Sketch of the UED setup at EPFL, 1) Electron gun, 2) High-Voltage connector, 3) Photo-cathode, 4) Anode, 5) Collimating solenoid, 6) Steering plates, 7) Focusing solenoid, 8) RF cavity, 9) Sample holder, 10) Cryostat, 11) Electron detector, 12) Turbo pump, 13) Ion gauge. Credit: Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2316438121

Using Femtosecond Laser Pulses To Induce Metastable Hidden States In Magnetite

July 20, 2024 by Maya Posch No comments

Hidden states are a fascinating aspect of matter, as these can not normally be reached via natural processes (i.e. non-ergodic), but we can establish them using laser photoexcitation. Although these hidden states are generally very unstable and will often decay within a nanosecond, there is evidence for more persistent states in e.g. vanadates. As for practical uses of these states, electronics and related fields are often mentioned. This is also the focus in the press release by the Ecole Polytechnique Federale de Lausanne (EPFL) when reporting on establishing hidden states in magnetite (Fe₃O₄), with the study published in PNAS (Arxiv preprint link).

[B. Truc] and colleagues used two laser frequencies to either make the magnetite more conductive (800 nm) or a better insulator (400 nm). The transition takes on the order of 50 picoseconds, allowing for fairly rapid switching between these metastable states. Naturally, turning this into practical applications will require a lot more work, especially considering the need for femtosecond pulsed lasers to control the process, which makes it significantly more cumbersome than semiconductor technology. Its main use at this point in time will remain a fascinating demonstration of these hidden states of matter.

Working Through The Art Of Electronics Exercises

July 20, 2024 by Al Williams 10 Comments

[The Engineering Experience] has an ambitious series of videos. He’s working through circuit examples from the awesome book “The Art of Electronics.” In the latest installment, he’s looking at a pulse generator that uses bipolar transistors. So far, there are 43 videos covering different exercises.

If you’ve read the book — and you should — you know the examples and exercises sometimes have little explanation. Honestly, that’s good. You should try to work through them yourself first. But once you have an idea of how it works, hearing someone give their take on it may help you out. In fact, even if you don’t have the book, we’d suggest pausing the video and looking at the circuit to see what you can figure out before playing the explanation. You’ll learn more that way.

Admittedly, some of the early videos will be cakewalks for Hackaday readers. The first few, for example, walk through parallel and series resistors. However, if you are starting out or just want a refresher, you can probably enjoy all of them. The later ones get a bit more challenging.

If you want to double-check your work, you can simulate the circuit, too. Our simulation got 4.79 V and he computed 4.8, which is certainly close enough.

We do love “The Art of Electronics.” The book’s author also enjoys listening for aliens.

Continue reading “Working Through The Art Of Electronics Exercises” →

New Additive Manufacturing Contenders: HIP And Centrifugal Printing

July 20, 2024 by Maya Posch 6 Comments

Additive Manufacturing (AM) is a field of ever-growing importance, with many startups and existing companies seeking to either improve on existing AM technologies or market new approaches. At the RAPID + TCT 2024 tradeshow it seems that we got two more new AM approaches to keep an eye on to see how they develop. These are powder-based Hot Isostatic Pressing (HIP) by Grid Logic and centrifugal 3D printing by Fugo Precision.

Grid Logic demo at RAPID + TCT 2024. (Credit: Ian Wright)

Grid Logic’s HIP uses binder-less powders in sealed containers that are compressed and deposited into a HIP can according to the design being printed, followed by the HIP process. This is a common post-processing step outside of AM as well, but here HIP is used as the primary method in what seems like a budget version of typical powder sintering AM printers. Doubtlessly it won’t be ‘hobbyist cheap’, but it promises to allow for printing ceramic and metal parts with minimal wasted powder, which is a major concern with current powder-based sintering printers.

While Grid Logic’s approach is relatively conservative, Fugo’s Model A printer using centrifugal printing is definitely trying to distinguish itself. It uses 20 lasers which are claimed to achieve 30 µm accuracy in all directions with a speed of 1 mm/minute. It competes with SLA printers, which also means that it works with photopolymers, but rather than messing with FEP film and pesky Earth gravity, it uses a spinning drum to create its own gravitational parameters, along with a built-in parts cleaning and curing system. They claim that this method requires 50% fewer supports while printing much faster than competing commercial SLA printers.

Even if not immediately relevant to AM enthusiasts, it’s good to see new ideas being tried in the hope that they will make AM better for all of us.

This Vintage Computing Device Is No Baby Food

July 20, 2024 by Al Williams 10 Comments

Today, if you want a computer for a particular task, you go shopping. But in the early days of computing, exotic applications needed custom computers. What’s more is that with the expense of computers, you likely got one made that fit exactly what you needed and no more. That led to many oddball one-off or nearly one-off computers during that time frame. Same for peripheral devices — you built what you had to and you left the rest on the drafting table. [Vintage Geek] got his hands on what appears to be one of them: the Gerber Scientific 6200.

