ScrapHappy June 2018: Got a couple of minutes?

Start…

A few weeks ago, the Chez Snail toothbrush gave up the ghost. Actually, it needed its internal rechargeable battery replacing but Braun, who make the thing, don’t want you to do that. So I did. And it didn’t work. I have no idea why, I just replaced the battery.

Anyway, we bought a new, less sophisticated toothbrush which didn’t have a built-in two-minute timer, so I thought I would build one out of old bits I had lying around. Yes, these are the things I have lying around – the Snailofhappiness has all the wool and fabric.

The box contained something (I forget what) and I have had it since about 1990. The metal to make the front panel is off the cover of a hard disk drive, from about 2011. The timer circuit was one I made earlier (2005 or so) for a project that clearly never made it past the “hmm” stage.

The LEDs are from an old mobile phone system that Motorola tried to introduce in the UK (I think it was called Rabbit or something). It never caught on. I and a friend bought an old roadside box and split the electronics within, in about 1994. These LEDs were a part of my haul.

The on/off switch comes from ever further back. In 1984/5, as part of my university degree, I worked at the Rutherford Appleton Laboratories in the UK. It was like going to work in a Sci-fi film everyday – I loved it! During my time there, the old temporary hut (temporary = built in World War II) where I worked was decommissioned (i.e. pulled down) and we all mucked in to fill the skip with old junk – much of which we then fished out when no one was looking to salvage. There were pieces of computing history in that skip, and if I had had a car back then… Anyway, the switch for this scrappy project came from that skip (along with about 100 of its friends that i am still working through today).

The battery clip came from a broken toy.

The buzzer was going to be from an old ultrasonic parking radar thing but that buzzer was rubbish so I bought this one from a company as it was going bust (so bought it half price).

A bit of finagling later and it all works! Flick the switch as you start to clean your teeth, the green LED shines encouragingly, then after two minutes, on comes the red LED accompanied by a buzzer. Unfortunately, the new buzzer is, like the one it replaced, also a bit rubbish and you can’t actually hear it above the sound of the toothbrush. It isn’t a problem but I may try to improve it one day (in the very far future).

Throughout the whole build, I kept singing “Three minute hero” by The Selecter but with the words “Two Minute Timer”. Try it for yourself!

The Selecter – Two Minute Timer (well, OK, nearly)

These ScrapHappy posts are curated by Kate, who provides links to other (mostly sewing) ScrapHappy bloggers at Tall Tales from Chiconia on the fifteenth of every month. I have sneaked a non-fabric-based Scraphappy in when no one was looking!

…and Stop

oOo

 

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What’s in a Cute Mouse?

Awww…

Let’s clear this up right away – I mean a computer mouse. You didn’t think I would be opening up an actual Mus Musculus did you? Me, who passes out at the thought of blood… uh oh *falls off chair*

One large glass of wine later…

One day last week, the cute mouse for my laptop computer became non-responsive and the light went out of its not-an-eye-at-all. Now, I really do like this particular mouse: it doesn’t weigh a lot, it fits the palm of my hand perfectly and it doesn’t eat its way into my box of breakfast cereal before eating the actual cereal. The night before Christmas, it joins all other mice in not stirring but then it doesn’t indulge in this activity any other night of the year either.

I did a fast diagnosis and decided that it was probably the thin, flimsy USB cable that had probably snapped somewhere inconvenient. In fact, the wires seemed to make intermittent connections right where they disappeared into the body of the mouse.

Time to take it apart!

What most people see when they take their mouse apart…

I still experience a buzz from disassembling something for the first time. It doesn’t last that long as usually something breaks in the process and a world of sweary pain opens up, but it is there, nonetheless.

What people like me see when they take their mouse apart…

The difficult bit was removing the cable from the circuit board without melting anything important. Once that was achieved, the difficult bit was reattaching the wire having removed the bit that was broken. As suspected, the wire had indeed snapped at the grommet and, as also suspected, the grommet was an integral part of the wire. The fix here was an old-fashioned knot on the inside of the case to act as a strain relief.

Notice how the wires had been glued onto the board, making repair that much more irritating… also notice how the letters indicating the colours of each wire don’t actually match up with the colour of the wires. Genius.

 

In recovery – the patient is doing well

All back together and working well. Hopefully it will be another 3 and half years before I have to do surgery on it again!

oOo

Somebody to Cove

Replacement Front for Darth Vader’s face mask

 

For me, coving is as necessary as allowing fish to take part in the Tour de France. So, you can imagine my delight when the piece above the fireplace decided that it really wanted to visit the carpet, via the top of the fire. Sadly, the trip was too much for it and it went to pieces. About a million of them. Some of those bits are now decomposing in a raised bed. They can be squash plants in a year or two’s time.

Surprisingly, it turned out that thesnailofhappiness’s Mum had three lengths of coving in her barn. More surprisingly still, she also had a Cove Mitre which I later learnt was a really useful thing and not a piece of headgear for a pope to wear on DIY Sunday, which is probably a festival in some sects. Papa Snail had, apparently, coved (that must be the verb) their previous house and I believe that such coving was not the reason they moved out, so he must’ve been good at it.

