2025-11-07 08:00:29
For the Component Abuse Challenge our hacker [Tim Williams] observes that N-P-N reads the same way forwards and backwards, so… what happens if we reverse bias one? (Note: this remark about N-P-N reading the same forward and backward is a lighthearted joke; in fact the level of doping in the emitter and collector is different so those Ns are not fungible and will exhibit different properties and have different characteristics.)
In the margin you can see how the question was originally posed by Bob Pease back in March 18, 1996.
In his article [Tim] mentions that some transistors are specifically designed to operate when reverse biased, which [Tim] calls “inverted mode”, whereas most transistors are not designed to work in this fashion and that’s the sort of abuse that could damage the component and lead it to malfunction.
But what is Vout? [Tim] reports that he measured approximately -0.4 volts using his high-impedance meter. We tried this experiment in the lab ourselves but we were not able to duplicate [Tim]’s result; however there is a long list of potential reasons for such an outcome. If you do this experiment yourself we would love to hear about your results in the comments section!
If you’re still learning about transistors you might like to check out our five part series on transistors as amplifiers, starting here: Won’t Somebody, Please, Think Of The Transistors!
Thanks to [Tim] for his submission, we wish him the best of luck in the competition!
2025-11-07 05:00:13
Over the decades we have seen a lot of methods for powering LEGO-based contraptions, ranging from LEGO Technic pneumatics to electric motors, but what about steam power? We have all seen those cute little model steam engines that can definitely put out some power. Sure, you can just drop those in like a kind of confused internal combustion engine, or you can try to make a steam engine that actually tries to be directly compatible with LEGO.
While exploring this topic, [Jamie’s Brick Jams] on YouTube found that the primary concern here is simply the very hot steam produced by the boiler. While not a surprise to anyone who has ever run a model steam engine, this poses a major challenge to the thermoplastics used by LEGO.
Obviously a boiler cannot be made out of plastic, but the steam turbine can. That said, material selection here is key, as the hot, wet steam produced by the boiler demolishes PLA parts and ruined the original and very unsafe copper boiler in the process. Ultimately a LEGO Technic-compatible steam turbine was printed in high temperature resistant PAHT-CF and PC filament, which enables a steam-powered LEGO walker to come to life, albeit with a distinct lack of power.
Model steam engine enthusiasts are of course quick to point out that you should try to create dry steam through superheating, definitely add a safety valve and so on, all of which should make for an even more powerful and safe LEGO steam engine. For a rundown of how steam engines work, [Lawrie] did an excellent video on the basics a while back, as well as a video playlist full of demonstrations of both classical Mamod model engines and questionable modern takes.
Suffice it to say that although model steam engines look like toys, they involve fire, hot steam and other fascinating ways to melt things, light them on fire and cause painful injuries, so definitely follow a safety briefing before attempting any of it at home.
2025-11-07 03:30:00
Tagging wildlife is never straightforward in the best of times, but it becomes a great deal more complicated when you’re trying to track flying insects. Instead of trying to use a sensor package, [DeepSOIC] attached tiny, light retroreflectors to bees and hornets, then used a pulsed infrared light mounted on a drone to illuminate them. Two infrared cameras on the drone track the bright dot that indicates the insect, letting the drone follow it. To get a spot bright enough to track in full sunlight, though, [DeepSOIC] had to drive some infrared LEDs well above their rated tolerances.
The LEDs manage to survive because they only fire in 15-µs pulses at 100 Hz, in synchrony with the frame rate of the cameras, rather like some welding cameras. The driver circuit is very simple, just a MOSFET switch driven by an external pulse source, a capacitor to steady the supply voltage, and a current-limiting resistor doing so little limiting that it could probably be removed. LEDs can indeed survive high-current pulses, so this might not really seem like component abuse, but the 5-6 amps used here are well beyond the rated pulse current of 3 amps for the original SFH4715AS LEDs. After proving the concept, [DeepSOIC] switched to 940 nm LEDs, which provide more contrast because the atmosphere absorbs more sunlight around this wavelength. These new LEDs were rated for 5A, so they weren’t being driven so far out of spec, but in tests they did survive current up to 10A.
We’ve seen a similar principle used to drive laser diodes in very high-power pulses a few times before. For an opposite approach to putting every last bit of current through an LED, check out this low-power safety light.
