The Shed - Electronics

Valve radios: Retro Radio magic

16 April 2025

The family gathering around the wireless to listen to the Friday evening programme may be a thing of the distant past but the beauty of those old valve-driven radios lives on in the dedicated work of Retro Radios.
Based in Dannevirke, Alister Ramsay works from an assortment of sheds, a garage and a container lovingly restoring old valve radios and radiograms. In a workshop redolent of the glory days of the 1940s to the 1960s, with nostalgic posters for Life magazine and a smattering of old cameras – another hobby is collecting old cameras – Alister works to a background of smooth jazz issuing from a variety of beautifully restored valve radios producing warm-toned music to set the mood.

Soldering tips part 2: Getting the job done

21 February 2025

We touched on some simple de-soldering methods in part one of this two-part series.
Just like other workshop tools, there is more than one way to achieve it and with less damage and frustration.
De-soldering involves removing the solder from the joint to either release the component or repair the solder joint. The aim is to do this with minimal damage to either part, but since you can generally replace the component, protecting the PCB is paramount.
SMT (Surface Mount Technology) is a whole other subject, and because of the design and density of the components, different tools are required.
De-solder or rework stations consist of a box controlling a heated tip and a vacuum pump. There are many manufacturers, but I’m only going to discuss some of the ones I’ve had experience with.
While the control box may have shrunk, there is a limit to reducing the handset. The handset consists of a tube to collect the solder and filters to absorb the flux residue. The tips are hollow and reach right through into the collection tube.

A video guide to creating electronic music part one

10 October 2024

Introduction to electronic music – part one – instructional video
Have you ever imagined yourself as a John Bonham or a Jimi Hendrix? The magic of electronic music means you can set up your own one-man band, create original masterpieces, or rearrange your favourite instrumental.
In this new series in The Shed magazine, Enrico Miglino shows just how easy this can be with advice on what tools and aids are needed to get you started.
This video is to accompany part one of the series published in the October/November 2024, issue 117.

Ponoko—a cut above the rest

25 June 2024

While laser cutters are now practical for home-build projects, they are not something that everyone will want to run. They take up bench space, need care and feeding, get expensive in large calibres, and if you don’t use one that often you might well be better off letting a company like Wellington-based Ponoko cut things for you.
Ponoko stock a wide range of materials and are experienced with using their laser cutters on them. Handy, but scarcely unique given the number of engineering outfits that are out there that’ll do pretty much the same thing.

Getting up to speed

14 December 2023

The ever rapid and constant development of electronics has had many positive effects for the sheddie, and one such example is the Variable Frequency Drive (VFD), which allows the speed of 3-phase motors to be electronically controlled with the bonus of adjustable speeds. Historically, continuously variable speed motor drives involved mechanical systems such as the Reeves drive, which is similar to a motor scooter CVT transmission where belt-drive pulleys can be varied in size “on the fly” and hence vary the drive ratio.
These and other transmissions were universally expensive, difficult to retrofit and inefficient. The increased use and falling prices have brought new and used VFD drives within the reach of the home user and have opened opportunities with industrial machinery that previously did not exist.

Video of the wooden fairground organ built by David Dilks

6 November 2023

The 320-pipe fairground organ that David made from scratch is visually and acoustically impressive. The array of beautifully crafted pipes, different shapes and sizes, the accordion-playing monkey, and the drums make quite the show. It’s hard to resist jiggling — but then David and wife Joy, both ballroom dancers, kick up their heels and show their form. Music is a big part of their life.

Electronics: Powerful stuff

2 November 2023

Everyone who dabbles with electronics or even automotive stuff will eventually find a bench power supply very handy. When I first started getting into electronics, they were large, expensive beasts, and very much out of the reach of hobbyists. There were a few kitsets provided by some electronic parts suppliers, but these tended to be limited in voltage and current.
If a hobbyist wanted an affordable adjustable supply, they usually had to make it. We even resorted to designing and making our own when I worked for Telecom. Commercial units were available but they didn’t suit our requirements, or budget.

