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]
This is PIC16F628 and pic16f84 base inductance/capacitance meter design by Phil Rice VK3BHR.Measuring range is from 0 to >0.1uF for capacitance and 0 to >10mH for inductance.Expected accuracy is +/- 1% of reading +/- 0.1pF or +/- 10nH.This project is a combination of two stolen designs.The oscillator design originally came from the AADE LC meter web page. It uses an LM311 comparator with positive feedback to make a parallel LC oscillator with digital output. It seems to oscillate readily over a wide range of L and C values. Hopefully, it follows the “well known formula for resonant frequency”.The frequency measuring part is a cut down version of the September 2002 Frequency Meter article from Amateur Radio magazine. The original idea for this came from the web pages of Eamon Skelton, EI9GQ. [via]
Surprisingly Accurate Digital LC Meter - [Link]
That’s a really nice LC Meter Based on the AVR Microcontroller. It calculates and displays L and C from oscillation frequency using reference components. No relays, no range switching, a minimum of controls. And it is pretty accurate too! The 2 line x 16 character LCD shows the calculated inductance and the oscillation frequency. The frequency might be of interest because inductors with cores can appear to vary in inductance with changing test conditions.
A Pretty Good LC Meter Based on the AVR Microcontroller - [Link]