DIY capacitor leakage tester nestled among neighbours all mounted underneath a shelf

DIY Capacitor Leakage Tester With A Professional Finish

January 22, 2023 by 7 Comments

[Manuel Caldeira] has built a nice electronics work area that would be the envy of many, complete with an under-shelf rail of custom-built instruments that are specific to the needs of areas of electronics that [Manuel] is involved with. The highlighted project here is a capacitor leakage tester, which is very handy for sorting through piles of old parts looking for anything still within spec, or just verifying a part on a board is the culprit you suspect it is.

The thing is, certain types of capacitors have a limited life both in operation and in storage. Usually, we’re talking about electrolytics here, where the electrolyte solution can leak out or dry out, but also the passive oxide layer on the anode plate can deteriorate if the device is left unpowered for long periods — the oxide disintegrates, and the capacitor will start to leak current. Eventually, the breakdown can be bad enough for the capacitor to conduct so well that it overheats and the result can be a surprisingly violent experience. So, if you deal with capacitors a lot, especially electrolytics, then a leakage tester is a very good instrument to own.

We like [Manuel]’s construction method here, with custom PCBs nestled inside a simple bent aluminium enclosure. No need for a top or sides, as these, are intended to bolt underneath a shelf, and butt up against their neighbor. The front panel graphics are done in a simple but very effective manner, using printable sticker sheets, with a clear adhesive over-sheet. They certainly have a professional finish, and this is definitely a construction method worth considering.

For those a little unfamiliar with this important component, why not leap into some theory with this handy dive into the simple parallel plate capacitor? Next, may we suggest a little overview of the different capacitor types and how to best make use of them?

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Wii Turned Expansion Card For Broadcast Monitor

January 22, 2023 by 9 Comments

For the proper retro gaming aesthetic, plenty of gamers look to old CRT displays. Older games can look better on these displays because the original programmers took their visual characteristics into account. Finding a CRT from the 90s or early 2000s is one option, but an even better option is a broadcast video monitor (BVM) which were extremely high quality CRTs with some other features, like the ability to install a Wii straight to an expansion port on the monitor itself (Nitter).

These monitors were, as their name implies, made for broadcast TV productions. As such, they don’t have the typical video connections that might be found on a consumer unit. Instead, they used modular cards to interface with the monitor. Thanks to an open design for cards made for Sony monitors, [ShankMods] was able to make one for the Wii by “trimming” away the unnecessary parts of the console’s PCB and mapping its video and audio outputs to the slot connector.

While the Wii might not be everyone’s idea of retro, it was still a console that came out when plenty of people still had CRTs as their primary home television. It isn’t as necessary to have a CRT for a Wii as some of the older consoles, but it was very easily adaptable to this single-board design. If you don’t have a CRT and still want the CRT feel, there are ways of retrofitting a more modern display to get this effect, though.

Thanks to [Jonas] for the tip!

An Unexpected Amiga Network Interface

January 21, 2023 by 31 Comments

The retrocomputer enthusiast has increasingly to grapple with not only runaway computer prices but the astronomical cost of vintage peripherals. A welcome solution in some cases comes from the Raspberry Pi, which has proved itself fast enough to emulate those add-ons for a lot less outlay. A good one comes from [Niklas Ekström], who’s made a Pi-based network adapter for the Commodore Amiga 1200. Better still it doesn’t hog the main expansion port or the PCMCIA slot, instead it sits on the 1200’s rarely-used real-time-clock port. Software wise it uses an updated version of his earlier project for the Amiga 500. It provides access to the Pi command prompt, as well as a SANA driver and a mounted filesystem.

While many of us view the Amiga from 2023 as a retro gaming platform, for those of us who used it at the time it was a desktop productivity machine on a more affordable budget than the Macintosh. At the time the thought of having a UNIX-like operating system running on a super-powerful co-processor in your Amiga would have been beyond our wildest dreams, but whether it provides enough now to make a 1992 machine compete on the desktop is debatable. Who wants to run Firefox from the Pi in an X server on the Amiga?

An illustration of a key sitting on an ID card. The key is light grey and the ID card is a darker grey gradient. The ID card says ID-1 Card 85.60 by 53.98 mm

All Your Keys Are Belong To KeyDecoder

January 21, 2023 by 56 Comments

Physical security is often considered simpler than digital security since safes are heavy and physical keys take more effort to duplicate than those of the digital persuasion. [Maxime Beasse and Quentin Clement] have developed a smartphone app that can duplicate a key from a photo making key copying much easier.

