Posts Tagged With: electronics

ScrapHappy December 2022: Power to the Pine Tree*

Come into the (bright green) Light

Come into the (bright green) Light

Back in the mists of time, well August, I converted our old fibre optic Christmas tree from a heat-generating, electricity-guzzling halogen lightbulb to a cool, electron-sipping LED, primarily to stop The Snail of Happiness shop from becoming The Snail of Toastedness, but also to save the planet (and money on our electricity bills). In the ScrapHappy post, I mentioned that I would need to find a power supply to run it since the original one, like the UK’s recent prime ministers, was unsuited to the role**.

I decided that it was easiest to find an old unused mains supply and adapt it in some way. What I needed was something that produced about 5 volts, not particularly currenty (or curranty for that matter), that is, I didn’t need many milliamps, and could then just be adapted with a new bit on the end to plug into the tree (I was betting that I wouldn’t have a supply with the correct plug on it).

I found the perfect supply – 5 volts, a few hundred milliamps. It was an old charger for a mobile ‘phone that had long since been put on a shelf waiting for me to do something creative with it***. I tested it to make sure it did what it said on the tin, well, moulded plastic casing. Hmm… it did not! It produced an LED-sizzling 8.6 volts, meaning I felt pleased I had at least tested it before attaching it to the tree.

Annoyingly, it was the only supply I could find that was vaguely what I wanted, so I made the decision to use it and attach a thing called a voltage regulator that I would build out of bits that you have lying around (well, bits I have lying around). And guess what?

Back in August 2021, I posted about taking apart some old electronics boards which happen to have a rather useful chip on them that is a simple voltage regulator – you just add a few other components et voilà! Your supply is perfect for your LED tree. And so to work…

A scrappy plug-thingy

A scrappy plug-thingy

A scrappy voltage regulator

A scrappy voltage regulator

As you can see, it required four other electronicky bits. The casing I used was from the lights I converted to candles (see here for the gory details). Could I find the correct sized plug? Well, no, but then I came across one that had arrived in an order about five years ago that, at the time, had been surplus to requirements. See? Keeping stuff for years for no apparent reason DOES prove useful… sometimes.

Circuitry just about fits in the box

Circuitry just about fits in the box

The new bit velcroed to the old bit

The new bit velcroed to the old bit

At last, The Snail of Happiness shop now has a colour-changing, cool-running tree in its window!

Spot the tree!

Spot the tree!



* Well, a fibre optic fake pine tree anyway.

** Ooh, political satire.

*** Like that’s going to happen anytime soon.

Categories: recycling, ScrapHappy, Sustainable Stuff | Tags: , , , , | 22 Comments

ScrapHappy October 2022: Someone else’s Scrap…

A relic from a bygone age - not so bygone now!

A relic from a bygone age – not so bygone now!

Now I may be wrong (I usually am, it is my default state) but I think that one can rejoice in someone else’s ScrapHappiness and, indeed, claim a little of it for one’s own. So, before anyone puts their hand up to raise an objection, here is this month’s offering which comes in the form of a kit from the National Museum of Computing (NMOC), here in the UK at the legendary Bletchley Park.

First, the scrappy bit of this – this is a kit of electronic bits and bobs that when correctly assembled, makes a thing. Technical, I know, but I’ll explain later what the thing does as that isn’t important right now. The nifty bit about this kit is that it uses a type of electronic component that is pretty much the first type of active electronic component ever devised by humans. It is a (thermionic) valve, and not the “ooh, there’s water leaking out of it” kind but the “look, it’s glowing” kind. The real scrappygoodness (that is a word, I know, I just made it up) is the valve. It’s a piece of scrap, lying around unloved and, more importantly, unbroken. Where did it come from originally? Well…

Way back in 1955, the UK decided that one television channel (BBC1, then known as the BBC Television Service) was insufficient and that another one was needed. Cue ITV, which would be transmitted on a whole new band of frequencies so high that, well, your average TV set couldn’t receive them. Genius, I know, but you have to remember that there weren’t that many TV sets in the UK at that point. I’m going to guess around 12, but there may have been more. Anyway, in order to use existing TV sets to show the new-fangled ITV, a set-top box (“Band III convertor”) was built that would let that happen. And it did.

And you won’t be surprised that most of those set-top boxes were scrapped a few years later. It would appear though, that many ended up taken apart – they had two useful valves in them and I am guessing there were lots of people who would use them to build their own electronics.

Many decades later, and NMOC have a large stock of these valves, salvaged from defunct set-top boxes (and other places too). They designed this kit to give these old valves a new lease of life, and raise much-needed funds to run the museum.

