Review And Teardown Of Economical Programmable DC Power Supply

June 24, 2021 by Donald Papp 14 Comments

[Kerry Wong] isn’t afraid to get his hands dirty, and is always more than willing to open things up and see what makes them tick. This time, he reviews and tears down the Topshak LW-3010EC programmable DC power supply, first putting the unit through its paces, then opens it up to see how it looks on the inside.

The Topshak LW-3010EC is in a family of reasonably economical power supplies made by a wide variety of manufacturers, which all share many of the same internals and basic construction. This one is both programmable as well as nice and compact, and [Kerry] compares and contrasts it with other power supplies in the same range as he tests the functions and checks over the internals.

Overall, [Kerry] seems pleased with the unit. You can watch him put the device through its paces in the video embedded below, which ends with him opening it up and explaining what’s inside. If you’ve ever been curious about what’s inside one of these power supplies and how they can be expected to perform, be sure to fire up the video below the page break.

Speaking of power supplies, most of us have ready access to ATX power supplies. They are awfully capable pieces of hardware, and hackable in their own way. Our own Jenny List will tell you everything you need to know about the ATX power supply, and how to put it to new uses.

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Rocky Linux Is Ready For Prime Time!

June 24, 2021 by Jonathan Bennett 23 Comments

For some small percentage of the Hackaday crowd, our world got turned upside down at the end of last year, when Red Hat announced changes to CentOS. That distro is the official repackage of Red Hat Enterprise Linux, providing a free, de-branded version of RHEL. The big problem was that CentOS 8 support has been cut way short, ending at the end of 2021 instead of the expected 2029. This caused no shortage of consternation in the community, and a few people and companies stepped forward to provide their own CentOS alternative, with AlmaLinux and Rocky Linux being the two most promising. AlmaLinux minted their first release in March, but the Rocky project made the decision to take things a bit slower. The wait is over, and the Rocky Linux 8.4 release is ready.

Not only are there ISOs for new installs, there is also a script to convert a CentOS 8 install to Rocky. Now before you run out and convert all your CentOS machines, there are a few caveats. First, the upgrade script is still being tested and fixed as problems are found. The big outstanding issue is that Secure Boot isn’t working yet. The process of spinning up a new Secure Boot shim and getting it properly signed is non-trivial, and takes time. The plan is to do an 8.4 re-release when the shim is ready, so keep an eye out for that, if you need Secure Boot support.

The future looks bright for enterprise Linux, with options such as Rocky Linux, AlmaLinux, and even CentOS Stream. It’s worth noting that Rocky has a newly formed company behind it, CIQ, offering support if you want it. The Rocky crew is planning a launch party online on June 25th, so tune in if that’s your thing. Regardless of which Linux OS you run, it’s good to have Rocky in the game.

Hacked AC Window Unit Split In Half To Cool The Garage

June 24, 2021 by Tom Nardi 34 Comments

It’s getting into the hot summer months for those of us in the Northern Hemisphere, and for many Hackaday readers, that means its time to get the old window air conditioner out of storage and lug it back into position. But what if you’re trying to cool a space that doesn’t have a convenient window? In that case, this clever conversion that [Infrared] came up with to keep his garage cool might be of interest.

Basically, he’s taken the classic window AC and turned it into an impromptu ductless unit. By rotating the evaporator coils into a vertical position and lengthening the compressor wires, he was able to make the center of the AC thin enough that he could close his garage door over it. The back of the unit looks largely untouched, but the front side has a real Mad Max vibe going on; with sheet metal, exposed wiring, and a couple of fans thrown in for good measure. Fine for the garage or workspace, but probably not a great choice for the kid’s room.

[Infrared] says the hacked up AC can get his garage 18 degrees cooler than the outside air temperature in its current form, but he hopes the addition of some high CFM computer fans will not only improve performance, but let him make the new front panel look a bit neater. Though even in its current form, this is far from the most ridiculous DIY AC project we’ve seen in recent memory.

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Fat Tire Bike Turned Hubless

June 24, 2021 by Danie Conradie 45 Comments

Bicycle wheels have looked pretty much the same for over a century, and for very good reason: It works. [The Q] decided to ignore reason for a bit and focus on looks, so he built a fat tire bike without any hubs or spokes.

