Practical
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re air or odification o co
ercial e ui ent or the incor oration
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Projects and circuits
All reasonable precautions are taken to ensure that the advice and
data given to readers is reliable. We cannot, however, guarantee
it and we cannot accept legal responsibility for it.
A number of projects and circuits published in Practical Electronics
employ voltages that can be lethal. You should not build, test,
modify or renovate any item of mains-powered equipment unless
you fully understand the safety aspects involved and you use an
RCD (GFCI) adaptor.
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commencing any project in a back-dated issue.
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Volume 51. No. 4
April 2022
ISSN 2632 573X
Editorial
It’s all about power
Jake Rothman’s opening line in this month’s Audio Out column
– ‘Audio lives or dies by its power supplies…’ – is of course
aimed at audio electronics fans, but it’s a good reminder that all
our projects, designs and explorations in the world of electronics
come to nothing if the battery, PSU, supply or whatever source of
electrical power you are using isn’t up to the job.
We do run plenty of power supply projects, but I hope you’ll take
the time to read through Jake’s latest design. Even if audio is not
your main focus, it’s an excellent example of elegant analogue
design that could be used in many other applications that need
stable power with low levels of ripple and hum. As always, Jake’s
designs use inexpensive, readily available components to get
excellent results that anyone can build.
Advancing with Flowcode
Martin Whitlock returns in this issue with another in-depth
exploration of how to use Flowcode. You’ll recall from his
January and February articles that Flowcode is a flexible and
intuitive programming environment that lets you program a
PIC16F88, Arduino Uno and many other PICs/microcontrollers
without having to use assembler or C – you just draw flowcharts
of the intelligent process that you want to implement. This
month, he shows you how to create a simple electronic
thermometer and tackles two common requirements for
microcontroller users – reading an analogue voltage and writing
to a 16x2 character display.
A nice piece of serendipity is that this month’s Circuit Surgery
looks at the LM35 temperature sensor IC. This is exactly the same
device used in the Flowcode mini project, so there’s analogue
and digital focus on one useful and easy-to-follow project.
Projects, projects, projects
Speaking of projects, in addition to our regular columns, this
month we start three fascinating designs for you to build – a
useful High Current Battery Balancer, a handy 64-key MIDI
Matrix and a top-quality Digital FX Unit. Plus, Phil Boyce
explains all you need to know to build a Micromite-based iButton
Electronic Door Lock.
Lots to keep you busy!
Keep well and stay healthy
Matt Pulzer
Publisher
Transmitters/bugs/telephone equipment
We advise readers that certain items of radio transmitting and
telephone equipment which may be advertised in our pages
cannot be legally used in the UK. Readers should check the law
e ore uying any trans itting or tele hone e ui ent as a fine
confiscation o e ui ent and or i rison ent can result ro
illegal use or ownership. The laws vary from country to country;
readers should check local laws.
Practical Electronics | April | 2022
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