2025-11-07 02:00:49
Everyone has a standard for publishing projects, and they can get pretty controversial. We see a lot of people complain about hacks embedded in YouTube videos, social media threads, Discord servers, Facebook posts, IRC channels, different degrees of open-sourcing, licenses, searchability, and monetization. I personally have my own share of frustrations with a number of these factors.
It’s common to believe that hacking as a culture doesn’t thrive until a certain set of conditions is met, and everyone has their own set of conditions in mind. My own dealbreaker, as you might’ve seen, is open-sourcing of code and hardware alike – I think that’s a sufficiently large barrier for hacking being repeatable, and repeatability is a big part of how hacking culture spreads.
This kind of belief is often self-limiting. Many people believe that their code or PCB source file is not a good contribution to hacking culture unless it meets a certain cleanliness or completeness standard. This is understandable, and I do that, too.
Today, I’d like to argue against my own view, and show how imperfect publishing helps build hacking culture despite its imperfections. Let’s talk about open-source in context of 3D printing.
One little-spoken aspect of 3D printing is how few models are open-source. Printable models published exclusively as STLs are commonplace, STEPs are much less popular, and from my experience, it’s soul-crushingly rare to see a source file attached to a model on Printables. I struggle to say that’s a good thing, and quite obviously, that negatively impacts 3D printing culture – getting into 3D modeling is that much harder if you can’t reference the sources for 95% of models you might get inspired by.
Of course, part of that is that 3D CADs are overwhelmingly closed-source paid software, and there are like five different ones with roughly equal shares of usage. It’s hard to meaningfully share sources from within a paywalled siloized market. Also, unlike software source code, STLs are very much cross-platform. Electronics has a way better analogy for STLs, they’re just like gerbers – gerbers are easy to export, and to inexperienced people, they’ll feel like all that anyone would ever need.
Then, there’s a self-consciousness and perfectionism. While rare, I’ve seen “I will clean this up and publish later” happen in 3D printing spaces too – it’s a thoroughly non-viable promise there too, but I get why people say that, I’ve personally made and failed on such promises a good few times myself. I’m glad that this isn’t a popular excuse so far, but, as more people adopt OpenSCAD, Blender, and FreeCAD, with their universally-accessible files, maybe we’ll see it resurface.
Asking for 3D model sources should probably become part of hacker culture, just like it helped with software. I don’t think it’s great that 3D printing so often implies closed-source 3D models, and undoubtedly that has limited the growth of 3D modeling as a hobby. I strongly wish I could git clone the 3D model projects I find online, and there’s a whole lot of models that are useless to me because I can’t git clone and modify them.
At the same time? 3D printing carries the hacker flag quite strongly, despite the imperfections, and you can notice it by just how often 3D printing appears on our pages. We can and should point at aspects of hacker culture that 3D printing doesn’t yet represent, and while at it, we benefit from the technology, as much as its imperfections hurt us.
Would I argue the same about Discord servers? Mastodon-hosted threads? YouTube videos? GitHub repos with barely-documented code? For sure. There’s no shortage of criticism about those, mostly about accessibility issues. Servers and videos are often not externally discoverable, which is surprisingly painful for hacker culture’s ability to thrive and grow. At the very least, we are badly missing out – for instance, I’d say Discord servers and YouTube videos alike are in dire need of external log/transcript hosting capabilities, and tech-oriented Discord servers specifically could benefit from public logs in the same way that modern Discourse forums have them from the get-go.
That’s for the disadvantages. As for upsides, YouTube videos make hardware hacking into entertainment for potential hackers not enthralled by scrolling through a blog interspersed with pictures, and, they position hacking culture in front of people who’d otherwise miss out on it. Let’s take [DIY Perks], a hugely popular YouTube channel. Would that dual-screen laptop build we covered have worked out great as a blog post, or maybe as a dual post-video, as some hackers do? For sure. At the same time, it gets hacking in front of people’s faces.
Discord blows as a platform, and I’ve written a fair bit about just how much it blows. One such snippet is in the article I wrote about the Beepy project, where the Discord server was crucial to growing Beepy as a community-contributed project. Would people benefit from the Beepy project having publicly available logs? Most certainly, and I’d argue it’s hurt the Beepy project being more externally discoverable. Is that all?
