Hackaday Prize 2023: This Differential Scope Probe Is Smarter Than It Looks

A differential probe, a device for measuring the voltage between two points in a circuit rather than the voltage between a point and ground, it an extremely useful addition to any electronics bench. Inside such a probe you’ll usually find a fancy op-amp working as a differential amplifier, and for correct operation they require careful adjustment to null out DC bias and achieve the maximum common mode rejection. We particularly like [Craig D]’s probe, because these adjustments are taken care of automatically by a microcontroller.

The analogue path provides a lesson for anyone interested in instrumentation signal path design, with the signal conditioning and compensation circuits feeding an AD8130 differential amplifier. Another amplifier samples the output voltage and feeds it to the ADC in the microcontroller. Common mode adjustment is taken care of by a digital potentiometer chip, and DC offset by the microcontroller’s DAC. Controlling all this is an ATSAMD10 chip, and the power is derived from the scope’s USB interface.

All in all it’s an extremely well-executed device, and one we’d be happy to have on our bench at any time. It’s by no means the first differential probe we’ve brought you, here’s another.


Hackaday Prize 2023: An Anti-Tremor Handle, With No Electronics

Many of us will have seen the various active assistive devices which have appeared over the last few years to help people with a hand tremor. Probably the best known was a fork with a set of servos and an accelerometer, that kept the end of the utensil steady despite the owner’s hand movements. It’s a field which has the potential to help many people, but it’s undeniable that such technology comes with a cost.

What if the same effect could be achieved passively, without all those electronics? It’s something [Jacob] is investigating with his mechanical anti-tremor cup handle. It’s a university project completed as part of his studies so it’s very much a work-in-progress which if we’re being fair isn’t quite there yet, but we think the potential in this idea of bringing a useful assistive device at least bears further attention.

The write-up is available as a Norwegian PDF file so takes a little bit of Google Translate cut and pasting for an Anglophone. Sadly due to what must be report format requirements set by the university it’s long on procedure and shorter on engineering calculations than we’d like, but there’s an attempt to calculate the properties of the helical springs in each of the joints to match the likely forces. Our intuition is that the design as shown would require significantly more mass on the end of it than that of the mug and beverage alone to achieve some form of stability, but despite that as we said it’s an interesting enough idea that it deserves more thought.

Hand tremor assistive devices have appeared more than once on these pages before, here’s one for soldering that enlists the aid of a camera gimbal.

Hackaday Prize 2023: Abuse A Reference Chip For A Cheap Instrument

A Rogowski coil is a device for measuring AC current that differs from a conventional current transformer in that it has no need to encircle the conductor whose current it measures. They’re by no means cheap though, so over time we’ve seen some interesting variations on making one without the pain in the wallet. We particularly like [Stephen]’s one, because he eschews exotic devices for an interesting hack on a familiar chip. He’s taken the venerable TL431 voltage reference chip and turned it into an op-amp.

We had to look at the TL431 data sheet for this one and shamefacedly admit that since we’d only ever used the chip as a voltage reference, we hadn’t appreciated this capability. In this mode, it’s a op-amp with the inverting input connected to a fixed rail, so it can accept a feedback network to its non-inverting input just like any other. He’s using it as both integrator and amplifier, as well as, of course, in a more conventional power supply.

We like the instrument, and the use of the TL431 in an unexpected manner is the cherry on the cake. Here’s a previous Rogowski circuit using more conventional parts. You can dive a bit more into the theory, too.

Hackaday Prize 2023: AutoDuct Smart Air Duct

Modern building techniques are relying more and more on passive elements to improve heating and cooling efficiencies, from placing windows in ways to either absorb sunlight or shade it out to using high R-value insulation to completely sealing the living space to prevent airflow in or out of the structure. One downside of sealing the space in this fashion, though, is the new problem of venting the space to provide fresh air to the occupants. This 3D printed vent system looks to improve things.

Known as the AutoDuct, the shutter and fan combination is designed to help vent apartments with decentralized systems. It can automatically control airflow and also reduces external noise passing through the system using a printed shutter mechanism which is also designed to keep out cold air on windy days.

A control system enables features like scheduling and automatic humidity control. A mobile app is available for more direct control if needed. The system itself can also integrate into various home automation systems like Apple’s HomeKit.

A 100% passive house that’s also as energy-efficient as possible might be an unobtainable ideal, but the closer we can get, the better. Some other projects we’ve seen lately to help climate control systems include this heat pump control system and this automatic HVAC duct booster fan system.

