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Alun Jones (pengfold)
745 followers -
It's me, innit.
It's me, innit.

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With a bit of help from Sam & Tom Industries (https://twitter.com/samtomindustrys) I've got my Wimshurst machine working again. Nice fat sparkiness and a smell of ozone.

3D printed: the black insulating handles on the electrodes.

Laser cut: new discs and a template to cut the copper tape (thanks, +Sam Nicholls and +Tom Blanchard).
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23/03/2017
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Today's topic was "Timepieces", for which I hacksawed the top off a quartz crystal (it's in this pic, near top right). I thought I'd post a picture of a few more crystals in their tins, with a pound coin for scale.

The small cylindrical ones (e.g. just above the pound) are the type that's found in digital clocks/watches. They're cut to resonate at 32,768 Hz (ticks per second). In binary, 32,768 is 1000000000000000, which is a nice round number for computing with. If you have a 15 digit (bit) binary counter counting the ticks, every time it rolls over to 000000000000000, another second has gone by.
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When +Johnny Wills came up with the subject of "Timepieces" for #joinindaily this morning, I decided fairly quickly what I'd take a picture of. But it had to wait until I got home and had a hacksaw to hand!

You've probably all heard of quartz watches and clocks. You've possibly heard that these are driven by a quartz crystal inside. A suitably shaped crystal will resonate at a specific, stable frequency when power is applied to it. By counting the pulses it generates at this frequency you can measure time very accurately.

You're probably within a few inches of several quartz crystal timepieces right now - inside your computer/phone/tablet/screen/watch/clock/... Billions are made each year.

Quartz crystals are usually housed inside a metal tin to keep the delicate crystal safe. I found an old one in my electronics junk box and hacked the top off the tin for a look. This is the first time I've ever seen what's inside!

For info, the legs on this one are about 0.5" (12.7mm) apart. This is a very large example, probably 50 years old.

https://en.wikipedia.org/wiki/Crystal_oscillator
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Heh
Brilliant. I've often wondered what a self-driving car will do when it encounters what engineers call an "edge case" that its developers hadn't thought of.

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Today's #joinindaily topic from +Johnny Wills is "Mist and fog".

Here's a 15 second exposure looking across Lake Vyrnwy from the hotel on a misty evening in February 2010.

This stretched the capabilities of my camera at the time, so it's a bit of a noisy picture, unfortunately.
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Of course, the concrete boat at Portmeirion would have been a good entry for today's subject of "Ships and Large Boats". Possibly the heaviest boat for its size.
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+Johnny Wills wants "Ships and large boats (the bigger the better)" for today's #joinindaily.

Here's the Fishguard/Rosslare trimaran ferry coming into Fishguard in August 2011.

Edit: Bah, I didn't notice "the bigger the better" until after posting. I've got a few pictures of much bigger ships. Still this one isn't exactly tiny.
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Today's #joinindaily topic from +Johnny Wills is "At least 80% green". Here's a malachite table we saw at Sudbury Hall in July 2015.
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+Johnny Wills chose "Your last image of winter" for his #joinindaily topic today. Thinking how I could be obtuse, I decided to look for the official date of the end of winter. Which, I guess, was Johnny's point. According to Google, winter ends in the Northern hemisphere tomorrow.

Anyway, going back, I discovered that on 20th March 2015, the last day of winter that year, I was helping out with the University's outreach activities for a partial solar eclipse. And this was, therefore, my last image of winter for 2015.
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Today +Johnny Wills​​ has chosen "Woods or Forests" for #joinindaily. Here's a view on the Hafod estate near home.

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