Elektor_Mag_-_January-February_2021

lektor January & February 2021 73

When done calibrating a channel, press ->OK. Then the calibration

data are stored on the satellite board of the selected channel.

As far as I’m concerned this project is finished. There will be no more

large additions or changes. But of course, I will answer any question.

This article is based on the information presented on the Elektor Labs

project page at [2]. On this page, more detailed information on this

Power Analyzer including software, PCB design files and BOM can be

found or downloaded. The Eagle CAD-files on Elektor Labs are up to

date with the most recent changes, but newer versions of the PCBs

have not been built and/or tested!

190133-B-01

How to calibrate and adjust
From the Main Screen you can go to the Calibration screen. You can
choose between calibrating the touchscreen and calibrating the
channels. At the first start up the touchscreen calibration procedure
will automatically be presented. Use a pencil or wooden stylus to
calibrate (and use) the touch screen.

In the channel calibration you will first be prompted to select a channel.
Then the software enters a screen where voltage, current and frequency
can be measured and adjusted. In this screen the automatic ranging
for V and I is disabled, which will make it easy to adjust the calibration
for each range. With the arrows (< and >) you can change ranges and
adjust the measured value.

The best method to adjust the frequency is to connect a digital oscil-
loscope to TP8 (signal) and TP2 (GND) on the satellite board of the
selected channel. Adjust the visible pulse width to 35.00 ms with
the arrows on the frequency line. Second best method to adjust the
frequency is to use a signal source with a calibrated frequency of 50
or 60 Hz and adjust the reading to 50.00 or 60.00 Hz. The reading
can vary ±0.5 %.

Figure 6a: Measurement of a transformer in

saturation, FFT of current.

Figure 6b: Measurement of a transformer in

saturation, voltage and current.

Figure 6c: Measurement of a transformer in

saturation, voltage and power.

[1] AC/DC Power Meter: http://www.elektormagazine.com/magazine/elektor-201509/28070

[2] Power Analyzer: http://www.elektormagazine.com/labs/power-analyzer

[3] FFT calculation: http://www.nicholson.com/dsp.fft1.html

[4] The Scientist and Engineer’s Guide to Digital Signal Processing, by Steven W. Smith, Ph.D.: http://www.dspguide.com/pdfbook.htm

WEB LINKS

related products

> Microcontroller Basics with PIC

http://www.elektor.com/microcontroller-basics-with-pic

Questions or comments?

Do you have questions or comments about his article? Email

the author at [email protected] or contact Elektor

at [email protected]

Contributors

Idea, Design, Text and Illustrations: Wil Dijkman

Schematic: Patrick Wielders

Editor: Luc Lemmens, CJ Abate

Layout: Giel Dols