DIY Bench PSU Looks Like A Million Bucks But Is Easy On The Budget

April 27, 2022 by Ryan Flowers 29 Comments

As one becomes more and more involved in hobbies that involve electronics of almost any kind, it becomes necessary to graduate from wall warts and USB power breakout boards and move up to something more substantial. One great way to do this is to repurpose an old computer PSU, and that’s exactly what the excellent writeup by [Mukesh Sankhla] shows us how to do.

Starting with an ATX power supply from a derelict computer that was otherwise heading to to the bin, [Mukesh] walks us through the teardown of the power supply as well as how we can rebuild it in a snazzy 3d printed case complete with a voltage readout.

Now it’s easy to say “Sure, this is just another ATX PSU project” but the care that went into making a nice case adds a lot to build. There’s another element that is extremely important: The power resistor across the 5 Volt power bus. There are cheap kits online that will break out an ATX PSU into banana plugs, but they omit this vital piece. Depending on the ATX power supply being used, they may be unstable without the load.

The project also leaves a lot of room for adding your own hacks such as variable voltage and current limiting. We think this PSU would be a great (and great looking) addition to any hacker’s workbench. If ATX Power Supply get your electrons flowing, check out this entire computer built into a gutted ATX PSU.

Hackaday Prize 2022: Glass Tube Solar Thermionic Converters

April 27, 2022 by Lewin Day 13 Comments

Typically, if you want to convert solar energy into electrical energy, you use either photovoltaic (PV) cells, or you use the sunlight to create steam to turn a turbine. Both of these methods are well-established and used regularly in both small- and grid-scale applications. However, [Nick Poole] wanted to investigate an alternative method, using thermionic converters for solar power generation.

[Nick] has been gearing up to produce various styles of vacuum tubes, and noted that the thermionic effect that makes them work could also be used to generate electricity. They are highly inefficient and produce far less power than a photovoltaic solar cell, meaning they’re not in common use. However, as [Nick] notes, unlike PV cells etched in silicon, a thermionic converter can be built with basic glassworking tools, requiring little more than a torch, a vacuum pump, and a spot welder.

Experiments with a large lens to focus sunlight onto a 6V3A diode tube showed promise. [Nick] was able to generate half a volt, albeit at a tiny current, with the design not being optimized for thermionic conversion. Further experiments involved electrically heating a pair of diode tubes, which was able to just barely light an LED at 1.7 V and a current of 7.5 uA. The conversion efficiency was a lowly 0.00012%, around 5 orders of magnitude worse than a typical PV cell.

[Nick]’s hope is that he can produce a tube designed specifically to maximize thermionic conversion for energy generation purposes. It’s likely there is some low-hanging fruit in terms of gains to be made simply by optimizing the design for this purpose, even if the technique can’t compete with other solar generation methods.

In any case, we’re eager to see what [Nick] comes up with! We love to see makers building tubes in their own home workshops.

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2022 Hackaday Prize: Get Your Planet-Friendly Power On!

April 27, 2022 by Elliot Williams 5 Comments

Time flies! This weekend marks the end of the first stage of the 2022 Hackaday Prize, and your chance to enter your alternative-energy projects. There are ten $500 prizes up for grabs, and there’s still time to whip up a project page over on Hackaday.io to showcase it.

In this round, we’re looking for projects that harvest their own energy — solar, wind, heat, vibration, you name it — or projects that make it easier to collect, store, or use renewable energy. Whether this is microwatts or megawatts, the scale of the project is up to you! As long as it’s using or making it easier to use clean energy, we want to see it.

So far, we’ve seen some great projects, ranging from a optimizes the tilt angle of a home solar installation to a demonstration of using a new type of lithium-ion capacitor to add solar power to smaller projects. We really love [MartMet]’s simple Bluetooth thermometer hack, which adds a supercapacitor and solar cell to an outdoor thermometer, and then uses hacked firmware to log the charge status over a year of use! We’re suckers for good data.

The sun is not the only game in town, though. There are a surprising number of projects based on human energy production in emergency situations, from cranking to shaking. Thermionic converters were new to us, but we love explorations of fringe tech. Other traditional favorites like wind and water may make more sense for larger applications. And don’t forget how you’re going to store all this juice you’ve collected.