An OK Valve

An OK Valve

There is something almost alien-looking about valve tech

There is something almost alien-looking about valve tech

Finished and Working!

Finished and Working!

I built the kit – it was pretty easy and the instructions were, on the whole, very clear. I had two issues, one of which resulted in another piece of scraphappiness and the other resulted in a bit of DIY-like swearing. There seemed to be a capacitor missing in the kit so I found an old one (probably out of a light bulb) which fitted the bill. The swearing was caused by the thing not working but, on closer inspection, I had put two of the boards too close to one another and they were touching, and not in a good way.

So, does it work and what does it do? Well…

Video link to where I sound like a sci-fi villain


Many other people contribute to Kate and Gun’s wonderful ScrapHappy every month – check out what they have been up to too!


KateGun, EvaSue, Lynda,
Birthe, Turid, Susan, Cathy,  Tracy, 
Jill, Jan, Moira, Sandra, Chris, Alys,
Claire, Jean, Jon, Dawn, Jule, Gwen,
Sunny, Kjerstin, Sue L, Vera,
Nanette, Ann, Dawn 2, Carol,
Preeti, Debbierose, Nóilin, Viv and Edi


Categories: General silliness, recycling, ScrapHappy, Sustainable Stuff | Tags: , , , | 15 Comments

ScrapHappy October 2021: Exorcising a Ghost in the Machine with a Light Bulb

What lies beneath this ancient plate that no one has looked inside for nearly a million, well 40, years?

What lies beneath this ancient plate that no one has looked inside for nearly a million, well 40, years?

A while ago, the Snail bought a 1970s’ vintage Bernina sewing machine, which is way too scary for me to use but that she drives without a care in the world, not knowing that it is clearly haunted by the ghost of a, well, suffice it to say, a ghost. The other morning, just as the sun was rising*, that ghost manifested itself.

The sewing machine just started sewing. On its own. No one around.

For one such as I, who is terrified of these electric sewing machines (or crazy-electron-using-thread-knotting hell-machines as I call them), it was only after more than the usual number of tots of rum for breakfast that I was told the awful truth: this is a known fault and it really is simple to fix.

Calling the issue a “fault” is unfair. Bernina machines are built to last forever, presumably so that when they inevitably acquire the machine equivalent of a soul at some point, they can take over the Universe. Anyway, brushing away the image of a walking foot being chancellor of the exchequer for a moment, there is a capacitor (I’ll explain in a bit) in the foot pedal controller thingy** which is manufactured such that it has a lifetime of around just 30 to 40 years. Imagine that! Imagine a mobile phone built to last more than a quarter of a century! Nope, me neither (<goes off for a quiet internal monologue-type rant>).

OK, what in blogging hell is a capacitor, I hear you cry (or is that my internal monologue too?). Well, it is a thing that stores electricity for a bit and then discharges it, so it effectively smooths out ripples in the water-like flow of electricity (if electricity flowed like water. Which it doesn’t.). Here, I think it just makes the speed of the motor smoother as you use the pedal. This type of capacitor uses a layer of paper and a layer of metal to produce the desired effect. After 40 years, the paper has broken down (much as I did when I was 40), so the two ends are essentially connected and the whole thing passes electricity all the time, irrespective of where the pedal is and whether there is actually a human operator present. This machine is a whisker away from ticking that box that says “I am not a robot” and getting away with it.

Fixing the capacitor is, in theory easy, provided you have the right replacement capacitor. Now, you can buy ones specifically for such pedals OR you can use a light bulb, obvs.

As I have ranted on about before explained before (here), modern energy efficient light bulbs (the compact fluorescent and LED kinds) have some electronics in to make them work. When the light-making bit stops making light, all the electronic components are destined to be, at best, melted down, at worst, left in landfill. Whether energy efficient bulbs (CFs or LEDs) are better overall for the environment is a whole other rant for another day. For this day, such a circuit board was recovered and a suitable capacitor – right capacitance value, size and voltage rating – was rescued from a melty/landfill future to live its life in the volume***, I mean, speed pedal of a sewing machine. I bet its what that capacitor grew up wanting to do.

After 40+ years of loyal service, this capacitor has gone all gooey on us

After 40+ years of loyal service, this capacitor has gone all gooey on us

473K400? But you don't look a day over 25...

473K400? But you don’t look a day over 25…

I assumed that it would take me ages to scavenge a new component, but a bit of an old CF bulb was lying on my workbench, actually on top of the junk, er, useful things that live there. And you know what? That brown sweet-looking thing marked 473K400 was perfect – being, as it is, a 0.047 microfarad 400 volt capacitor and not a piece of gone-off strawberry chewing gum. The original capacitor was also not a piece of gone-off strawberry chewing gum but was, in fact, a 0.05 microfarad 250 volt capacitor. Happy days, if you are a nerdy electronics geek like me.

