Day: July 22, 2025

USB-C-ing All The Things

July 22, 2025 by No comments

Wall warts. Plug mounted power supplies that turn mains voltage into low voltage DC on a barrel jack to power a piece of equipment. We’ve all got a load of them for our various devices, most of us to the extent that it becomes annoying. [Mikeselectricstuff] has the solution, in the shape of a USB-C PD power supply designed to replace a barrel jack socket on a PCB.

The video below provides a comprehensive introduction to the topic before diving into the design. The chip in question is the CH224K, and he goes into detail on ordering the boards for yourself. As the design files are freely available, we wouldn’t be surprised if they start turning up from the usual suppliers before too long.

We like this project and we can see that it would be useful, after all it’s easy to end up in wall wart hell. We’ve remarked before that USB-C PD is a new technology done right, and this is the perfect demonstration of its potential.

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Power Grid Stability: From Generators To Reactive Power

July 22, 2025 by 8 Comments

It hasn’t been that long since humans figured out how to create power grids that integrated multiple generators and consumers. Ever since AC won the battle of the currents, grid operators have had to deal with the issues that come with using AC instead of the far less complex DC. Instead of simply targeting a constant voltage, generators have to synchronize with the frequency of the alternating current as it cycles between positive and negative current many times per second.

Complicating matters further, the transmission lines between generators and consumers, along with any kind of transmission equipment on the lines, add their own inductive, capacitive, and resistive properties to the system before the effects of consumers are even tallied up. The result of this are phase shifts between voltage and current that have to be managed by controlling the reactive power, lest frequency oscillations and voltage swings result in a complete grid blackout.

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A variety of red and black glass objects are shown on a white background. In the foreground, there are two black spiral-patterned earrings. To the left is a red and black shape with three points on the top. On the right, a deformed glass sheet is shown bent over concentric red and black glass rings. In the center top is a red glass vase with a roughly-textured exterior.

Paste Extrusion For 3D Printing Glass And Eggshells

July 22, 2025 by 4 Comments

In contrast to the success of their molten-plastic cousins, paste extrusion 3D printers have never really attained much popularity. This is shame because, as the [Hand and Machine] research group at the University of New Mexico demonstrate, you can use them to print with some really interesting materials, including glass and eggshell (links to research papers, with presentations in the supplemental materials).

To print with glass, the researchers created a clay-like paste out of glass frit, methyl cellulose and xanthan gum as shear-thinning binders, and water. They used a vacuum chamber to remove bubbles, then extruded the paste from a clay 3D printer. After letting the resulting parts dry, they fired them in a kiln at approximately 750 ℃ to burn away the binder and sinter the frit. This introduced some shrinkage, but it was controllable enough to at least make decorative parts, and it might be predictable enough to make functional parts after some post-processing. Path generation for the printer was an interesting problem; the printer couldn’t start and stop extrusion quickly, so [Hand and Machine] developed a custom slicer to generate tool paths that minimize material leakage. To avoid glass walls collapsing during firing, they also wrote another slicer to maintain constant wall thicknesses.

The process for printing with eggshell was similar: the researchers ground eggshells into a powder, mixed this with water, methyl cellulose and xanthan gum, and printed with the resulting paste. After drying, the parts didn’t need any additional processing. The major advantage of these parts is their biodegradability, as the researchers demonstrated by printing a biodegradable pot for plants. To be honest, we don’t think that this will be as useful an innovation for hackers as the glass could be, but it does demonstrate the abilities of paste extrusion.

The same team has previously used a paste printer to 3D print in metal. If you don’t have a paste printer, it’s also possible to print glass using a laser cutter, or you could always make your own paste extruder.

Floating Buoy Measures Ocean Conditions

July 22, 2025 by 7 Comments

Out on Maui, [rabbitcreek] desired to keep track of local ocean conditions. The easiest way to do that was by having something out there in the water to measure them. Thus, they created a floating ocean sensor that could report back on what’s going on in the water.

The build uses a Xiao ESP32-S3 as the brains of the operation. It’s paired with a Wio-SX1262 radio kit, which sends LoRa signals over longer distances than is practical with the ESP32’s onboard WiFi and Bluetooth connections. The microcontroller is hooked up with a one-wire temperature sensor, a DF Robot turbidity sensor, and an MPU6050 gyroscope and accelerometer, which allow it to measure the water’s condition and the motion of the waves. The whole sensor package is wrapped up inside a 3D printed housing, with the rest of the electronics in a waterproof Pelican case.

It’s a neat project that combines a bunch of off-the-shelf components to do something useful. [rabbitcreek] notes that the data would be even more useful with a grid of such sensors all contributing to a larger dataset for further analysis. We’ve seen similar citizen science projects executed nicely before, too. If you’ve been doing your own ocean science, don’t hesitate to let us know what you’re up to on the tipsline!