Author: Jenny List

3275 Articles

Veteran Polaroid Camera Lives Again, With Film Conversion

January 3, 2023 by 8 Comments

Browsing the thrift stores will net an amazing array of old cameras for dirt cheap prices, meaning that a film enthusiast can have plenty of fun without wasting money they could spend on the film itself. Unfortunately many of the more interesting cameras are those which use film long out of production, leaving the photographer with a need to improvise using a more modern film that’s still in production.

[Nicholas Morganti] has just such a camera, a Polaroid Big Shot, a 1970s instant camera designed for portrait work, for which the Polaroid 100 film packs are sadly a distant memory. Leave it on the shelf? Not likely, he’s adapted it to work with Fuji Instax 210, a readily available and cheap instant film.

Polaroid 100 and Instax 210 are almost the same size, but are not close enough for a direct fit. An Instax cartridge can be persuaded to fit into the Big Shot, but it’s a tight fit that puts strain on the aged Polaroid hinges. Even then the Polaroid rollers and photo ejection system are very different from those in the Fuji, so it involved a workflow in which the cartridge had to be unloaded in a darkroom between shots and processed through a real Fuji camera for the final picture.

His eventual solution takes a less camera-straining tack, still requiring a darkroom but taking an individual unexposed frame from an Instax pack and placing it in the Big Shot on an adapter plate. The result is a usable if a little cumbersome workflow for vintage Polaroid pictures, something plenty of instant photography enthusiasts will be thankful for. If you’re one of them, you might like to read our look at the process.

A Single Ended Vacuum Tube Amplifier With A Modern Twist

January 3, 2023 by 40 Comments

Despite the oldest solid state audio circuitry now qualifying for a pension and a bus pass where this is being written, the thermionic tube retains a foothold in the world of audio — cherished by enthusiasts for the warm sound it is claimed to impart. For  the electronics enthusiast a tube audio amplifier makes for an interesting and unusual project, and for that reason it’s one tackled by many. [Keri Szafir] is no exception, and she’s produced a stereo tube amp with a few modern features.

Electrically it’s a relatively conventional single-ended design using a double triode and a power pentode for each channel. It follows a so-called ultra-linear circuit, with a tap on the output transformer feeding one of the pentode’s grids. The modern features come via a switched Bluetooth input and a motorized volume control, something that would have never been found on such an amp when they were the cutting edge.

We have to admit a soft spot for this type of amp, and we particularly like this one for its very period construction style using cable lacing to keep the wiring under control. We more often see these amps using the cheaper integrated triode-pentode tubes which makes them especially easy to build, so the separate preamp is a little different. We’re not sure we’d have spent extra on the fancy E88cc tubes though. Continue reading “A Single Ended Vacuum Tube Amplifier With A Modern Twist” →

What’s New, From 1927

January 2, 2023 by 13 Comments

Here we are at the start of the new year, which for the Internet Archive means a note about what has just entered the public domain. 1927’s finest previously copyrighted materials are now up for grabs in the public domain, which means there’s a treasure trove of films, books, and music to freely copy and remix.

Their article highlights a few notable pieces of 1927’s popular culture , of which we suggest you should definitely take note of Fritz Lang’s Metropolis if you have any interest in sci-fi, but for Hackaday readers there’s not much else in the article itself relating to technology. Delving into the archive for 1927 is still a fascinating pastime though, because beyond the interest of seeing what’s now free it led onto what was the state of technology in the 1920s. And here we find ourselves as much navigating the English language as we do the library itself, because so much of what we do uses vocabulary from the decades since. Continue reading “What’s New, From 1927” →

A Bicycle Trailer Fit For Heavy Haulage

January 2, 2023 by 8 Comments

One of the problems of being a cyclist is that a bicycle just isn’t designed to carry much more than a human. You can get panniers and hang shopping bags from the handlebars, but sooner or later there’s a load which just doesn’t fit. At that point there’s only one way forward that involves staying on two wheels: find a bike trailer. If you fancy building one yourself, then there’s La Charette (French language, Google Translate link), an open-source three-wheeler design from France.