New capacitor, ready for 30 years' service

New capacitor, ready for 30 years’ service

As you can see, the new capacitor is much smaller than the old one and rated at 400 volts rather than 250, which means it should be even better! Whether it will last longer, I wouldn’t like to say. Ask me in 30 years…

Help! There's a bee using the sewing machine!

Help! There’s a bee using the sewing machine!


* Apart from the implicit plagiarism of song lyrics, the sun did not so much rise as hide behind the rain the whole day.

** Sorry, being technical again.

*** Oops, I play electric guitar and am way more used to volume pedals.



Many other people contribute to Kate and Gun’s wonderful ScrapHappy every month – check out what they have been up to too!

KateGun, EvaSue, Lynn, Lynda,
Birthe, Turid, Susan, Cathy,  Tracy, Jill,
Claire, Jan, Moira, Sandra, Chris, Alys,
Claire, Jean, Jon, Dawn, Jule,
Gwen, Bekki, Sunny, Kjerstin, Sue L,
Vera, Nanette, Ann, Dawn 2, Bear,
Carol, Preeti, Edith, Debbierose and Esther

Categories: recycling, repair, ScrapHappy, Sustainable Stuff | Tags: , , , , | 29 Comments

Mend It Monday: (It’s been) A Card Made Right

Looks like that must've hurt!

Looks like that must’ve hurt!

Some years ago, the Snail bought a new digital camera that was waterproof/shockproof/80% proof. Well, maybe not the last one but I needed three things for the list. Later came the purchase of a 16GB SD memory card, which we considered to be way bigger than we would ever need. And we were right.

In the early days, the Snail didn’t have a cable to connect the camera (via USB) to a computer to download the pictures, so would remove the card to put in a reader on her laptop. Over the years, the contacts on the card have worn away, to the point where they were drummed out of the International Contact Society for failing to live up to their essential tenet, at least inside the camera. That’s when a toothpick came to the rescue. Wedged between the card and the battery, it seemed to do the trick.

Until the other day.

The camera refused to accept that there was a card in the camera and was not going to enter into any other discussions because, deep down, the camera is, in fact, a computer.

The card itself would work in a USB card reader I had, so clearly it wasn’t completely beyond rescue.

Some frankly horrific use of a soldering iron later, and I had managed to flow some solder over the four most worn contacts whilst only melting a small chunk of the card’s body. In fact, so horrible does it look, I think the picture may need a warning notice on it.

The horror, the horror! Just, ugh, horrible. But it works!

The horror, the horror! Just, ugh, horrible. But it works!

And, in a turn up for books everywhere, it seems to work! It never needs to be removed again as we have USB cables around the place that fit, so hopefully, the other contacts won’t wear to the point of failure.

I wonder how many perfectly functional SD cards have gone to landfill because the contacts have worn through?



Categories: camera, repair, Sustainable Stuff | Tags: , , , | 15 Comments

ScrapHappy September 2020: Illuminated Words

As with many of my ScrapHappy projects, this was a really simple idea that took ages to realise! As I have already mentioned on more than one occasion, my original Generation 3 Kindle became irreparable and was replaced by a Generation 2 model (earned through the medium of cheese-making). My Kindle cover has a built-in LED reading light, one that is powered off the Kindle itself – provided you use a Generation 3 model.

But if you could attach some some batteries…

My original plan was to use my non-patented bulldog clip battery holder (see here for the gory details) but with a smaller clip and smaller batteries. It was important that the cover still close once the batteries were fitted.

After three near misses between tiny button cells and my eyes, I decide to use slightly bigger batteries and some other holder. And then it hit me – and it wasn’t a button cell.

From one of the boxes of carefully stored bits and pieces came this – the circuit that was in a leaving card no less, one that made the sound of someone crying profusely every time it was opened**. 

Leaving Card Boo Hoo

I knew hanging on to this for a decade would pay off

I just needed to cut away the bits I didn’t need, reconfigure the holders so that there were in a straight line and that would be that…


In pieces…

I wired them such that the holders didn’t obstruct the page-turn buttons, and hey presto!


Checking they fit…


And then there was… a set of functional light emitting diodes


* Plan is a grandiose word here, vague idea is more accurate.

** Clearly the one which has the sound of someone breathing a sigh of relief was sold out.

Categories: recycling, ScrapHappy, Sustainable Stuff | Tags: , , | 13 Comments

Create a free website or blog at