Build a hydro power plant

15 June 2023

Ever thought of creating your own electricity? It’s a challenge a number of New Zealanders aspire to these days, as rising power prices and possible insecurity of supply bring out the Kiwi leanings towards independence and DIY.
And how to do it? A small stream, a broken washing machine, a shed and you’re away. Well almost.

Warning: boiling point!

25 May 2023

I own an American classic car and it comes with the usual 1960s instrumentation—speedo, fuel gauge but only warning lights for oil, alternator, and water temperature. The alternator light comes on when you turn on the ignition, but the water temperature light is designed to come on only when the water temperature reaches 120-125 °C which is usually too late.
To fix that, I have devised this program powered by an Arduino micro-controller that will operate the temperature light when the engine powers up and light it up again to warn the driver as the temperature approaches 100 °C. It uses a readily available sender that will fit most vehicles.

Arduino software for wipers and temp gauge projects

25 May 2023

Controller
I chose to use a shield (add-on board) to house all the parts for this project that allows the use of any standard Arduino and settled on a Seeeduino V3.0 and a Freetronics prototype shield as an inexpensive solution.
I used the controller and shield to for the previous variable wiper speed project for the car (“Wipe that classic windscreen,” Shed, Apr/May 2012). This second part uses the same controller and shield to do both tasks. The reader can either make one or both. The shield construction includes the extra parts (two resistors, one transistor, and one diode) and uses the “Start” button to do the “Normal” calibration.
Here are the two sketches (software) in these The Shed website’s two posts.

one combining water temperature light and variable wiper functions into one controller; and
one that just does the water temperature light.

Wipe, wipe that classic windscreen

19 May 2023

I own an American classic car and there are a few mod cons that are missing. I’ve added central locking because crawling over seats was a pain, but I thought the Arduino could add a few features that aren’t available in the shops. This is the first of two parts which uses the same piece of Arduino hardware to do two different tasks—run variable-speed wipers and a temperature gauge. Each can be used on their own as it makes no difference to the software

Hot water tune up

27 April 2023

Research tells us that around a third of all energy used in the average New Zealand home goes in heating water. Another third goes in room heating.
In our home the rooms are mainly heated free from the sun so the water-heating fraction of the total energy use is a lot more than a third. Most water-heating systems aren’t well tuned. Improving their efficiency usually brings significant cost savings, a welcome relief in the current economic climate. Often it’s easy and costs little to do.

Rescue those versatile stepper motors

10 March 2023

Magnetism is wonderful stuff.
As a way of moving things it has no peer. It has no friction, excessive heat or other unwanted effects, and is easily harnessed in the shed in the guise of stepper motors. These versatile devices have an astonishing range of rotational speeds, from zero to tens of thousands of rpm.
Thanks to the precision of digital control, they can accelerate, decelerate, turn a specific number of times or even minute fractions of a single rotation – all repeatedly and reliably.

A new global distribution agreement between element14 and Analog Devices

6 December 2022

A new global distribution agreement with Analog Devices, an international leader in the semiconductor market, has given element14 the ability to offer its customers an increased range of high-quality products for mixed signal and power management.
The new partnership with element14 will offer fast delivery of the Analog Devices range, including the latest innovative products. The broad portfolio of high-performance analogue, mixed-signal, and digital signal processing integrated circuits is suitable for many types of electronic equipment, helping design engineers to create new solutions for a variety of industries, including automotive, communications, consumer, data centres, and industrial automation.

Positive trends for gender balance in the electronics and engineering industries

30 November 2022

A new survey on global trends affecting women in the engineering/electronics industry has revealed that, although they still face major challenges, there are positive trends that highlight a continued movement towards equal treatment, regardless of gender.
This is the second survey element14 has conducted that is aimed at shedding light on women’s experiences, career paths, wider challenges, and opportunities in the engineering/electronics industry.
The results show that inequality needs to be addressed to achieve the equal treatment of all, and that women around the world remain underrepresented in the industry and continue to experience various forms of sexism and discrimination.
New questions covering discrimination, sexism, and equality were added to the 2022 survey, as these critical issues were noted as key areas in the original 2021 survey analysis.

Electronics