CCFL Scanner Bulb Makes A Cool Desk Lamp

August 31, 2024 by Alexander Rowsell 12 Comments

The bulbs inside scanners (before transitioning to LED, anyway) were cold cathode fluorescent tubes that emit a fairly wide bandwidth of light. They were purpose-built to produce a very specific type and shape of light, but [Julius Curt] has taken this in a new, upcycled direction. Instead of just producing light, the light itself is also part of the aesthetic. A very cool 3D printed case houses the bulb and power supply and smartly hides the connecting wires to achieve a very clean look.

Part of the design involves adding a DC-DC converter before the lamp driver, allowing fading of the light. This isn’t anything new in lamps, but [Julius] noticed an interesting effect when dimming the vertically oriented lamp: as the power was reduced, the column of light would start to extinguish from one end, leading to an elongated teardrop-shaped light source.

This leads to a very interesting look, and the neat case design leads to an extremely unique lamp! The emitted light’s color temperature seems to vary a bit as the voltage drops, going from what appears to be a pretty cold white to a slightly warmer tone.

The design process is detailed on the project page, with a quick look at the CAD design process for the case. A neat touch was using a greeble (part of a coffee grinder) to add some different textures and break up the plastic-only look. That’s one we’ll have to note in our design books!

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Your Name In Landsat

August 31, 2024 by Jenny List 8 Comments

We’re guessing most readers can cite things from their youth which gave them an interest in technology, and spurred on something which became a career or had a profound impact on their life. Public engagement activities for technology or science have a crucial role in bringing forth the next generations of curious people into those fields, and along the way they can provide some fun for grown-ups too.

A case in point is from NASA’s Landsat engagement team, Your Name In Landsat. Type in a text string, and it will spell it out in Earth features seen by the imaging satellites, that resemble letters. Endless fun can be had by all, as the random geology flashes by.

The text entry form with a pop-up warning only A to Z are accepted. — No text emojis, boo hiss!

In itself, though fun, it’s not quite a hack. But behind the kids toy we’re curious as to how the images were identified, and mildly sad that the NASA PR people haven’t seen fit to tell us. We’re guessing that over the many decades of earth images there exists a significant knowledge base of Earth features with meaningful or just amusing shapes that will have been gathered by fun-loving engineers, and it’s possible that this is what informed this feature. But we’d also be curious to know whether they used an image classification algorithm instead. There must be a NASA employee or two who reads Hackaday and could ask around — let us know in the comments.

Meanwhile, if LANDSAT interests you, it’s possible to pull out of the air for free.

The Trashiest Of Mains Inverters

August 31, 2024 by Jenny List 21 Comments

Switch-mode technology has made inverters which take a low DC voltage and turn it into a usable mains voltage within the reach of everybody. But still, there might be moments when a mains supply is needed and you’re not lucky enough to have AliExpress at your fingertips, and for that, here’s [Rulof] with a mains inverter that is simultaneously awful and awesome. He’s made a rotary converter, from trash and off the shelf parts.

While a switch-mode converter operates using PWM at many times the output frequency for efficiency, we’re guessing that most readers will be familiar enough with how AC works to see how a low frequency converter turns DC into AC. A set of switches repeatedly flip the polarity, and the resulting square wave is fed into a transformer to step up to the final voltage. The switches can be mechanical as with old-style converters that used vibrating reeds or rotary armatures, or they can be electronic using power transistors. In this case they are a set of microswitches actuated by a set of cams on a shaft driven by a small motor, and the transformer comes from a surplus UPS.

We’re guessing that the frequency will be only a few Hz and the microswitches will suffer from switching such an inductive load, but as you can see in the video below the break it does light a mains bulb, and we’re guessing it would be enough to activate most wall-wart switching power supplies. We’re not so sure though about his use of the IEC sockets from the UPS to carry 12 volts, as the current may be a little much for them.

Meanwhile if you thirst for more of this kind of thing, we have you covered.

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Left: the ATtinyBoy and cartridges inside a custom case. Right: ATTinyBoy under the hood.

2024 Tiny Games Contest: ATtinyBoy Does It With Tiny Cartridges

August 31, 2024 by Kristina Panos 3 Comments

What is it about tangible media? There’s just something neat about having an individual thing that represents each game, each album, each whatever. Sure, you can have a little console with a thousand games loaded on it, but what’s the fun in that?

