One Of The Largest Large Format Cameras You Will Ever Have Seen

July 31, 2021 by Jenny List 19 Comments

When fate lands a very high quality lens in front of you, what do you do with it? If you are [Tim Hamilton], the solution is obvious. Use it in a huge large-format camera.

The lens came from a newspaper magnifier made redundant by digitalisation and used as a paperweight. It’s an extremely high quality piece of optical equipment so seeing it wasted in this way was a source of distress. So after characterising it an enormous scaled-up box and bellows was constructed, and set upon a suitably substantial wheeled tripod.

Instead of a huge piece of film or some unobtainable giant electronic sensor, the image is projected onto a large screen at the rear of the camera. A modern digital camera is mounted inside the box just beneath the lens and photographs the screen, resulting in the feel of the largest of large format cameras with the convenience of a digital format. The resulting images have a special quality to them that recalls pictures from the past, and definitely makes the camera a special if slightly inconvenient device.

This may be one of the larger cameras we’ve featured, but it’s not the first that uses a similar technique.

British Big Rigs Are About To Go Green

July 31, 2021 by Jenny List 78 Comments

An increasing fact of life over the coming years will be the decarbonisation of our transport networks, for which a variety of competing solutions are being touted. Railways, trucks, cars, and planes will all be affected by this move away from fossil fuels, and while sectors such as passenger cars are making great strides towards electric drive, there remain some technical hurdles elsewhere such as with heavy road freight. To help inform the future of road transport policy in the UK then, the British government are financing a series of trials for transportation modes that don’t use internal combustion. These will include a battery-electric fleet for the National Health Service and a hydrogen-powered fleet in Scotland, as well as a trial of the same overhead-wire system previously given an outing in Germany, that will result in the electrification of a 12.4 mile section of the M180 motorway in Lincolnshire.

We’ve written about the overhead electrification project in Germany in the past and subjected it to a back-of-envelope calculation that suggested the total costs for a country such as the UK might be surprisingly affordable. The M180 is something of a backwater in the UK motorway network though, so it will be interesting to see how they approach the problem of finding real-world loads for their tests that ply such a short and isolated route. We’d expect the final picture to include all three technologies in some form, which can only be a good thing if it increases the available electric and hydrogen infrastructure. We’ll follow this story, though sadly we may not be able to blag a cab ride on the M180 in one of the trucks.

A LiPo Cell Makes A 4AA Pack For A GameBoy

July 31, 2021 by Jenny List 14 Comments

Electronic toys of yesteryear were fantastic objects of desire, but came with the fatal flaw of requiring batteries. Batteries that cost more than the average youngster’s pocket money and for which the pestered parent were usually unwilling to fork out every couple of days to support an incessant playing habit. It’s something [Sen] has addressed for the Nintendo Game Boy, and rather than cutting the device up and soldering wires, the result is a unit that neatly slots into the existing 4AA battery enclosure.

The Nintendo rechargable Game Boy pack. — Much more convenient than Nintendo’s own effort!

Electrically it’s a simple case of wiring up an Adafruit module and a pouch cell, but that’s not the essence of the job in this case. Instead a huge quantity of work and iteration has gone into CAD design to the perfect-fitting pack. It’s sure to be a boon for today’s Game Boy player, but much more than that it should be of interest to owners of far more devices that take four AA cells. Most of us probably keep a few packs of AAs for just those moments, perhaps meanwhile something like this could be a handy thing to have instead.

More traditional conversions resort to extreme measures, as with this Game Boy Color.

Developing The First ICs In Orbit

July 31, 2021 by Jenny List 19 Comments

Over six decades of integrated circuit production we’ve become used to their extreme reliability and performance for a very reasonable price. But what about those first integrated circuits from the early 1960s? Commercial integrated circuits appeared in 1961, and recently Texas Instruments published a fascinating retrospective on the development of their first few digital ICs.

TI’s original IC product on the market was the SN502, a transistor flip-flop that debuted at $450 (about $4100 today), which caught the interest of NASA engineers who asked for logic functions with a higher performance level. The response was the development of the 51 series of logic chips, whose innovation included on-chip interconnects replacing the hand interconnects of the SN502. Their RCTL logic gave enough performance and reliability for NASA to use, and in late 1963 the Explorer 18 craft carried a telemetry system using the SN510 and SN514 chips into orbit. 52 and 53 series chips quickly followed, then in 1964 the 54 series TTL chips which along with their plastic-encapsulated 74 series equivalents are still available today.

