Turning An ATX PSU Into A Variable Bench Supply

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”

Retrotechtacular: How Not To Use Hand Tools

Whatever you’re doing with your hand tools, by the US Army’s lights, you’re probably doing it wrong. That seems to be the “Green Machine’s” attitude on pliers and screwdrivers, at least, the main stars of this 1943 War Department training film on the horrors of tool abuse.

As kitschy as the film might be, they weren’t wrong. That’s especially true about the dreaded slip-joint pliers, which seem to find their way onto everyone’s list of unloved tools and are shown being used for their true purpose — turning nuts and bolt heads from hexagons into circles. Once that gore is wrapped up, we’re treated to the proper uses of pliers, including the fascinating Bernard-style parallel jaw pliers. We can recall these beauties kicking around the bottom of Dad’s tool kit and being entranced by the mechanism used to keep the jaws parallel and amplify the force applied. Sadly, those pliers are long gone now; Tubalcain did a great review of these pliers a few years back if you need a refresher.

A selection of screwdrivers gets the same treatment, complete with dire warnings against using them as prybars and chisels. Also against the Army Way is using the wrong size screwdriver for the job, lest you strip the head of the screw or break the tool itself. It has to be said that the Plomb Tool Company of Los Angeles, which produced the film, made some fantastic-looking screwdrivers back in the day. The square shanks on some of those straight screwdrivers are enormous, and the wooden handles look so much more comfortable than the greebled-up plastic nonsense manufacturers seem to favor these days. Also interesting is the reference to the new-fangled Phillips screw, not to mention the appearance of a Yankee-style spiral ratcheting screwdriver, another of Dad’s prized acquisitions that thankfully is still around to this day.

What strikes us about these military training films is how many of them were produced. No subject seemed too mundane to get a training film made about it, and so many were made that one is left wondering how there was any time left for soldiering after watching all these films. But really, it’s not much different today, when we routinely pull up a random YouTube video to get a quick visual demo of how to do something we’ve never tried before. The medium may have changed, but visual learning is still a thing.

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Tool-Building Mammals

It’s often said of us humans that we’re the only “tool-using mammals”. While not exclusive to the hacker community, a bunch of us are also “tool-building mammals” when we have the need or get the free time. I initially wanted to try to draw some distinction between the two modes, but honestly I think all good hackers do both, all the time.

We were talking about the cool variety of test probes on the podcast, inspired by Al Williams’ piece on back probes. Sometimes you need something that’s needle-thin and can sneak into a crimp socket, and other times you need something that can hold on like alligator clips. The infinite variety of jigs and holders that make it easier to probe tiny pins is nothing short of amazing. Some of these are made, and others bought. You do what you can, and you do what you need to.

You can learn a lot from looking at the professional gear, but you can learn just as much from looking at other hackers’ bodge jobs. In the podcast, I mentioned one of my favorite super-low-tech hacks: making a probe holder out of a pair of pliers and a rubber band to hold them closed. Lean this contraption onto the test point in question and gravity does the rest. I can’t even remember where I learned this trick from, but I honestly use it more than the nice indicator-arm contraptions that I built for the same purpose. It’s the immediacy and lack of fuss, I think.

So what’s your favorite way of putting the probe on the point? Home-made and improvised, or purpose-built and professional? Or both? Let us know!

Understand Your Tools: Finger Exercises

A dip meter is basically a coil of wire that, when you excite it, you can use to tell if something inside that coil is resonating along. This lets you measure unknown radio circuits to figure out their resonant frequency, for instance. This week, we featured a clever way to make a dip meter with a nanoVNA, which is an odd hack simply because a dip meter used to be a common spare-parts DIY device, while a vector network analyzer used to cost more than a house.

Times have changed, and for the better. Nowadays, any radio amateur can pick up a VNA for less than the cost of all but the cheesiest of walkie talkies, putting formerly exotic test equipment in the hands of untrained mortals. But what good is a fancy-pants tool if you don’t know how to use it? Our own Jenny List faced exactly this problem when she picked up a nanoVNA, and her first steps are worth following along with if you find yourself in her shoes.

All of this reminded me of an excellent series by Mike Szczys, “Scope Noob”, where he chronicled his forays into learning how to use an oscilloscope by running all of the basic functions by working through a bunch of test measurements that he already knew the answer to.

It strikes me that we could use something like this for nearly every piece of measuring equipment. Something more than just an instruction manual that walks you through what all the dials do. Something that takes you through a bunch of example projects and shows you how to use the tool in question through a handful of projects. Because these days, access to many formerly exotic pieces of measuring gear has enabled many folks to have gear they never would have had before – and all that’s missing is knowing how to drive them.

Change The Jingle In Your Makita Charger Because You Can

Lots of things beep these days. Washing machines, microwaves, fridge — even drill battery chargers. If you’re on Team Makita, it turns out you can actually change the melody of your charger’s beep, thanks to a project from [Real-Time-Kodi].

The hack is for the Makita DR18RC charger, and the implementation of the hack is kind of amusing. [Real-Time-Kodi] starts by cutting the trace to the buzzer inside the charger. Then, an Arduino is installed inside the charger, hooked up to the buzzer itself and the original line that was controlling it. When it detects the charger trying to activate the buzzer, it uses this as a trigger to play its own melody on the charger instead. The Arduino also monitors the LEDs on the charger in order to determine the current charge state, and play the appropriate jingle for the situation.

It’s an amusing hack, and one that could certainly confuse the heck out of anyone expecting the regular tones out of their Makita charger. It also shows that the simple ways work, too — there was no need to dump any firmware or decompile any code.

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Hackaday Links: November 12, 2023

Somebody must really have it in for Cruise, because the bad press just keeps piling up for the robo-taxi company. We’ve highlighted many of the company’s woes in this space, from unscheduled rendezvous with various vehicles to random acts of vandalism and stupid AI pranks. The hits kept coming as California regulators pulled the plug on testing, which finally convinced parent company General Motors to put a halt to the whole Cruise testing program nationwide. You’d think that would be enough, but no — now we learn that Cruise cars had a problem recognizing children, to the point that there was concern that one of their autonomous cars could clobber a kid under the right conditions. The fact that they apparently knew this and kept sending cars out for IRL testing is a pretty bad look, to say the least. Sadly but predictably, Cruise has announced layoffs, starting with the employees who supported the now-mothballed robo-taxi fleet, including those who had the unenviable job of cleaning the cars after, err, being enjoyed by customers. It seems a bit wrongheaded to sack people who had no hand in engineering the cars, but then again, there seems to be a lot of wrongheadedness to go around.

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Arduino-Controlled Coil Winder

Coil winders are a popular project because doing the deed manually can be an incredibly tedious and time consuming task. After building one such rig, [Pisces Printing] wanted to find even further time savings, and thus designed an improved, faster version.

At it’s heart, it’s a straightforward design, using a linear rail and a leadscrew driven by a stepper motor. Control is via an Arduino Nano, with a few push buttons and a 16 x 2 LCD display for user feedback.

Often, completing a first build will reveal all manner of limitations and drawbacks of a design. In this case, the original winder was improved upon with faster stepper motors to cut the time it took to wind a coil. A redesigned PCB also specified a better buck converter power supply to avoid overheating issues of the initial design. A three-jaw lathe-style chuck was also 3D printed for the build to allow easy fixing of a coil bobbin.

Designing custom tools can be highly satisfying in and of itself, beyond the productivity gains they offer. Video after the break.

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