Discord has been an unprecedented communications platform for the Beepy project, and we’d outright lose out if there weren’t hardware hacking communities thriving on Discord, like Hackaday Discord does. I think we should remedy these kinds of problems by building helper tools and arguing for better cultural norms, just like we did with software licenses, because giving up on platforms like Discord currently has a significantly subpar cost-benefit analysis.
What about imperfect code? Sometimes, a hacker figures out a small part of a sensor’s protocol or a basic feature, and as much as the code might be insufficient or hastily written, they publish it. Have you ever stumbled upon such a repository? I have, sometimes I was happy, and sometimes I was disappointed, but either which way, such code tend to require extra work. In the end, I’ve noticed that it almost always helped way more than it hurt, which in turn has eventually led to me publishing more and more.
I think we’d benefit from a culture where “publish later after cleanup” is replaced by “here’s the code, and I might push some cleanup commits later”. It’s a better contribution to hacker culture and to people who enjoy your work, and the “might” part makes it more honest. It’ll also get your publishing muscles in better shape so that you’re quick to post about things you really ought to post about. For what it’s worth, I don’t think it hurts if this is assisted by social media likes, too.
Survival of hacker culture has so far heavily relied on its presence in media all across, and an ability to press the “maybe I can hack too” button in other people’s brains through that presence. That said, every non-open 3D model, Discord server with non-public logs, YouTube channel with non-transcribed videos, or a completely ephemeral TikTok channel, still palpably paves a way for future hackers to join our communities, wherever hackerdom might be within ten years’ time.
I think the key to informational impedance mismatches is making it easier for people to meet the high standards we expect, and helping people meet them where appropriate, in large part, by example. It looks like hacking is strongest when present everywhere, even when some seams, and I hope that this kind of overwhelming presence helps us overcome modern-day unique cultural hurdles in a way we couldn’t hope for just a decade ago.
2025-11-07 00:30:47
Economists have this idea that we live in an efficient market, but it’s hard to fathom that when disposable vapes are equipped with rechargeable lithium cells. Still, just as market economists point out that if you leave a dollar on the sidewalk someone will pick it up, if you leave dollars worth of lithium batteries on the sidewalk, [Chris Doel] will pick them up and build a DIY home battery bank that we really hope won’t burn down his shop.
The Powerwall-like arrangement uses 500 batteries salvaged from disposable vapes. His personal quality control measure while pulling the cells from the vapes was to skip any that had been discharged past 3 V. On the other hand, we’d be conservative too if we had to live with this thing, solid brick construction or not.
That quality control was accomplished by a clever hack in and of itself: he built a device to blow through the found vapes and see if they lit up. (That starts at 3:20 in the vid.) No light? Not enough voltage. Easy. Even if you’re not building a hoe powerbank, you might take note of that hack if you’re interested in harvesting other people’s deathsticks for lithium cells. The secret ingredient was the pump from a CPAP machine. Actually, it was the only ingredient.)
In another nod to safety, he fuses every battery and the links between the 3D printed OSHA unapproved packs. The juxtoposition between janky build and careful design nods makes this hack delightful, and we really hope [Chris] doesn’t burn down his shed, because like the cut of his jib and hope to see more hacks from this lad. They likely won’t involve nicotine-soaked lithium, however, as the UK is finally banning disposable vapes.
In some ways, that’s a pity, since they’re apparently good for more than just batteries — you can host a website on some of these things. How’s that for market efficiency?
2025-11-06 23:00:48
When we talk about HDTV, we’re typically talking about any one of a number of standards from when television made the paradigm switch from analog to digital transmission. At the dawn of the new millenium, high-definition TV was a step-change for the medium, perhaps the biggest leap forward since color transmissions began in the middle of the 20th century.
However, a higher-resolution television format did indeed exist well before the TV world went digital. Over in Japan, television engineers had developed an analog HD format that promised quality far beyond regular old NTSC and PAL transmissions. All this, decades before flat screens and digital TV were ever seen in consumer households!
Japan’s efforts to develop a better standard of analog television were pursued by the Science and Technical Research Laboratories of NHK, the national public broadcaster. Starting in the 1970s, research and development focused on how to deliver a higher-quality television signal, as well as how to best capture, store, and display it.
