Practical
Electronics
Volume 50. No. 11
November 2021
ISSN 2632 573X
Contents
Projects and Circuits
Dual Battery Lifesaver by Nicholas Vinen
This small board provides an easy way to protect rechargeable batteries from
being completely drained if a device is accidentally left switched on.
16
USB SuperCodec – Part 3 by Phil Prosser
Our SuperCodec is so good our Audio Precision system can barely measure its
distortion o it s ti e to ut it all together and get it u and running.
20
Thermometer Calibrator by Allan Linton-Smith
28
This simple thermometer checker will tell you just how accurate your thermometer is.
In some cases, you may even be able to adjust the thermometer to be more accurate.
I/O Expander Modules by Tim Blythman
34
o eti es hen or ing ith icrocontrollers you ust don t have enough ins to do
hat needs to e done. hat s hen you need e anders
Colour Maximite 2 (Generation 2) – Part 2
by Phil Boyce, Geoff Graham and Peter Mather
Building the latest, turbocharged iteration of our retro home computer.
42
The Fox Report by Barry Fox
VR/AR on tour in the UK
te ie i ic o the onth
uto ation
8
Techno Talk by Mark Nelson
On your marks…
10
Net Work by Alan Winstanley
This month, a warning that multiple global supply chain issues mean that
readers should plan ahead for Christmas. Plus, the unstoppable rise of apps.
12
Audio Out by Jake Rothman
nalogue ocoder
art
48
Circuit Surgery by Ian Bell
Capacitor Dielectric Absorption
52
a s Cool eans y ax The agnificent
lashing
s and drooling engineers
art
56
i by Mike Hibbett
evelo ent oard
62
Series, Features and Columns
192kHz, 24-bit
PIC n
art
Regulars and Services
Made in the UK.
Written in Britain, Australia,
the US and Ireland.
Read everywhere.
© Electron Publishing Limited 2021
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 December 2021 issue of Practical Electronics will be
published on Thursday, 4 November 2021 – see page 72.
Practical Electronics | November | 2021
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