Hackaday Prize 2023: The Gearing Up Challenge Finalists

If there’s more to life than just a workshop full of tools, it’s probably a workshop full of tools that you’ve built yourself. At least that was the thinking behind the recently concluded “Gearing Up” challenge of the 2023 Hackaday Prize, which unsurprisingly generated quite a list of entries for our judges to review and whittle down to their top ten favorite tools, jigs, fixtures, and general labor-savers.

Having piqued the interest of our crack team of judges, these ten projects have not only earned a spot in the 2023 Hackaday Prize Finals, but they’ll also get a $500 cash prize to boot. But the heat is really on now; like all the finalists from the previous rounds, they’ve only got until October to get their projects as far along as they can before the final round. The grand prize is grand indeed — $50,000 in cash and a residency at the Supplyframe Design Lab in Pasadena!

We’re really getting down to the wire here, but it’s worth taking a little time out to look at some of the Gearing Up challenge winners, and what they came up with to make life in the shop a little easier. And don’t forget — the one who dies with the most tools wins!

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Hackaday Prize 2023: Gen5X A Generatively Designed 5-Axis 3D Printer

[Ric Real] is entering the 2023 Hackaday Prize with the Gen5X, a generatively designed 3D printed five-axis 3D printer. The concept is not a new one, with the type of construction being seen a few times here and there. In addition to the usual three directions of motion, we’re familiar with, with the cartesian bot design, these types of machines add an additional two rotation axes, one which can swing the build platform front and back around the X-axis, and a second that provides rotation around the Z-axis. These combined motions give rise to some very interesting capabilities, outside of our familiar 3D printing design constraints.

As for the generative side of things, this is a largely theoretical idea. Essentially the concept is that the machine’s design can be iteratively updated and optimised for performance to fit into the constraints of available hardware such as motors and other ‘vitamins’ needed to create the next generation of machines. The design files should be parameterised enough such that this optimisation process can be automated, potentially via input from AI, but we suspect we’re a way off from that yet. Whether this project as yet satisfies any of these lofty goals remains to be seen, but do keep an eye on it if you’re so inclined. There is a Fusion 360 project here to dig into, but if you’re not interested in the research side of the project, but just want to build a 5-axis machine to play with, then you can find the project source on the GitHub Page.

If this feels familiar, you’d be on the right track, as we covered at least one other 5D printer recently. We have also touched upon generative design at least once. We’re sure we will see more on this topic in the future.

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Hackaday Prize 2023: 10 KW Electronic Load

[tinfever] needed a high-power benchtop electronic load for an upcoming project, and by their own admission decided foolishly to build their own. And we’re glad they did. The thing is, whilst this isn’t exactly a super-cheap project to build, buying a commercial offering with a capability of 10 kW and up to 30 kW pulsed, is going to cost an absolute fortune.

A selection of small resistors

Built inside a cubic frame using what appears to be standard 2020 aluminum rails and fixturing, the modular construction is nice and clean, with plenty of space around the load boards to allow the cooling air to circulate.

The operating principle is very simple; custom PCBs act in parallel to provide any load needed, by switching in the on-board load resistor. Each load board handles all the details of switching and dumping the power due to the inductance in the system wiring and the wire-wound resistors themselves.

Whilst we know that wire-wound resistors are reverse-wound to minimize inductance, there will still be some, and each load board will contribute a little more when the whole system is scaled up. Also, each load PCB handles its own temperature sensing, and current measurement passing these data off to the control PCB. A front-end connector PCB provides a variety of connection options to interface to the DUT (Device Under Test.) The system controller is based around an STM32 processor which deals with quite a lot more than you might think is needed on a first look.

The sense currents from each load need to be sensed, scaled, and summed to keep the overall load accuracy within the 1% spec. Also, it is on duty for PWM control of the cooling fans, handling the user interface, and any other remote connectivity. There are a lot of details on the project page, as we’re only skimming the surface here. If you’re interested in building an active load, this is a project you really should be digging into.

We shall watch with interest for when [tinfever] scales up this eight-slot prototype to the full specification of 52 stages! When working with power applications, there comes a point when you really need an electronic load, and to that end, here’s one with a very specific use case to get you started.

There is also the option of buying something cheap from the usual sources and hacking on some custom firmware to adapt it a little to your needs.