To make this work, he fabricated two sets of ring shaped “hubs” about the size of the rims, with a series of ball bearings around the circumference for the rims to roll around. The original forks were cut short and welded to a set of brackets that bolt to new hubs. This further complicates the back end as there’s nowhere to attach the sprocket cassette. The original rear hub, cassette and disc brake was moved to the inside of the frame. This drives the rear wheel using a second chain attached to a large ring sprocket mounted directly on the rim. The front brake was simply eliminated.

While this new design won’t be taking on existing bicycles, we doubt practicality was a priority in the build. It’s definitely a head turner, and we can’t help but see an opportunity to go even further and build a TRON bicycle.

Just recently, [The Q] turned another fat tire bike into an all-wheel-drive extreme off-roader. For another pedal-powered head turner, check out the strandbeest bicycle.

Active Ball Joint Uses Spherical Gear

June 24, 2021 by Al Williams 40 Comments

A common CAD operation is to take a 2D shape and extrude it into a 3D shape. But what happens if you take a gear and replicate it along a sphere and then rotate it and do it again? As you can see in the video below, you wind up with a porcupine-like ball that you can transfer power to at nearly any angle. There’s a paper describing this spherical gear as part of an active ball joint mechanism and even if you aren’t mechanically inclined, it is something to see.

The spherical gear — technically a cross spherical gear — is made from PEEK and doesn’t look like it would be that difficult to fabricate. There’s also a simpler version known as a monopole gear in the drive system that provides three degrees of freedom.

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ISS Gets Roll-Out Solar Panels In Post-Shuttle Fix

June 24, 2021 by Tom Nardi 18 Comments

Astronauts are currently installing the first of six new solar arrays on the International Space Station (ISS), in a bid to bolster the reduced power generation capability of the original panels which have now been in space for over twenty years. But without the Space Shuttle to haul them into orbit, developing direct replacements for the Stations iconic 34 meter (112 foot) solar “wings” simply wasn’t an option. So NASA has turned to next-generation solar arrays that roll out like a tape measure and are light and compact enough for the SpaceX Dragon to carry them into orbit.

Space Shuttle *Atlantis* carrying part of the ISS truss.

Considering how integral the Space Shuttle was to its assembly, it’s hardly a surprise that no major modules have been added to the ISS since the fleet of winged spacecraft was retired in 2011. The few small elements that have been installed, such as the new International Docking Adapters and the Nanoracks “Bishop” airlock, have had to fit into the rear unpressurized compartment of the Dragon capsule. While a considerable limitation, NASA had planned for this eventuality, with principle construction of the ISS always intended to conclude upon the retirement of the Shuttle.

But the International Space Station was never supposed to last as long as it has, and some components are starting to show their age. The original solar panels are now more than five years beyond their fifteen year service life, and while they’re still producing sufficient power to keep the Station running in its current configuration, their operational efficiency has dropped considerably with age. So in January NASA announced an ambitious timeline for performing upgrades the space agency believes are necessary to keep up with the ever-increasing energy demands of the orbiting laboratory.

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Mechanically Multiplexed Flip-Dot

June 24, 2021 by Danie Conradie 11 Comments

Flip dots displays are timeless classics, but driving the large ones can quickly turn into a major challenge. The electromagnets require a lot of current to operate, and the driver circuits can get quite expensive. [James Bruton] wanted to build his own, but followed a bit of a different route, building a mechanically multiplexed flip dot (ball?) display.

Each of the dots on [James]’ 5×3 proof of concept is a bistable mechanical mechanism that can either show or hide a ping pong ball sized half sphere. Instead of using electromagnets, the dots are flipped by a row of micro servos mounted on a moving carriage behind the display. The mechanism is derived from one of [James]’ previous projects, a mechanical multiplexer. Each dot mechanism has a hook at the back of the mechanism for a servo to push or pull to flip the dot. A major disadvantage of this design is the fact that the servo horn must match the state of the dot before moving through the hook, otherwise it can crash and break something, which also reduces the speed at which the carriage can move.

This build was just to get a feel for the concept, and [James] already has several ideas for changes and improvements. The hook design can certainly change, and a belt drive would really speed things up. We think this mechanical display is a very interesting design challenge, and we are interested to hear how our readers would tackle it? Let us know in the comments below.

Recently we covered a 3D printed flip dot display for the first time. It’s still small and [Larry Builds] is working out the kinks, but we would love to see it eventually match the mesmerising effect of Breakfast’s large installations.