Construction is a sturdy welded box section tube spaceframe, with the single wheel at the front providing steering, and a towing bar attached to the seat post of the bicycle. Along with the impressive load capacity comes the problem of towing it, and for the cyclist with less-than-superhuman strength there’s the option of an electrically-driven front wheel. Stopping the whole thing is an essential feature with loads this size, and to that end there’s an inertial braking system operated by the force on the towing bar.

All in all it appears to be a useful trailer, albeit on the large side for storage when not being used. It’s certainly one of the larger bike trailers we’ve seen, though not perhaps the most stylish.

Thanks [Jeff] for the tip!

Get To Know Touch With This Dev Board

December 31, 2022 by 5 Comments

In the catalogue of the Chinese parts supplier LCSC can be found many parts not available from American or European suppliers, and thus anyone who wants to evaluate them can find themselves at a disadvantage. [Sleepy Pony Labs] had just such a part catch their eye, the Sam&Wing AI08 8 channel capacitive touch controller. How to evaluate a chip with little information? Design a dev board, of course!

The chip tested is part of a family all providing similar functionality, but with a variety of interface options. The part tested has eight touch inputs and a BCD output. Said output is used to feed a 74 series decoder chip and drive some LEDs. The touch pads were designed with reference to a Microchip application note which incidentally makes for fascinating reading on the subject as it covers far more than just simple touch buttons.

Whether or not you’ll need this touch chip is a matter for your own designs, however, what this project demonstrates is that with the ready availability of cheap custom PCBs and unexpected parts it’s not beyond reason to create boards just for evaluation purposes.

Perhaps the subject of a previous Hackaday piece would have found this board useful.

If You Can’t See A Solar Panel, That Doesn’t Mean It’s Not There

December 31, 2022 by 45 Comments

In the shift away from fossil fuel energy sources, there has been a huge expansion in solar power. We’ve seen solar thermal plants in the desert and photovoltaic panel farms covering huge areas of land, but perhaps the most potential comes from placing the panels on rooftops. In some parts of the world this is encouraged through a system of subsidies, as is the case in Italy. But what if your building is part of a protected world heritage site such as the Roman city of Pompeii? The answer comes in the form of traditional roof tiles that hide their photovoltaic elements under a polymer skin that looks for all the world like a traditional Roman pan tile. As is so often the case with such products, the manufacturer’s description page is cagey about the details in the name of protecting their invention. What they do tell us is that the tile uses conventional solar cells mounted underneath the polymer layer, which is described as “opaque at the sight but translucent to sun rays“. This sounds like an inherent contradiction, so naturally, we’re intrigued as to how it works. Continue reading “If You Can’t See A Solar Panel, That Doesn’t Mean It’s Not There” →

Audio Old And New Meet In Perfect Harmony

December 30, 2022 by 20 Comments

There’s an uneasy meeting in the world of audio between digital and analogue. Traditional analogue audio reached a level of very high quality, but as old-style media-based audio sources have fallen out of favor there’s a need to replace them with ones that reflect a new digital audio world. To do this there are several options involving all-in-one Hi-Fi separates at a hefty price, a cheaper range of dongles and boxes for each digital input, or to do what [Keri Szafir] has done and build that all-in-one box for yourself.

The result is a 1U 19″ rack unit that contains an Orange Pi for connectivity and streaming, a hard drive to give it audio NAS capability, plus power switching circuitry to bring all the older equipment under automation. Good quality audio is dealt with by using a Behringer USB audio card, on which in a demonstration of how even some digital audio is now becoming outdated, she ignores the TOSlink connector.

The rear panel has all the connectors for power, USB, network, and audio laid out, while the front has an array of status lights and switches. We particularly like the hand-written lettering, which complements this as a homebrew unit. It certainly makes the Bluetooth dongle dangling at the back of our amplifier seem strangely inadequate.

If audio is your thing, we had a look at some fundamentals of digital audio as part of our Know Audio series.