It took me a while to figure out how to use the Cove Mitre – actually thesnailofhappiness worked it out while I swore – but cutting the coving was quick and easy. Sticking it up would have been too, if the glue had had the quality you expect of glue, you know, stickiness – but some panel pins held the coving in place while the glue thought about what it should be doing.

Eh voila! Coving up and waiting to be painted. And I thought afterwards how not only did Papa Snail make a snailofhappiness for me to love, but also gave me a Cove Mitre and two and a half metres of coving. That’s quite a debt I owe him!

All my Coving

oOo

 

Telegraph Road – Why Electric Motors made the Internet Possible (Part 2)

Where the cables emerge in a beach hut

 

 

So, your electrical signal has crawled through a thousand miles of cable under the sea, and emerged, breathless, in need of regeneration.

Once you see what was done, you can see that it was genius and, as the best ideas often are, simple. If you know when each bit (here representing a dot or a dash) is going to start, you can then make a reasonable guess as to what the original bit was. Provided there is a quite a big difference between the signal level for a dot and a dash, you should be able to regenerate the signal accurately. Regeneration hinged on knowing exactly when each bit started…

So, what could be used to reliably keep time in new electric Victorian world? A motor, that’s what. Use a clock to produce a pulse of electricity to drive a motor round and then everything could be synchronised, like the steam-powered factories that used belts to drive the machinery – only this was a pulse that drove everything in unison.

The dotted lines represent the pulses that are synchronised across the whole telegraph network, from master clocks at each relay sending/receiving station. The clocks were themselves synchronised to all the others using signals sent at the beginning of the day. There was also a speed adjustment on the interpolator to allow the speed of its motor to be tweaked to ensure absolute precision. Once you were synchronised, it was all straightforward.

1. You know when the character is supposed to start because your master clock tells you. You wait for half a turn of your motor – this puts you right in the middle of the incoming bit.
2. You then ask the question – is this signal above or below the reference (plus or minus a few microvolts to allow for noise)?
3. If it is above, you set a high voltage (usually 100 Volts) on your outgoing cable.
4. If it is below, you set a low voltage (-100 Volts).
5. Bingo! One regenerated signal now able to crawl through the next bit of wire.

This was all done using a motor and relays. If you are familiar with Terry Pratchett’s book “Going Postal”, you may recognise a distinct “Clacks” feel to this. The thing is, this was the start of the idea of long-distance near-instant communication being made real. It was also the beginning of the rise of the (electric) machines. Operators, previously required to re-key the messages were now replaced by wires and electrons. And it turns out, wires and electrons were hopeless at sports. On Ascension Island, so few engineers replaced the 30 or so operators, that team games had to be ditched in favour of singles tennis.

A new age was dawning, where the world was becoming connected, where information would be the new empire to conquer. At the heart of this revolution was, at least to begin with, the humble electric motor.

Either the author is really tall or this is a diddy telegraph pole. I’ll let you, dear Reader, decide…

 

oOo

With huge thanks to John and Ravy (sorry to have misspelt your name here!) and, indeed, everyone who helps run the Porthcurno Telegraph Museum.

Telegraph Road – Why Electric Motors made the Internet Possible (Part 1)

Ravy patiently explaining how an interpolator works

One of the things I wanted to do on my return to Cornwall this year (it seems you can’t be banned from the county for dipping a Cornish pasty in a bottle of sauvignon so I was able to go back) was to revisit the Telegraph Museum at Porthcurno and talk with the volunteers who maintain the old telegraphic equipment. Many are ex-telegraph engineers themselves so know a thing or a hundred about telegraphs.

John patiently explaining to me how a line balancer works

Imagine: it’s a bit before 1870 and, being a wealthy Victorian, you decide to connect the new-fangled telegraph-whatchamacallit to the rest of the world (or The Empire as it was known then). You find a nice quiet cove and haul the first cable, going all the way to Portugal, onto the sand. Well, OK, YOU don’t personally because you have people to do that sort of thing.

And it all worked very well, with Morse code messages being sent back and forth from America, India and, of course, Portugal. Problem was that the signal, having crawled along thousands of miles of underwater cable, was feeling a bit washed out by the time it reached anywhere, so relay stations were built along the routes, which is why Britain and other Western European countries became very interested in those tiny Caribbean islands – it wasn’t just they fancied sunny holidays at the Empire’s expense. Messages would arrive, tired and a bit worse for wear, then be retyped (re-keyed in Morse parlance) onto the next bit of cable and so on. Lots of people were needed which was fine because there were a lot of people who fancied a holiday at the expense of the Empire.

More patient explaining

Of course, if there was one thing Victorians were in love with, it was the idea of automation. If there were two things, then the other would have been sunny holidays at the expense… oh, you know the score. So, the idea of REGENERATION was born, long before Doctor Who made it a handy way of changing the actor at the end of a series.

The issue was, as with great comedy, that of timing. How could you synchronise and also understand an exhausted signal from thousand of miles away? It needed some kind of clock and rejuvenating in some way.

And that involved a motor. And another blog post…

oOo