Kritik sah

Perpetual motion devices are either a gag, a scam, or as in the case of this particular toy that [Big Clive] bought on AliExpress, a rather fascinating demonstration of a contact-free inductive sensor combined with a pulsed magnet boost for the metal ball. A cool part about the device is that it comes with a completely clear enclosure, so you can admire its internals while it’s operating. Less cool was that after unboxing the device wasn’t working as the detector wasn’t getting the 12 V it needs to operate, requiring a bit of repairing first. The crucial part of the perpetual motion device schematic with the sensor, MCU and coil. (Credit: bigclivedotcom, YouTube) Based on the label on the bottom of the device with the creative model identifier P-toy-002 , its standby current is 10 µA which ramps up to 3 A when it’s operating. This makes sense when you look at the two core components: the industrial inductive detector, and a rather big electromagnet that’s driven by a bank of thre...

The big problem with Low Earth Orbit is, oddly enough, air resistance. Sure, there’s not enough air to breathe in space, but there is enough to create drag when you’re whipping around the planet at 28,000 km/h (17,000 mph) or more. Over time, that adds up to a decaying orbit. [Eager Space] recently did a video summarizing a paradoxical solution: go even lower, and let the air work for you. So called air-breathing satellites would hang out in very low earth orbit– still well above the Karman line, but below 300 km (186 miles)– where atmospheric drag is too dominant for the current “coast on momentum” satellite paradigm to work. There are advantages to going so low, chiefly for communications (less latency) and earth observation (higher resolutions). You just need to find a way to fight that drag and not crash within a couple of orbits. It turns out this space isn’t totally empty (aside from the monoatomic oxygen) as missions have been at very low orbits using conventional, Xenon-fuel...

While we often get a detailed backstory of the projects we cover here at Hackaday, sometimes the genesis of a build is a bit of a mystery. Take [maurycyz]’s radiation survey meter modifications , for instance; we’re not sure why such a thing is needed, but we’re pretty glad we stumbled across it. To be fair, [maurycyz] does give us a hint of what’s going on here by choosing the classic Ludlum Model 3 to modify. Built like a battleship, these meters would be great for field prospecting except that the standard G-M tube isn’t sensitive to gamma rays, the only kind of radiation likely not to be attenuated by soil. A better choice is a scintillation tube, but those greatly increase the background readings, making it hard to tease a signal from the noise. To get around this problem and make rockhounding a little more enjoyable, [maurycyz] added a little digital magic to the mostly analog Ludlum. An AVR128 microcontroller taps into the stream of events the meter measures via the scintilla...

A book of mechanical actions is a wondrous thing — mechanically inclined children have lost collective decades pouring over them over the generations. What could possibly be better? Why, if the mechanisms in the book were present, and moved! That’s exactly what [AxelMadeIt] produced for a recent video . Being just four pages, you might argue this is but a pamphlet. But since it takes up a couple inches of shelf space, it certainly looks like a book from the outside, which is exactly what [AxelMadeIt] was going for. To get a more book-like spine, his hinge design sacrificed opening flat, but since the pages are single-sided, that’s no great sacrifice. At only 6 mm (1/4″) thick, finding printable mechanisms that could actually fit inside was quite a challenge. If he was machining everything out of brass, that would be room for oodles of layers. But [Axel] wanted to print the parts for this book, so the mechanisms need to be fairly thick. One page has a Roberts linkage and a vault-lock...

This week Jonathan and Rob chat with Paulus Schoutsen about Home Assistant, ESPHome, and Music Assistant, all under the umbrella of the Open Home Foundation. Watch to see Paulus convince Rob and Jonathan that they need to step up their home automation games! https://www.home-assistant.io/ https://esphome.io/ https://www.music-assistant.io/ https://www.openhomefoundation.org/ Did you know you can watch the live recording of the show right on our YouTube Channel ? Have someone you’d like us to interview? Let us know, or contact the guest and have them contact us! Take a look at the schedule here . Direct Download in DRM-free MP3. If you’d rather read along, here’s the transcript for this week’s episode . Places to follow the FLOSS Weekly Podcast: Spotify RSS Theme music: “Newer Wave” Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 4.0 License from Blog – Hackaday https://ift.tt/J1R8yzo

The video cassette tape was really the first successful home video format; discs just couldn’t compete back in the early days. That’s not to say nobody tried, however, with RCA’s VideoDisc a valiant effort that ultimately fell flat on its face. However, the forgotten format did have one benefit, in that it led to the development of an entirely new kind of microscope, as explained by IEEE Spectrum. The full story is well worth the read; the short version is that it all comes down to capacitance. RCA’s VideoDisc format was unique in that it didn’t use reflective surfaces or magnetic states to represent data. Instead, the data was effectively stored as capacitance changes. As a conductive stylus rode through an undulating groove in a carbon-impregnated PVC disc, the capacitance between the stylus and the disc changed. This capacitance was effectively placed into a resonant circuit, where it would alter the frequency over time, delivering an FM signal that could be decoded into video and...

[Curious Scientist] has been working with some image sensors. The latest project around it is a 6K camera . Of course, the sensor gives you a lot of it, but it also requires some off-the-shelf parts and, of course, some 3D printed components. An off-the-shelf part of a case provides a reliable C mount. There’s also an IR filter in a 3D-printed bracket. The processor gets hot, so he used different heat sinks and a fan, too. Overall, this isn’t much custom electronics, but this is an excellent example of assembling existing parts with high-quality 3D printed components. Heat-set inserts provide a tripon mount. There’s also a custom HDMI monitor mount if you don’t want to use your phone as a viewfinder. One neat oddity that helps is a USB-A cable that splits into three USB-C connectors. Of course, only one of them has data lines. The other two feed power to different parts of the camera. A good-looking build. At a glance, you could easily think this was a commercial product. We do l...