Why Electric Trains Sound The Way They Do

October 5, 2024 by Jenny List 20 Comments

If you’re a seasoned international rail traveler you will no doubt have become used to the various sounds of electric locomotives and multiple units as they start up. If you know anything about electronics you’ll probably have made the connection between the sounds and their associated motor control schemes, but unless you’re a railway engineer the chances are you’ll still be in the dark about just what’s going on. To throw light on the matter, [Z&F Railways] have a video explaining the various control schemes and the technologies behind them.

It’s made in Scotland, so the featured trains are largely British or in particular Scottish ones, but since the same systems can be found internationally it’s the sounds which matter rather than the trains themselves. Particularly interesting is the explanation of PWM versus pattern mode, the latter being a series of symmetrical pulses at different frequencies to create the same effect as PWM, but without relying on a single switching frequency as PWM does. This allows the controller to more efficiently match its drive to the AC frequency demanded by the motor at a particular speed, and is responsible for the “gear change” sound of many electric trains. We’re particularly taken by the sound of some German and Austrian locomotives (made by our corporate overlords Siemens, by coincidence) that step through the patterns in a musical scale.

Not for the first time we’re left wondering why electric vehicle manufacturers have considered fake internal combustion noises to make their cars sound sporty, when the sound of true electrical power is right there. The video is below the break.

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An Open Source Mirrorless Camera You’d Want To Use

October 5, 2024 by Jenny List 18 Comments

Making a digital camera is a project that appears easy enough, but it’s one whose complexity increases depending on the level to which a designer is prepared to go. At the simplest a Raspberry Pi and camera module can be stuck in a 3D printed case, but in that case, the difficult work of getting the drivers and electronics sorted out has already been done for you.

At the other end of the scale there’s [Wenting Zhang]’s open source mirrorless digital camera project, in which the design and construction of a full-frame CCD digital camera has been taken back to first principles. To understand the scale of this task, this process employs large teams of engineers when a camera company does it, and while it’s taken a few years and the software isn’t perhaps as polished as your Sony or Canon, the fact it’s been done at all is extremely impressive.

Inside is a Kodak full-frame sensor behind the Sony E-mount lens, for which all the complex CCD timing and acquisition circuitry has been implemented. The brains of the show lie in a Xilinx Zynq ARM-and-FPGA in a stack of boards with a power board and the CCD board. The controls and battery are in a grip, and a large display is on the back of the unit.

We featured an earlier version of this project last year, and this version is a much better development with something like the ergonomics, control, and interface you would expect from a modern consumer camera. The screen update is still a little slow and there are doubtless many tweaks to come, but this really feels close to being a camera you’d want to try. There’s an assembly video which we’ve placed below the break, feast your eyes on it.

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HackFest Enschede: The Type Of Indoor Event We Wanted All Along

October 4, 2024 by Jenny List 6 Comments

I’m sitting at a table writing this in the centre of a long and cavernous industrial building, the former print works of a local newspaper, I’m surrounded by hardware and software hackers working at their laptops, around me is a bustling crowd admiring a series of large projects on tables along the walls, and the ambient sound is one of the demoscene, chiptunes, 3D-printed guitars, and improbably hurdy-gurdy music. Laser light is playing on the walls, and even though it’s quite a journey from England to get here, I’m home. This is Hackfest Enschede, a two-day event in the Eastern Dutch city which by my estimation has managed the near-impossible feat of combining the flavour of both a hacker event and a maker faire all in one, causing the two distinct crowds to come together.

The Best Of Both Worlds, In One Place

To give an idea of what’s here it’s time for a virtual trip round the hall. I’ll start with the music, aside from the demosceners there’s Printstruments with a range of 3D-printedmusical instruments, and Nerdy Gurdy, as you may have guessed, that hacker hurdy-gurdy I mentioned. This is perhaps one of few places I could have seen a spontaneous jam session featuring a 3D-printed bass and a laser-cut hurdy-gurdy. Alongside them were the Eurorack synthesisers of Sound Force, providing analogue electronic sounds aplenty. Continue reading “HackFest Enschede: The Type Of Indoor Event We Wanted All Along” →

The Raspberry Pi 500 Hints At Its Existence

October 4, 2024 by Jenny List 61 Comments

It’s fairly insignificant in the scheme of things, and there’s no hardware as yet for us to look at, but there it is. Tucked away in a device tree file, the first mention of a Raspberry Pi 500. We take this to mean that the chances of an upgrade to the Pi 400 all-in-one giving it the heart of a Pi 5 are now quite high.

