Posts Tagged With: electronics

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

ScrapHappy May 2020: I can’t believe it’s not a battery holder!


What on earth could you make with these bits of scrap (not the coaster, I need that to put my coffee on)?

I said I would do an electronics-based ScrapHappy because, you know, why not? This is a very simple thing but will be handy to, well, me because I build things from time to time that use these little coin batteries. They need a holder since soldering direct to them is pretty dangerous and makes replacement, well, pretty dangerous too.

So, all you need is a piece of insulating material (like cardboard, thin wood, or an offcut of plain stripboard like I have used here), a piece of stiff, uninsulated wire (an offcut from a component lead is what I used, about 2cms long) and a small bulldog clip (colour optional).

Put the ends of the wire through holes 0.5cm or so apart (long enough to provide a good base for the battery to sit on) and join the ends on the other side. These form your negative connection unless you put the battery in the other way up.


Then put the clip over as shown and remove the bottom handle (? Opening oojamaflip? Thing you press to open the clip). The top flippy-opener thing is the positive connection). Easy, huh?

Eh, voila! One battery clip for any number of coin cells from one to, oh I don’t know, let’s say three (actually, as many as will fit under the clip without pinging out at an inconvenient time).


Powering two-thirds of another thing built from scraps


Here are the links for everyone who joins ScrapHappy from time to time (they may not post every time, but their blogs are still worth looking at):

KateGun, TittiHeléneEvaSue, Nanette, Lynn, Lynda,
Birthe, Turid, Susan, Cathy, Debbierose, Tracy, Jill, Claire, Jan,
Moira, SandraLindaChrisNancy, Alys, Kerry, Claire, Jean,
Joanne, Jon (me!), HayleyDawn, Gwen, Connie, Bekki, Pauline, Sue L,
Sunny and Kjerstin


Categories: ScrapHappy, Sustainable Stuff | Tags: , , | 18 Comments

Shaving the Planet


A Razor and a tool to take it apart… guess what’s going to happen!

There are many things that irritate me in life. Rather than list them all here, I would just say check out Wikipedia, that covers most of them. One thing that not only gets my goat, but then slaughters it in some satanic ritual after which it claims supernatural powers, is the way electronic devices have non-replaceable rechargeable batteries.

I’ve banged on about this before – Chez Snail’s radio is a prime example (here it is, look). I suppose the issue stems from the fact that, these days, rechargeable batteries last a long time by which point I am supposed to be a good consumer and buy a new whatever-it-is.

Yeah, like that’s going to happen…

I have had my electric razor many, many years now. It has a winter break then is eased back into service as I go from full beard (winter plumage), through a goatee thing (Spring plumage), to no beard at all (Summer plumage), Autumn, much like life, is like spring but in reverse. So, I always knew that one day the internal battery in my razor would stop working properly.

That day arrived.

I psyched myself up to have a battle to get into the thing, let alone sort out the problem. There are two screws on the back that I had to enlarge to see what kind of screws they were – those security star-shaped things, as it turned out. My trusty £1 bargain bin tool was the one to use here. After the screws were removed, the whole case came off very easily so well done Philips for making that bit easy.


Joy! Easy to get into and nothing complicated to get in the way!

The battery was soldered to the board, which I expected.

The only problem I had was prising the battery off the sticky pad it was on – quite why it was attached like this, I don’t know since the back casing was moulded around the battery anyway. Never mind…


Old Battery Out…

Thirty minutes later and the job was done. I think the last battery lasted about ten years. I should get another decade out of this one!


…New Battery In

So, have a look at taking that device apart and replacing the rechargeable battery the next time – your nearest repair cafe/geeky me-type person/teenager will probably be able to help you save the planet, one battery at a time!


Categories: recycling, repair, Sustainable Stuff | Tags: , , , | 9 Comments

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