Turning An ATX PSU Into A Variable Bench Supply

May 23, 2024 by Zoe Skyforest 93 Comments

Bench power supplies can sometimes be frustratingly expensive and also kind of limited. If you’re enterprising and creative, though, you can create your own bench supply with tons of features, and it doesn’t have to break the bank either. Do what [Maker Y] did—grab an ATX supply and get building!

ATX power supplies work as a great basis for a bench power supply. They have 12 volt, 3.3 volt, and 5 volt rails, and they can supply a ton of current for whatever you might need. [Maker Y] decided to break out these rails on banana plugs for ease of access, and fused them for safety, too. But the build doesn’t stop there. [Maker Y] also added a buck-boost converter to provide a variable voltage output from 1 to 30 volts for added flexibility. As a nice final touch, the rig also features a pair of USB A ports compatible with Quick Charge 3.0, for keeping smart devices charged while working in the lab.

[Caelestis Workshop] also designed a fully enclosed version if you prefer that style. Check it out on Instructables.

No matter which way you go, it’s a pretty simple build, with a bunch of off-the-shelf parts tossed together in a 3D printed housing. Ultimately, though, it’s got more functionality than a lot of cheap off-the-shelf bench supplies. You can build it just about anywhere on Earth where you can get cheap eBay parts via post. Continue reading “Turning An ATX PSU Into A Variable Bench Supply” →

99% Partspiration

July 8, 2023 by Elliot Williams 37 Comments

Thomas Edison once said that genius was 1% inspiration and 99% perspiration. That doesn’t leave much room for partspiration.

I’m working on a top-secret project, and had to place a parts order on AliExpress with a minimum order quantity of five in order to get decent shipping times. No big deal, financially, and it’s always great to have spares as backup for the ones you fry.

But as I started lighting up the little round smartwatch displays to put them through their paces, I started thinking of all sorts of ways that I could use something like this. I had no idea how easy to drive they were, or frankly, how good they looked in person. When you get a round display in your hands, you find that you need dial indicators everywhere.

And then my son came by and said “Oh neat. I want one!” and started thinking up all sorts of gizmos that I could put them in. Two of them would make awesome eyes, and he’s been on a chameleon kick – the animal, you know. So we’re looking for chameleon eye animations online.

And all of a sudden, I have more projects lined up than I have remaining screens. I’m calling this phenomenon “partspiration”. You know, when you figure out how to use something and then you see uses for it everywhere? Time to place another Ali order.

Gearing Up for the Hackaday Prize

And don’t forget, we just started the next round of the Hackaday Prize: Gearing Up. In this challenge round we want to see your best DIY tools, jigs, and workflow accelerators. Custom reflow plates, home-built power supplies, or even software tools – as long as it helps you get the job done, it has a place here. You’ve got until Aug. 8 to get your entry finished, but head on over to Hackaday.io and get started now.

Using FreeCAD To Replace OEM Parts

June 10, 2023 by Bryan Cockfield 46 Comments

As much as we might all like it if manufacturers supported their products indefinitely with software updates or replacement parts, this just isn’t feasible. Companies fail or get traded, technologies evolve, and there’s also an economic argument against creating parts for things that are extremely old or weren’t popular in the first place. So, for something like restoring an old car, you might have to resort to fabricating replacement parts for your build on your own. [MangoJelly] shows us how to build our own replacement parts in FreeCAD in this series of videos.

The build does assume that the original drawings or specifications for the part are still available, but with those in hand FreeCAD is capable of importing them and then the model scaling to match the original specs shown. This video goes about recreating a hinge on an old truck, so with the drawings in hand the part is essentially traced out using the software, eventually expanding it into all three dimensions using all of the tools available in FreeCAD. One of the keys to FreeCAD is the various workbenches available that all have their own sets of tools, and being able to navigate between them is key to a build like this.

FreeCAD itself is an excellent tool for anyone repairing old vehicles like this or those making 3D prints, designing floorplans for houses, or really anything you might need to model in a computer before bringing the idea into reality. It does have a steep learning curve (not unlike other CAD software) so it helps to have a video series like this if you’re only just getting started or looking to further hone your design skills, but the fact that it’s free and open-source make it extremely attractive compared to its competitors.

Continue reading “Using FreeCAD To Replace OEM Parts” →

FET: Fun Endeavors Together

May 2, 2023 by Arya Voronova 42 Comments

Last time, we’ve looked over FET basics, details, nuances and caveats. Basics aren’t all there is to FETs, however – let’s go through real-world uses, in all their wonderful variety! I want to show you a bunch of cool circuits where a friendly FET, specifically a MOSFET, can help you – and, along the way, I’d also like to introduce you to a few FETs that I feel like you all could have a good long-term friendship with. If you don’t already know them, that is!

Driving Relays

Perhaps, that’s the single most popular use for an NPN transistor – driving coils, like relays or solenoids. We are quite used to driving relays with BJTs, typically an NPN – but it doesn’t have to be a BJT, FETs often will do the job just as fine! Here’s an N-FET, used in the exact same configuration as a typical BJT is, except instead of a base current limiting resistor, we have a gate-source resistor – you can’t quite solder the BJT out and solder the FET in after you have designed the board, but it’s a pretty seamless replacement otherwise. The freewheel (back EMF protection) diode is still needed for when you switch the relay and the coil produces wacky voltages in protest, but hey, can’t have every single aspect be superior.

