Practical
Electronics
Volume 55. No. 04
April 2026
ISSN 2632 573X
Contents
Projects and Circuits
Versatile Battery Checker by Tim Blythman
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This useful tool allows you to check the condition of all manner of batteries, including
Li-ion, LiPo, lead-acid, SLA, AGM, alkaline and zinc-carbon types. It can test 12V or
24V vehicle starter batteries, 9V batteries, plus D, C, AA and AAA cells and more.
33
Power Rail Probe by Andrew Levido
This is one of those pieces of test equipment that you don’t really need, until you do. In
conjunction with an oscilloscope, it allows the accurate measurement and evaluation of
ripple, switching noise and transients riding on DC supply rails.
60
The Pico 2 Audio Analyser by Tim Blythman
Using an inexpensive Raspberry Pi Pico 2 microcontroller board and not much else,
we can generate and analyse audio signals. It has oscilloscope and spectrum modes
and can run a sweep to plot a frequency response or perform harmonic analysis.
Series, Features and Columns
Teach-In 12.6: the World of Wireless by Mike Tooley
This month, we will be looking at the principles and techniques that underpin a
range of useful RF measurements, including voltage, power and frequency. Our
Hands-On project is a handy RF probe.
4
24
Power Electronics, part one by Andrew Levido
Power electronics broadly describes circuits designed to handle electrical energy. We
will explore power electronics in this new series, including some practical examples.
Max’s Cool Beans by Max The Magnificent
40
Weird & Wonderful Arduino Projects, part 16: etching sketches & snake shenanigans
After looking at one reader’s console built from MDF, we will first create an electronic
Etch A Sketch, then start implementing the classic arcade game Snake.
48
Circuit Surgery by Ian Bell
Measuring circuit frequency response using a PC sound card, part 7: op amp
output impedance & compensation. This instalment considers the effect of adding
a series output resistor on stability, especially when driving capacitive loads.
58
Techno Talk by Max the Magnificent
From visible mechanisms and fixable machines to sealed laptops, microscopic sensors
and optical MEMS. Join me on a ramble through modern technology as it grows more
powerful and more mindboggling.
69
Audio Out by Jake Rothman
Absolutely phased out (all-pass filters, part one): most people know about low-pass,
high-pass, band-pass and notch filters; so what are all-pass filters and are they useful?
Regulars and Services
Made in Australia & the UK.
Written in Britain, Australia,
the USA and Ireland.
Read everywhere.
© Silicon Chip Publications Pty Ltd 2026
Copyright in all drawings, photographs, articles, technical
designs, software and intellectual property published in
Practical Electronics is fully protected, and reproduction
or imitation in whole or in part are expressly forbidden.
The May 2026 issue of Practical Electronics will be
published on Thursday, 2nd of April, 2026 (see p80).
Practical Electronics | April | 2026
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