engineer-in-wonderland

Rooting around in the fascinating stuff at the bottom of a draw labelled 'Engineering - Junk Miscellaneous'. Delving amongst the delightful...

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Frightening e-cig chargers

I came across an electronic thing lying in a car park, which turned out to be an e-cigarette charger. 

It was a bit battered, but I thought ‘How useful, 5Vin 4.2Vout, that could charge any Li-ion cell’ (no wonder my home is full of rubbish).

Out of…

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Light stuff cuts sound

Light stuff cuts sound

I have a soft spot for honeycomb composite because an extremely skilled engineer friend of mine once used some to make the floor of a racing sidecar – most impressive.

But who would have guessed it could be used for sound-proofing – where I always thought you had to use heavy…

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Thorium nuclear reactors

Thorium reactors are rather interesting things.

Firstly, they consume thorium instead of uranium.

Secondly, they can be switched off instantly instead of having to be slowly shut down – or so I read once – which means extra safety should one get hit by a tidal wave, for example.

However, the reactions…

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A bit more industrial heritage

A bit more industrial heritage

Looking like it was about as modern as waterwheels ever got – it is an over-shot iron or steel design with a shaft driving a dual-piston pump through a wide roller chain.

Although the reservoir overflow looks like it leads off to day light, as far as I could…

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Getting somewhere with PartSim

Getting somewhere with PartSim

Having had some some issues with my first attempt at PartSim, I had a go at simulating the same circuit in LTspice.

The components are the nearest equivalents I could find quickly.

Both plots are with 10ms max step size – although I am now thinking that 0.01 step size…

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What am I doing wrong with PartSim?

What am I doing wrong with PartSim?

I am toying with ordering some LEDs and, while checking availability on Digi-Key’s site, came across another free simulator.

So I put my flasher circuit into it, and after some fiddling, this is what emerged.

Update: better results two days later

For drawing the schematic, it is easier…

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ARM laptops are back

ARM laptops are back

A long time ago I bought a Toshiba ARM netbook, and AC100, and it was very good except for some teething problems and Toshiba’s decision to stop supporting it almost as soon as it was introduced.

It had great battery life, weighed very little, great (10in) screen for its…

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Legendary loudspeakers in the conservatory

Legendary loudspeakers in the conservatory

I was invited into someone’s house over the weekend, and in the floor of the conservatory were some curious-looking loudspeakers – cylindrical in shape.

Knowing that the person who bought them, now sadly deceased, was a hi-fi buff I googled the number on the bottom ( JR149) and discovered…

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