We’ve remarked before that one of the problems facing the Raspberry Pi folks is that a new revision of the regular Pi no longer carries the novelty it might once have done, and certainly in hardware terms (if not necessarily software) it could be said that the competition have very much caught up. It’s in the Compute Module and the wildcard products such as the all-in-one computers that they still shine then, because even after several years of the 400 it’s not really seen an effective competitor.

So we welcome the chance of an all-in-one with a Pi 5 heart, and if we had a wish list for it then it should include that mini PCI-E slot on board for SSDs and other peripherals. Such a machine would we think become a must-have for any space-constrained bench.

Retrotechtacular: Another Thing Your TV No Longer Needs

October 2, 2024 by Jenny List 23 Comments

As Hackaday writers we don’t always know what our colleagues are working on until publication time, so we all look forward to seeing what other writers come up with. This week it was [Al Williams] with “Things Your TV No Longer Needs“, a range of gadgets from the analogue TV era, now consigned to the history books. On the bench here is a device that might have joined them, so in taking a look at it now it’s by way of an addendum to Al’s piece.

When VHF Was Not Enough

In a Dutch second-had store while on my hacker camp travels this summer, I noticed a small grey box. It was mine for the princely sum of five euros, because while I’d never seen one before I was able to guess exactly what it was. The “Super 2” weighing down my backpack was a UHF converter, a set-top box from before set-top boxes, and dating from the moment around five or six decades ago when that country expanded its TV broadcast network to include the UHF bands. If your TV was VHF it couldn’t receive the new channels, and this box was the answer to connecting your UHF antenna to that old TV.

It’s a relatively small plastic case about the size of a chunky paperback book, on the front of which is a tuning knob and scale in channels and MHz, on the top of which are a couple of buttons for VHF and UHF, and on the back are a set of balanced connectors for antennas and TV set. It’s mains powered, so there’s a mains lead with an older version of the ubiquitous European mains plug. Surprisingly it comes open with a couple of large coin screws on the underside, so it’s time to take a look inside. Continue reading “Retrotechtacular: Another Thing Your TV No Longer Needs” →

Seven Day Movement Makes A Rubbish Clock

September 29, 2024 by Jenny List 10 Comments

We see a lot of clocks here at Hackaday. Some of them are better than others, but this one from [John Graham-Cumming] is definitely a rubbish clock. It performs the simple yet vital task of keeping track of which day is which when it comes to trash collection.

The big revelation for us from this project is that the standard plastic battery clock mechanism which you’ll no doubt be familiar with from many cheap clocks can also be bought with gearing for a weekly rather than daily revolution. The physical hack is therefore a pretty simple one of mounting the movement with a single hand over a face showing the waste collections, and the write-up goes into more depth about the code for creating custom SVG clock faces. We’re already thinking of interesting stuff that can be done with one of these movements.

Meanwhile, we like this clock, but it’s certainly not the first trash indicator we’ve seen.

An ESP32 Delivers Perfect Slot Car Control

September 28, 2024 by Jenny List 5 Comments

If your memory of slot cars as a childhood toy is of lightweight controllers with wire-wound rheostats inside, then you’re many years behind the state of the art when it comes to competitive slot car racing. In that world the full force of modern electronics has been brought to keeping the car on the road, and as an example here’s [Maker Fabio] with a cutting edge controller that has an ESP32 at its heart.

It’s obvious that a huge amount of attention has gone into both the physical design of the unit and its software, and the result speaks for itself. The trigger sits on a proper bearing, and the sensor is a Hall-effect device on the PCB. The firmware was written in the Arduino IDE, and through the trigger and a rotary encoder all of its options can be configured on a small OLED display. Individual settings can be configured for each car, and we’re treated to a full explanation of this in the video.

We are told that the files for both software and hardware will be released in due course, as this is still a work in progress for the moment. The video meanwhile provides ample demonstration, so we look forward to the release.

It’s a surprise to find relatively few projects from the slot car world on these pages, given the amount of potential there is in them for electronic improvement. Here’s one from a few years ago though.

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