Considering that in 1961 the bleeding edge of integrated circuit logic technology was a two-transistor chip with hand interconnects, it seems scarcely conceivable that by ten years later in 1971 the art had advanced to the point at which the first commercially available microprocessors would be produced. It’s unlikely that many of us will stumble upon any of the three-figure SN1-series logic chips, but to read about them is a fascinating reminder of this pivotal moment in the history of electronics.

Header: Mister rf, CC BY-SA 4.0.

Fresh Paint Or Patina Of Ages, That’s The Antique Question

July 30, 2021 by Jenny List 46 Comments

The world of antique furniture and the world of hackers rarely coincide, and perhaps the allure of the latest tech is greater for most of us than that of a Chipendale cabinet. But there are times when there are analagous situations in both worlds, so it’s worth taking a moment to consider something.

This late-17th-century dressing box would not be of such value or interest were a restoration to strip it of its patina. Daderot, CC0.

Antique furniture has survived for hundreds of years before being owned by today’s collectors. Along the way it picks up bumps and scrapes, wear, and even the occasional repair. Valuable pieces turn up all the time, having been discovered in dusty attics, cowsheds, basements, and all sorts of places where they may have been misused in ways that might horrify those who later pay big money for them. Thus there is a whole industry of craft workers in the field of furniture restoration whose speciality lies in turning the wreck of a piece of furniture into a valuable antique for the showroom.

The parallel in our community if you hadn’t already guessed, can be found in the world of retrocomputers. They are the antiques we prize, they come to us after being abused by kids and then left to languish in a box of junk somewhere. Their capacitors are leaking, their cases may be cracked or dirty, and they often possess the signature look of old ABS mouldings, their characteristic yellowing. This is caused by the gradual release of small quantities of bromine as the fire retardant contained within the plastic degrades under UV light, and causes considerable consternation among some retrocomputing enthusiasts. Considerable effort goes into mitigating it, with the favourite technique involving so-called Retr0bright recipes that use hydrogen peroxide to bleach away the colour.

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Know Audio: Amplifiers And Distortion

July 29, 2021 by Jenny List 31 Comments

As we’ve traced our no-nonsense path through the world of Hi-Fi audio, we’ve started with the listener, understood the limitations of the human ear, and thence proceeded to the loudspeaker. We’ve learned a bit about speaker cabinets and their design, so it’s time to venture further down the chain to the amplifier that drives those speakers.

The sharp-eyed will be ready to point out that along this path also lies the speaker cables, but since we’ll be looking at interconnects at a later date we’ll be making the dubious and simplistic assumption for now that the wires between speaker and amplifier are ideal conductors that don’t have a bearing on listening quality. We’ll be looking at amplifiers in enough detail to warrant more than one piece on the subject, so today we’ll start by considering in a slightly abstract way what an amplifier does and where it can fall short in its task. We’ll be introducing probably the most important thing to consider in any audio system, namely distortion.

The job of an audio amplifier is to take an audio signal at its input and present the same signal on its output at a greater amplitude. In the case of a preamplifier it will usually be designed to work with high impedances in the order of 50 kΩ at both input and output, while in a power amplifier designed to drive speakers or headphones it will drive a much lower impedance. Commonly this will be 4 Ω or 8 Ω for loudspeakers, and 32 Ω for headphones. Continue reading “Know Audio: Amplifiers And Distortion” →

Swamp Gas Will Get You Home

July 28, 2021 by Jenny List 61 Comments

The energy to power a motorcycle has to come from somewhere, be it a power station, a solar panel, a gas station, or a hydrogen plant. There have been many ways to reduce the cost of extracting that energy over the years, but we think [Gijs Schalkx] may have hit upon one of the cheapest and simplest we’ve ever seen. It may not be free gas, but it is free swamp gas! His Uitsloot (we think that’s Dutch for “From the ditch”) motorcycle gets its power from methane generated in the sediment at the bottom of the Netherlands’ many waterways.

At its heart is a venerable Honda Cub moped, we’re guessing of the 50 cc version. On its pillion is a large clear container, inside of which is a balloon filled with gas. He doesn’t go into details in the video below the break, but we’re guessing he’s injecting the gas into the Honda’s airbox from which the engine can suck the gas/air mixture. We like his gas collector, a large inner tube with a collector funnel in its centre that floats on the water. He dons some waders and pokes the sediment with a long stick to release bubbles of methane. He then uses a long hose and a bicycle pump to inflate the balloon with the collected gas. We see him zipping around the streets of Arnhem under this unconventional power, though sadly we don’t see how far a full balloon will take him.

There’s a discussion to be had as to the environmental credentials of this project, but we think given that the naturally generated methane which would find its way into the atmosphere eventually has a greater effect on the climate than the CO2 produced by the engine, he may be onto a winner. It is however not a system that would scale to more than a few drivers poking at bogs with a stick.

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