The reason you can drive it the same way is quite simple: in the usual NPN circuit, the relay is driven by a 3.3 V or a 5 V logic level GPIO, and for small signal FETs, that is well within Vgs. However, if your MCU has 1.8 V GPIOs and your FET’s Vgs doesn’t quite cut it, an NPN transistor is a more advantageous solution, since that one will work as long as you can source the whatever little current and the measly 0.7 V needed.

Continue reading “FET: Fun Endeavors Together” →

The BSides: More Curious Uses Of Off-the-shelf Parts

April 24, 2023 by Sonya Vasquez 10 Comments

Off-the-shelf stock parts are the blocks from which we build mechanical projects. And while plenty of parts have dedicated uses, I enjoy reusing them in ways that challenge what they were originally meant for while respecting the constraints of their construction. Building off of my piece from last time, I’d like to add to your mechanical hacking palette with four more ways we can re-use some familiar off-the-shelf parts. Continue reading “The BSides: More Curious Uses Of Off-the-shelf Parts” →

Showing a new generation ATTiny on an SMD breakout plugged into a breadboard, being programmed

Come Learn About New ATtiny Generations

November 27, 2022 by Arya Voronova 12 Comments

As the chip shortage hit, a lot of the familiar ATtiny chips have become unavailable and overpriced, and it mostly stayed the same since then. If you ever searched for “ATtiny” on your favourite electronics component retailer website, however, you’d notice that there’s quite a few ATtiny chips in stock most of the time – just that they’re from a much newer generation than we commonly see, with incompatible pinouts, slightly different architecture and longer model numbers like 412 and 3227. [David Johnson-Davies] from [technoblogy] is here to clarify things, and provide a summary of what the new ATtiny generations have to offer.

In 2019, he posted about 0- and 1-series ATtiny chips, comparing them to the ATtiny series we knew, decyphering the part numbering scheme for us, and providing a comparison table. Now, he’s returned to tell us about the 2- series ATtiny chips, merging the comparison tables together so that you can quickly evaluate available parts by their ROM/RAM size and the SMD package used. He also describes which peripherals are available on which series, as well as nuances in peripheral operation between the three generations. In the end, he reminds us of a simple way to program all these new parts – as it stands, you only need a USB-UART adapter and a 4.7K resistor.

Over the last decades, we’ve seen plenty of inspiring ATtiny projects – squeezing out everything we could out of 5 GPIOs, or slightly more for larger-package ATtiny chips. [David] has been setting an example for us, bringing projects like this function generator, this continuity tester, or an IR receiver with an OLED screen for diagnostics – all with an ATtiny85. It’s not the just pin count that’s a constraint, but the RAM and flash amounts as well – nevertheless, people have fit machine learning and an entire graphics stack into these chips before. If you’re stuck at home unable to do anything, like many of us were during lockdowns, you can always breadboard an ATtiny and see just how much you can get done with it.

A Hacker Walks Into A Trade Show: Electronica 2022

November 22, 2022 by Elliot Williams 24 Comments

Last week, the world’s largest electronics trade fair took place in Munich, so I had to attend. Electronica is so big that it happens only once every two years and fills up 14 airplane hangars. As the fairly generic name suggests, it covers anything and everything having to do with electronics. From the producers of your favorite MLCC capacitors to the firms that deliver them to your doorstep, from suppliers of ASIC test equipment to the little shop that’ll custom wind toroids for you, that’s a pretty wide scope. Walking around, I saw tomorrow’s technology today from the big players, but I also picked up some ideas that would be useful for the home gamer.

When I first walked in, for instance, I ran into the Elantas booth. They’re a company that makes flexible insulation and specialty industrial coatings. But what caught my eye was a thermoformed plastic sheet with circuit traces on it. To manufacture them, they cut out copper foil, glue it to a flat plastic sheet with a glue that has a little give, and then put it all together into a vacuum former. The result is a 3D circuit and organically formed substrate in one shot. Very cool, and none of the tech for doing that is outside of the reach of the determined hacker.

The Cool Stuff

All of the stands, big or small, try to lure you in with some gimmick. The big fish, firms with deep pockets, put up huge signs and open bars, and are staffed by no shortage of salespeople in suits. The little fish, on the other hand, have to resort to showing you the cool stuff that they do, and it’s more often the application engineers sitting there, ready to talk tech. You can guess which I found more interesting.

For instance when I walked up to an obviously DIY popcorn popper that was also showing 5000 FPS footage of kernels in mid-pop, I had to ask. The company in question was a small UK outfit that made custom programmable power supplies and digital acquisition gear that interfaced with it. You could plug in their box to some temperature probes, fire off the high-speed video camera, and control the heating and cooling profile without writing any code. Very sweet. Continue reading “A Hacker Walks Into A Trade Show: Electronica 2022” →