Kritik sah

Sometimes a hacker has a specific sort of problem, and uses the tools they have to solve it in a way that just might be helpful to someone else. That’s the case with [Matvey Kukuy]’s Coffee Steam Dryer (V2) , which performs the very specific job of safely swallowing up expelled steam and water from an espresso machine’s steam wand. Steam purges into the top inlet and passes through expansion chambers, dragging cool air along with it, until it exits safely. Steam wands are used to froth milk into a velvety texture, and some machines require purging the wand before using it for best results. Where does the resulting jet of steam and spatter of superhot water droplets go? Not the machine’s problem. That’s for the user to deal with, and [Matvey] decided to address it by designing and 3D printing a tool. The pipe-like object works by having steam jet into the open top (printed in ABS or ASA for heat resistance) where the device redirects the hot gas and captu...

After previously adopting a big Sony Trinitron CRT TV that had been trying to hitch a ride along the side of a road in Italy for at least six years, [Happychoice] didn’t give up on trying to fix it, with the second part showing the TV being more or less fully fixed up . In the first part of this mini-series, the TV had been salvaged and had most of the dirt as well as local flora and fauna evicted before an attempt was made to fix it. Unfortunately despite the insides looking remarkably clean and intact considering its use as a road-side ornament, that video ended with the controller refusing to power up due to issues with the power supply. In this sequel we get to see what six years of weather exposure means in terms of what components to replace in a CRT TV like this. Unsurprisingly this means mostly replacing most of the capacitors, at least on the power supply board, as well as the neck board for the actual CRT. A couple of MOSFETs also tested open, so they were replaced to...

The site of the Chornobyl Nuclear Power Plant (ChNPP) remains a unique location, as what’s left of the No. 4 reactor is the only place in the world where you can find significant amounts of what is called corium. An amalgamation of nuclear fuel, fuel rod cladding and whatever materials like concrete that the molten mass came into contact with, Soviet scientists initially struggled to make sense of this material, leading them to even have it shot at to get samples . In this video documentary by [That Chernobyl Guy] these struggles by scientists both in and outside the USSR to comprehend this wholly new material are detailed. Much like trinitite – created by a US nuclear weapons test – these are amalgamations of material combined under extreme conditions. In the case of the ChNPP accident , the botched turbine spin-up test and disabling of all safeties by the operators allowed the bottom core chain reaction to run unconstrained, producing the massive steam explosion th...

If you spend any time near a gym, you may be familiar with Bluetooth heart rate monitors — a small pack of electronics mounted on a strap round the chest which can relay heart rate data to an external logger or display. We’re pleased to see [Milos Rasic]’s project then, an open-source version of one of those monitors . The heart rate capture is done by an AD8232, while the Bluetooth part is handled by a Seeed Studio XAIO ESP32 board. Power is provided by a single 3.7 V cell, with a boost converter to push that up to 5 V. The design omits a charge controller to keep things simple, so figuring out how to top off the cell is left as an exercise — no pun intended — for the user. Software is loaded through the Arduino IDE, which raises the possibility that other ESP32 CPUs could be supported with a bit of modification. All in all it’s a surprisingly simple project, and while the manufactured version is cheap enough it’s still very much worth having ...

[Bas BotBerg] wanted to use a portable Bluetooth thermal printer to run off reports on sensor data collected by an ESP32-C3 microcontroller. But as is so often the case these days, the only official way to interface with the printer was through a proprietary smartphone application provided by the manufacturer. With no documentation on how the thing works, he set out to reverse engineer the printer’s communications protocol so he could control it from the MCU — but the route he took to get there was a bit different than what we usually see, and is an excellent case study for those who might have similar projects in mind. The standard procedure for something like this, if it can be called that, is to use Android’s built-in debugging capability to log Bluetooth communications while running the manufacturer’s application. The resulting file can be fed into Wireshark, and with patience and some educated guesses, you can usually work out the various commands and val...

Being able to monitor voltages and currents is essential for many applications, with the national electrical grid being no exception. The obvious complication here is that the voltages and currents are massively higher than for those other applications, making safely monitoring these somewhat of an engineering challenge. The used systems for current monitoring are detailed by [Jordan Taylor], also known as [The Electric Brit], in an explainer of grid-level current transformers (CTs) and associated elements that help to provide galvanic isolation for safe current measurements. Even if the basic principles remain the same, when you’re dealing with currents of 5 kA and more, the associated clearances and penalties for getting a detail wrong increasingly correspondingly. The CTs help to implement over-current protection (OCP), over-voltage protection (OVP) as well as differential protection, which is useful to detect leakage and shorts, which could also happen inside the CT if the w...