While Gerber Scientific is still around, we’ve never heard of the 6200. Based on the serial number, we would guess at least 62 of them were made and this one has an interesting backstory of living in someone’s home who worked at the Pentagon. We presume the tapes were erased before it was sold!

Design-wise, it is pretty standard stuff. A 19-inch rack, a standard tape drive from Kennedy, a power supply, and some cards. The box takes 240 V, so the computer didn’t get powered up, but an examination of the inside looked like this really was a one-off with handwritten labels on masking tape.

We couldn’t tell for sure if the device was a computer itself, or just a tape drive and maybe plotter interface for another computer. If you know anything about this device, we are sure [Vintage Geek] would like to hear from you.

If this does turn out to have a CPU onboard, we’d bet it is bit sliced. If you have a 9-track tape machine, you may have to make your own tapes soon.

Continue reading “This Vintage Computing Device Is No Baby Food” →

2024 Business Card Challenge: CardTunes Bluetooth Speaker

July 20, 2024 by Donald Papp 8 Comments

A business card form factor can be quite limiting, but that didn’t stop [Schwimmflugel] from creating CardTunes, an ESP32-based Bluetooth audio speaker that tried something innovative to deliver the output.

What’s very interesting about this design is the speaker itself. [Schwimmflugel] aimed to create a speaker out of two coils made from flexible circuit board material, driving them with opposite polarities to create a thin speaker without the need for a permanent magnet.

The concept is sound, but in practice, performance was poor. One could identify the song being played, but only if holding the speaker up to one’s ear. The output was improved considerably with the addition of a small permanent magnet behind the card, but of course this compromised the original vision.

Even though the concept of making a speaker from two flexible PCB panel coils had only mixed success, we love seeing this kind of effort and there’s a lot to learn from the results. Not to mention that it’s frankly fantastic to even have a Bluetooth speaker on a business card in the first place.

The 2024 Business Card Challenge is over, but judging by all the incredible entries we received, we’re thinking it probably won’t be too long before we come up with another sized-constrained challenge.

Continue reading “2024 Business Card Challenge: CardTunes Bluetooth Speaker” →

Do Your Research

July 20, 2024 by Elliot Williams 7 Comments

We were talking about a sweet hack this week, wherein [Alex] busts the encryption for his IP web cam firmware so that he can modify it later. He got a number of lucky breaks, including getting root on the device just by soldering on a serial terminal, but was faced with having to reverse-engineer a binary that implemented RSA encryption and decryption.

Especially when they’re done right, and written to avoid side-channel attacks, encryption routines aren’t intuitive, even when you’re looking at the C source. Reversing it from the binary would be a tremendous hurdle.

That’s when [Alex] started plugging in strings he found in the binary into a search engine. And that’s when he found exactly the open source project that the webcam used, which gave him the understanding he needed to crack the rest of the nut.

Never forget! When you’re doing some reverse engineering, whether hardware or software, do a search for every part number and every string you find in memory. If you’re like me, it might feel like cheating a little bit, but it’s just being efficient. It’s what all your hacker heroes say they do, and if you’re lucky, it might just be the break you need too.

Sealed Packs Of Pokémon Cards Give Up Their Secrets Without Opening Them

July 20, 2024 by Donald Papp 31 Comments

[Ahron Wayne] succeeded in something he’s been trying to accomplish for some time: figuring out what’s inside a sealed Pokémon card packet without opening it. There’s a catch, however. It took buying an X-ray CT scanner off eBay, refurbishing and calibrating it, then putting a load of work into testing and scanning techniques. Then finally combining the data with machine learning in order to make useful decisions. It’s a load of work but [Ahron] succeeded by developing some genuinely novel techniques.

While using an X-ray machine to peek inside a sealed package seems conceptually straightforward, there are in fact all kinds of challenges in actually pulling it off. There’s loads of noise. So much that the resulting images give a human eyeball very little to work with. Luckily, there are also some things that make the job a little easier.

For example, it’s not actually necessary to image an entire card in order to positively identify it. Teasing out the individual features such as a fist, a tentacle, or a symbol are all useful to eliminate possibilities. Interestingly, as a side effect the system can easily spot counterfeit cards; the scans show up completely different.

When we first covered [Ahron]’s fascinating journey of bringing CT scanners back to life, he was able to scan cards but made it clear he wasn’t able to scan sealed packages. We’re delighted that he ultimately succeeded, and also documented the process. Check it out in the video below.

Continue reading “Sealed Packs Of Pokémon Cards Give Up Their Secrets Without Opening Them” →