This work led to the development of a standard known as Hi-Vision, which aimed to greatly improve the resolution and quality of broadcast television. At 1125 lines, it offered over double the vertical resolution of the prevailing 60 Hz NTSC standard in Japan. The precise number was chosen for meeting minimum requirements for image quality for a viewer with good vision, while being a convenient integer ratio to NTSC’s 525 lines (15:7), and PAL’s 625 lines (9:5). Hi-Vision also introduced a shift to the 16:9 aspect ratio from the more traditional 4:3 used in conventional analog television. The new standard also brought with it improved audio, with four independent channels—left, center, right, and rear—in what was termed “3-1 mode.” This was not unlike the layout used by Dolby Surround systems of the mid-1980s, though the NHK spec suggests using multiple speakers behind the viewers to deliver the single rear sound channel.
Hi-Vision referred most specifically to the video standard itself; the broadcast standard was called MUSE—standing for Multiple sub-Nyquist Sampling Encoding. This was a method for dealing with the high bandwidth requirements of higher-quality television. Where an NTSC TV broadcast might only need 4.2 MHz of bandwidth, the Hi-Vision standard needed 20-25 MHz of bandwidth. That wasn’t practical to fit in alongside terrestrial broadcasts of the time, and even for satellite delivery, it was considered too great. Thus, MUSE offered a way to compress the high-resolution signal down into a more manageable 8.1 MHz, with a combination of dot interlacing and advanced multiplexing techniques. The method used meant that ultimately four frames were needed to make up a full image. Special motion-sensitive encoding techniques were also used to limit the blurring impact of camera pans due to the use of the dot interlaced method. Meanwhile, the four-channel digital audio stream was squeezed into the vertical blanking period.
MUSE broadcasts began on an experimental basis in 1989. NHK would eventually begin using the standard regularly on its BShi satellite service, with a handful of other Japanese broadcasters eventually following suit. Broadcasts ran until 2007, when NHK finally shut down the service with digital TV by then well established.
An NHK station sign-on animation used from 1991 to 1994.
The technology wasn’t just limited to higher-quality broadcasts, either. Recorded media capable of delivering higher-resolution content also permeated the Japanese market. W-VHS (Wide-VHS) hit the market in 1993 as a video cassette standard capable of recording Hi-Vision/MUSE broadcast material. The W moniker was initially chosen for its shorthand meaning in Japanese of “double”—since Hi-Vision used 1125 lines which was just over double the 525 lines in an NTSC broadcast.
Later, in 1994, Panasonic released its Hi-Vision LaserDisc player, with Pioneer and Sony eventually offering similar products. They similarly offered 1,125 lines (1,035 visible) of resolution in a native 16:9 aspect ratio. The discs were read using a narrower-wavelength laser than standard laser discs, which also offered improved read performance and reliability.
Sample video from a MUSE Hi-Vision Laserdisc. Note the extreme level of detail visible in the makeup palettes and skin, and the motion trails in some of the lens flares.
The hope was that Hi-Vision would become an international standard for HDTV, supplanting the ugly mix of NTSC, PAL, and SECAM formats around the world. Unfortunately, that never came to pass. While Hi-Vision and MUSE did offer a better quality image, there simply wasn’t much content that was actually broadcast in the standard. Only a few channels in Japan were available, creating a limited incentive for households to upgrade their existing sets. Similarly, the amount of recorded media available was also limited. The bandwidth requirements were also too great; even with MUSE squishing the signals down, the 8.1MHz required was still considered too much for practical use in the US market. Meanwhile, being based on a 60 Hz standard meant the European industry was not interested.
Further worsening the situation was that by 1996, DVD technology had been released, offering better quality and all the associated benefits of a digital medium. Digital television technology was not far behind, and buildouts began in countries around the world by the late 1990s. These transmissions offered higher quality and the ability to deliver more channels with the same bandwidth, and would ultimately take over.
Only a handful of Hi-Vision displays still exist in the world.
Hi-Vision and MUSE offered a huge step up in image quality, but their technical limitations and broadcast difficulties meant that they would never compete with the new digital technologies that were coming down the line. There was simply not enough time for the technology to find a foothold in the market before something better came along. Still, it’s quite something to look back on the content and hardware from the late 1980s and early 1990s that was able, in many ways, to measure up in quality to the digital flat screen TVs that wouldn’t arrive for another 15 years or so. Quite a technical feat indeed, even if it didn’t win the day!
