC16F870 – [Link]