Turning An ATX PSU Into A Variable Bench Supply

May 23, 2024 by Lewin Day 90 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” →

Is This The World’s Smallest Multichannel Voltmeter?

May 22, 2024 by Jenny List 8 Comments

The instrument which probably the greatest number of Hackaday readers own is likely to be the humble digital multimeter. They’re cheap and useful, but they’re single-channel, and difficult to incorporate into a breadboard project. If you’ve ever been vexed by these limitations then [Alun Morris] has just the project for you, in the world’s smallest auto-ranging multichannel voltmeter. It’s a meter on a tiny PCB with a little OLED display, and as its name suggests, it can keep an eye on several voltages for you.

At its heart is an ATtiny1614 microcontroller on a custom PCB, but for us the part we most like lies not in that but in the prototype version made on a piece of protoboard. There’s considerable soldering skill in bending surface mount components to your will on this material, and though these aren’t quite the smallest parts it’s still something that must have required some work under the magnifier.

All of the code and hardware details can be found in the GitHub repository, and for your viewing pleasure there’s a video showing it in action which we’ve placed below.

Continue reading “Is This The World’s Smallest Multichannel Voltmeter?” →

Hands On: AD409-Max Microscope

May 22, 2024 by Al Williams 18 Comments

It used to be that only the most well-equipped home electronics lab had a microscope. However, with SMD parts getting smaller and smaller, some kind of microscope is almost a necessity.

Luckily, you can get USB microscopes for a song now. If you’re willing to spend a little more, you can get even get microscopes that have little LCD screens. However, there are some problems with the cheaper end of these microscopes.

Many of them have small and wobbly stands that aren’t very practical. Some don’t leave you much room to get a soldering iron in between the lens and the part. Worse still, many cheap microscopes have trouble staying still when you have to push buttons or otherwise make adjustments to the device.

It seems like every time a new generation of microscopes aimed at the electronics market arrives on the scene, many of the earlier flaws get taken care of. That’s certainly the case with the Andonstar AD409-Max.

Continue reading “Hands On: AD409-Max Microscope” →

Students’ Leaf Blower Suppressor To Hit Retail

May 18, 2024 by Tom Nardi 81 Comments

Electric leaf blowers are already far quieter than their gas-powered peers, but they still aren’t the kind of thing you’d like to hear first-thing on a Saturday morning. Looking to improve on the situation, a group of students from Johns Hopkins University have successfully designed a 3D printed add-on that manages to significantly reduce the noise generated by a modern electric leaf blower without compromising the amount of air it’s able to move. The device has proven to be so successful in tests that Stanley Black & Decker is looking to put a commercial version of the device on store shelves within the next two years.

The team says the first part of the problem was identifying where the noise was actually coming from. After taking an example leaf blower apart and studying all of its moving components, they determined that most of the noise produced wasn’t mechanical at all — what you’re actually hearing is the complex cacophony of high-speed air rushing out of the nozzle. With this knowledge in hand, they isolated the frequencies which were the harshest to the human ear and focused on canceling them out.

Continue reading “Students’ Leaf Blower Suppressor To Hit Retail” →

Flexures Keep This Printed Displacement Sensor In Line

May 18, 2024 by Dan Maloney 4 Comments

When the job at hand is measuring something with micron-range precision, thoughts generally turn to a tool with a Mitutoyo or Starrett nameplate. But with a clever design and a little electronics know-how, it turns out you can 3D print a displacement sensor for measuring in the micron range for only about $10.

While the tool that [BubsBuilds] came up with isn’t as compact as a dial indicator and probably won’t win any industrial design awards, that doesn’t detract from its usefulness. And unlike a dial indicator — at least the analog type — this sensor outputs an easily digitized signal. That comes courtesy of a simple opto-interrupter sensor, which measures the position of a fine blade within its field of view. The blade is attached to a flexure that constrains its movement to a single plane; the other end of the flexure has a steel ball acting as a stylus. In use, any displacement of the stylus results in more or less light being received by the phototransistor in the opto-interrupter; the greater the deflection, the less light and the lower the current through the transistor. In addition to the sensor itself, [Bub] printed a calibration jig that allows precision gauge blocks or simple feeler gauges to be inserted in front of the stylus. The voltage across the emitter resistor for these known displacements is then used to create a calibration curve.

[Bub] says he’s getting 5-micron repeatability with careful calibration and multiple measurements of each gauge block, which seems pretty impressive to us. If you don’t need the digital output, this compliant mechanism dial indicator might be helpful too. Continue reading “Flexures Keep This Printed Displacement Sensor In Line” →

Big Server Fan Becomes Fume Extractor

May 16, 2024 by Lewin Day 12 Comments

[Anthony Kouttron] wanted a fume extractor for his personal electronics lab, but he didn’t like the look of the cheap off-the-shelf units that he found. Ultimately, he figured it couldn’t be that hard to build own portable fume extractor instead.

The build is based around a mighty 110-watt centrifugal fan from an IBM server that’s rated at approximately 500 CFM. It’s a hefty unit, and it should be, given that it retails at over $200 on DigiKey. [Anthony] paired this fan with off-the-shelf HEPA and activated carbon filters. These are readily available from a variety of retailers. He didn’t want to DIY that part of the build, as the filter selection is critical to ensuring the unit actually captures the bad stuff in the air. He ended up building a custom power supply for the 12-volt fan, allowing it to run from common drill batteries for practicality’s sake.

Few of us have need for such a beefy fume extractor on the regular. Indeed, many hobbyists choose to ignore the risk from soldering or 3D printing fumes. Still, for those that want a beefy fume extractor they can build themselves, it might be worth looking over [Anthony]’s initial work.

We’ve seen some other great DIY fume extractors before, too. Even those that use drill batteries! If you’ve been cooking up your own solution, don’t hesitate to drop us a line!

Adaptive Chef’s Knife Provides Better Leverage

May 16, 2024 by Donald Papp 25 Comments

[Colleen] struggled with using a chef’s knife to cut a variety of foods while suffering from arthritis in her wrist and hand. There are knives aimed at people with special needs, but nothing suitable for serious work like [Colleen]’s professional duties in a commercial kitchen.

As a result, the IATP (Illinois Assistive Technology Program) created the Adaptive Chef’s Knife. Unlike existing offerings, it has a high-quality blade and is ergonomically designed so that the user can leverage their forearm while maintaining control.

The handle is durable, stands up to commercial kitchen use, and is molded to the same standards as off-the-shelf knife handles. That means it’s cast from FDA-approved materials and has a clean, non-porous surface. The pattern visible in the handle is a 3D printed “skeleton” over which resin is molded.

Interested? The IATP Maker Program makes assistive devices available to Illinois residents free of charge (though donations in suggested amounts are encouraged for those who can pay) but the plans and directions are freely available to anyone who wishes to roll their own.

Assistive technology doesn’t need to be over-engineered or frankly even maximally efficient in how it addresses a problem. Small changes can be all that’s needed to give people meaningful control over the things in their lives in a healthy way. Some great examples are are this magnetic spoon holder, or simple printed additions to IKEA furnishings.