Enter the ATtinyBoy. [Bram]’s entry into the Tiny Games Contest is based on the ATtiny85, and the whole thing is smaller than a credit card. In fact, each little game cartridge contains its own ATtiny85, with the pins broken out into headers.

That is, although the schematic is based on [Billy Cheung]’s gametiny, which uses an ATtiny85 as the brain, ATtinyBoy’s brain is divided among each of the games.

This certainly checks a lot of boxes when it comes to contest rules and requirements, and it’s just awesome besides. We particularly like the custom box that holds ATtinyBoy and all his distributed knowledge. If you want to make one of your own, the schematic, code, and STLs are all available over on IO.

A milling machine with an attached pantograph following the various intricate patterns of a spirograph on the bench next to it. The spirograph is a series of acrylic gears and brass connecting bars mounted on a wooden base.

Taking A Spirograph Mill For A Spin

August 31, 2024 by Navarre Bartz 3 Comments

Spirographs can make some pretty groovy designs on paper, but what if you want to take it a step further? [Uri Tuchman] has used the pantograph on his milling machine to duplicate the effect in harder materials.

[Tuchman] starts with a quick proof-of-concept using an actual plastic Spirograph toy to make sure it isn’t a totally unworkable idea. Unsurprisingly, the plastic is too flexible to give a highly detailed result on the MDF test piece, so he laser cut an acrylic version as the next prototype. This provided much better stiffness, but he needed to adjust gear ratios and ergonomics to make the device more usable.

The final iteration uses a combination of laser cut acrylic and machined brass components to increase rigidity where needed. A hand-turned knob for the crank adds a classy touch, as does the “Spiromatic 2000” brass plate affixed to the wooden base of the mechanism.

This isn’t the first spirograph-related project we’ve seen. How about one made of LEGO Mindstorms, another using Arduino, or one that makes these patterns on your oscilloscope?

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Make Your Own Point Contact Transistor

August 31, 2024 by Jenny List 21 Comments

Beyond the power variant, it sometimes seems as though we rarely encounter a discrete transistor these days, such has been the advance of integrated electronics. But they have a rich history, going back through the silicon era to germanium junction transistors, and thence to the original devices. if you’ve ever looked at the symbol for a transistor and wondered what it represents, it’s a picture of those earliest transistors, which were point contact devices. A piece of germanium as the base had two metal electrodes touching it as the emitter or collector, and as [Marcin Marciniak] shows us, you can make one yourself (Polish language, Google Translate link).

These home made transistors sacrifice a point contact diode to get the small chip of germanium, and form the other two electrodes with metal foil glued to paper. Given that germanium point contact diodes are themselves a rarity these days we’re guessing that some of you will be wincing at that. The video below is in Polish so you’ll have to enable YouTube’s translation if you’re an Anglophone — but we understand that the contact has to be made by passing a current through it, and is then secured with a drop of beeswax.

A slight surprise comes in how point contact transistors are used, unlike today’s devices their gain in common emitter mode was so poor that they took instead a common base configuration. There’s a picture of a project using three of them, a very period radio receiver with bulky transformers between all stages.

If you’re interested in more tales of home made early transistors, read our feature on Rufus Turner.

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Universal Power Bank Customized To Your Liking

August 31, 2024 by Bryan Cockfield 10 Comments

One of the most troubling trends of almost every modern consumer product that uses electricity is that the software that controls the product is likely to be proprietary and closed-source, which could be doing (or not doing) any number of things that its owner has no control over. Whether it’s a computer, kitchen appliance, or even a device that handles the electricity directly, it’s fairly rare to find something with software that’s open and customizable. That’s why [Traditional-Code9728] is working on a power bank with an open-source firmware.

From a hardware perspective the power bank is fairly open as well, with a number of options for connecting this device to anything else that might need power. It sports a bidirectional USB-C port as well as a DC barrel plug, either of which can either charge other devices or receive energy to charge its own battery. These ports can also accept energy from a solar panel and have MPPT built in. There’s also dual USB-A ports which can provide anywhere from five to 12 volts at 25 watts, and a color screen which shows the current status of the device.

While this is a prototype device, it’s still actively being worked on. Some future planned upgrades to the power bank include a slimmer design, charge limiting features to improve battery life, and more fine-tuned control of the output voltage and current on the USB-C port. With all of the software being open-source, as well as the circuit diagram and 3D printing files, it could find itself in plenty of applications as well. This power bank also stays under the energy limits for flying on most commercial airlines as well, but if you don’t plan on taking your power bank on an airplane then you might want to try out this 2000-watt monster instead.