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25 Articles

Turning An ATX PSU Into A Variable Bench Supply

May 23, 2024 by 92 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” →

Fail Of The Week: A Potentially Lethal Tattoo Removal Laser Power Supply

March 24, 2024 by 8 Comments

Caveat emptor is good advice in general, but in the wilds of eBay, being careful with what you buy could be life-saving. To wit, we present [Les Wright]’s teardown and very ginger power-up of an eBay tattoo-removal laser power supply.

Given that [Les] spent all of around $100 on this widowmaker, we’re pretty sure he knew what he was getting himself into. But he likely wasn’t quite prepared for the scale of the sketchiness this thing would exhibit. The deficiencies are almost too many to number, starting with the enclosure, which is not only made completely of plastic but assembled from individual sheets of flat plastic stock that show signs of being glued together by hand. Even the cooling water tank inside the case is pieced together this way, which probably led to the leaks that corroded the PCBs. Another assembly gem is the pair of screws the big energy storage capacitor is jammed under, presumably to hold it in place — because nothing says quality like a BOM that can’t spring for a couple of cable ties. Click through the break to read more and see the video.

Continue reading “Fail Of The Week: A Potentially Lethal Tattoo Removal Laser Power Supply” →

TypeMatrix EZ-Reach 2030 Is Better Than Your Laptop Keyboard

May 4, 2021 by 38 Comments

Maybe you’re not ready to take the leap into a full-on ergonomic split keyboard. That’s okay, that’s cool, that’s understandable. They’re weird! Especially ones like my Kinesis Advantage with the key bowls and such. But maybe your poor pinkies are starting to get tired and you’re ready to start using your thumbs for more than just the space bar. Or you want to be able to type ‘c’ properly, with your middle finger.

In that case, the TypeMatrix could be the keyboard for you. Or maybe for travel you, because it’s designed as a quasi-ergonomic, orthonormal layout travel keyboard to pair with your laptop, and as such it sits directly over a laptop keyboard without blocking the track pad. (How do people use those things, anyway?)

Of course, you could use this as a desktop keyboard as well, although it’s unfortunate that Control and Shift are stuck on the pinkies. More about that later.

First Impressions

When I saw this keyboard on eBay, I was attracted by two things: the layout, and the dedicated Dvorak light. (And, let’s be honest — the price was right.) I’ve always found myself generally turned off by chocolate bar-style ortholinear keebs because they’re so incredibly cramped, but this one seemed a more acceptable because of the slight split.

The first thing I noticed was the fantastic number pad integration. The different colored keycaps are a nice touch, because the gray makes the number pad stand out, and the red Delete is easy to find since Num Lock is squatting in the upper right corner. Why does Delete always feel like an afterthought on compact keebs? I also like the location of the arrows, and it makes me think of the AlphaSmart NEO layout. Unfortunately, it comes at the cost of burying the right hand Enter down in no-man’s land where you can’t exactly hit it blindly with great accuracy right away. If only you could swap Shift and Enter without messing up the number pad!

Continue reading “TypeMatrix EZ-Reach 2030 Is Better Than Your Laptop Keyboard” →

Rare Diode Threatens Coast Guard’s Arctic Ambitions

March 14, 2021 by 164 Comments

The United States Coast Guard heavy icebreaker Polar Star is literally a one-of-a-kind ship. After its sister Polar Sea was deactivated in 2010 it became the most powerful icebreaker in the fleet, and one of only two US icebreakers capable of operating in the treacherous polar regions. The vessel is critical to protecting America’s scientific and economic interests in the Arctic, but according to a recent article in Business Insider, the ship’s age and scarcity of spare parts is making an already difficult mission even harder.

In the article, Captain William Woityra specifically mentions that the ship’s diesel-electric propulsion system is running on borrowed time as the diodes used in its AC/DC rectifier are no longer manufactured. With none remaining in the Coast Guard’s inventory, the crew has had to turn to eBay to source as many spares as possible. But once their hoard runs out, Captain Woityra fears his ship will be dead in the water:

We’ve got a few dozen of these in a box on a shelf, when they’re gone, the ship will not be able to run anymore. It’s really kind of disconcerting … that this ship, and this operation, and the US’s icebreaking presence in the Arctic is reliant on a box of spare parts that … there are no more of.”

The 45 year old ship received a $60 million refit in 2013, but that was only expected to extend the hard-working vessel’s life by 8 to 10 years. There was a proposal for a far more thorough overhaul, one which potentially would have keep the Polar Star in service until nearly 2040; but with an estimated cost of $400 million, Congress decided to go with the more economical stop-gap refit.