KeyDecoder is an open source Android app that can generate all the necessary bitting info to duplicate a key from just an image. Luckily for the paranoid among us, the image must be taken with the key laying flat without a keyring on an ISO/CEI 7810 ID-1 ID or credit card. A passerby can’t just snap a photo of your keys across the room and go liberate your home furnishings, but it still would be wise to keep a closer eye on your keys now that this particular cat hack is out of the bag.

The project’s GitHub page is awash in warnings that this tool is designed solely for “pentesters and security enthusiasts” to warn their friends and clients about the dangers of leaving their keys exposed. After learning about this tool, we wouldn’t be surprised if some in the audience start rethinking how they carry and store their physical keys from now on.

If you want to see some more hacks to duplicate keys, checkout Copying High Security Keys With OpenSCAD And Light and Methods Of Copying High Security Keys.

Floppy Photog: Making An IR Filter From A 3.5″ Disk

January 21, 2023 by 15 Comments

Sony used to sell digital cameras that recorded on actual floppy disks. We’ve come a long way, but [Mathieu] put a floppy in a digital camera recently for an entirely different reason. First, though, he had to modify the camera to work on the full spectrum, something he covered in an earlier video. You can see both videos, below.

As you might expect, he didn’t actually put an entire floppy inside the camera. He used the internal disk portion as an infrared filter to obtain some striking photos. In all honestly, the results were not as nice as what you get from a very expensive professional filter. But the pictures looked great and the difference was not as much as you’d expect compared to the cost difference.

The real work, though, is converting the camera to full spectrum as seen in the second video. A normal camera has an IR filter to prevent the sensor from seeing IR light. This prevents the image sensor from capturing things your eyes don’t see. The modification replaces the filter with a clear filter.

We’ve covered this kind of conversion before. You can even do it with a Raspberry Pi, if you like.

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open hardware textile spinning machine constructed from aluminium extrusions, arduino electronics and 3D printed parts

An Open Hardware Automatic Spinning Machine

January 21, 2023 by 6 Comments

The team at the Berlin-based Studio HILO has been working on ideas and tools around developing a more open approach to small-scale textile production environments. Leveraging open-source platforms and tools, the team has come up with a simple open hardware spinning machine that can be used for interactive yarn production, right on the desktop. The frame is built with 3030 profile aluminium extrusions, with a handful of 3D printed, and a smidge of laser cut parts. Motion is thanks to, you guessed it, NEMA 17 stepper motors and the once ubiquitous Arduino Mega 2560 plus RAMPS 1.4 combination that many people will be very familiar with.

The project really shines on the documentation side of things, with the project GitLab positively dripping with well-organised information. One minor niggle is that you’ll need access to a polyjet or very accurate multi-material 3D printer to run off the drive wheel and the associated trailing wheel. We’re sure there’s a simple enough way to do it without those tools, for those sufficiently motivated.

We liked the use of Arduino for the firmware, keeping things simple, and in the same vein, Processing for the user interface. That makes sending values from the on-screen slider controls over the USB a piece of cake. Processing doesn’t seem to pop up on these pages too often, which is a shame as it’s a great tool to have at one’s disposal. On the subject of the user interface, it looks like for now only basic parameters can be tweaked on the fly, with some more subtle parameters needing fixing at firmware compilation time. With a bit more time, we’re sure the project will flesh out a bit more, and that area will be improved.

Of course, if you only have raw fibers, that are not appropriately aligned, you need a carder, like this one maybe?

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Robot Collects Ping Pong Balls For You

January 21, 2023 by 9 Comments

If you’ve ever played ping pong, table tennis, or beer pong, you know that it’s a struggle to hang on to the balls. [MaximeMonsieur] has designed a robot to handle picking them up so you don’t have to.

The robot is specifically designed to pick up ultra-light ping pong balls. To that end, it has a large spinning paddle that simply wafts the balls into its collector basket at the rear. The robot gets around with a simple two-motor drive system, relying on skid-steering with a castor wheel at the rear. An Arduino Uno runs the show, and navigates the robot around with the aid of ultrasonic sensors to avoid crashing into walls.

Overall, the robot shows the benefits of designing for a specific purpose. Such a design would likely be far less successful with other types of heavier balls, but for ping pong balls, the spinning paddle collector works great. We can imagine the robot being put to good use between sets to pick up all the lost balls around a table tennis court.

We’ve seen other ball collecting robots before, too.

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