[Nick Poole]’s thermionic converter array

[Anuradha Gunawardhana]’s 18650 Pack

In short, we’ve got a bunch of great entries, but we’re still missing yours! There’s no minute like the last minute: if you’ve done some work in clean or renewable energy, set yourself up a Hackaday.io project page now. You’ll help make all our projects cleaner, and stand a good chance of taking home some real money to boot!

Once we’ve handled power, the next round is “Reuse, Recycle, Revamp” where any tech that uses recycled parts or facilitates reuse, repair, or recycling is fair game!

No-Laser CNC Engraver Is Something New Under The Sun

April 27, 2022 by Dan Maloney 28 Comments

Hooking up a laser to a CNC gantry isn’t exactly an Earth-shattering innovation, but it does make for a useful tool. Even a cheap diode laser mounted to an old 3D printer can do engraving, marking, or even light-duty cutting. But what about a laser engraver without the laser? Can that be of any use?

Apparently, the answer is yes, if you can harness the power of the sun. That’s what [Lucas] did with his solar-tracking CNC engraver, the build of which is shown in the video below. The idea is pretty simple — mount a decent-sized magnifying lens where the laser optics would normally go on a laser engraver, and point the thing at the sun. But as usual, the devil is in the details. The sun has a nasty habit of moving across the sky during the day, or at least appearing to, so [Lucas] has to add a couple of extra degrees of freedom to a regular X-Y CNC rig to track the sun. His tracking sensor is simplicity itself — four CdS photocells arranged with a pair of perpendicular shades, and an Arduino to drive the gimbals in the correct direction to keep all four sensors equally illuminated. He had some initial problems getting the jerkiness out of the control loop, but the tracker eventually kept the whole thing pointing right at the Sun.

So how does it work? Not bad, actually — [Lucas] managed to burn some pretty detailed designs into a piece of wood using just the sun. He mentions adding a shutter to douse the cutting beam to allow raster patterns, but even better might be a servo-controlled iris diaphragm to modulate beam intensity and control for varying sun conditions. He might also check out this solar engraver we covered previously for some more ideas, too.

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The State Of Play In Solid State Batteries

April 27, 2022 by Lewin Day 141 Comments

Electric vehicles are slowly but surely snatching market share from their combustion-engined forbearers. However, range and charging speed remain major sticking points for customers, and are a prime selling point for any modern EV. Battery technology is front and center when it comes to improving these numbers.

Solid-state batteries could mark a step-change in performance in these areas, and the race to get them to market is starting to heat up. Let’s take a look at the current state of play.

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NASA’s Giant SLS Rocket Rolled Back For Repairs

April 27, 2022 by Tom Nardi 33 Comments

There’s little debate that the most exciting move in a rocket’s repertoire is when it launches itself skywards on a column of flame. But failing that, it’s still pretty interesting to see how these massive vehicles get juggled around down here on terra firma before getting fired off into the black. Which is great for anyone interested in NASA’s towering Space Launch System (SLS), as it’s been doing an awful lot of milling about on the ground for a vehicle designed to return humanity to the Moon.

Most recently, the SLS completed a trek from the iconic Vehicle Assembly Building (VAB) to launch pad 39B and back again aboard the same “crawler” that moved the Space Shuttle and Saturn V before it. While the nearly 60-year-old tracked vehicle has received some updates to carry the 98 meter (322 ft) tall booster, clearly the space agency subscribes to the “if it ain’t broke, don’t fix it” school of thought.

The SLS itself however is definitely in need of some work. The rocket was brought out to the pad for the first time on March 18th, where it was to conduct what’s known as a “wet dress rehearsal” — a test of the pre-flight operations, propellant loading, and countdown that includes everything except engine ignition. Unfortunately, the test was plagued with technical issues, and after three attempts, it was decided to bring the rocket back into the VAB to make the necessary repairs to both it and the ground support equipment.

One issue involves a valve in the Interim Cryogenic Propulsion Stage (ICPS), a propulsion module that’s being used on the early SLS flights to provide the trans-lunar injection (TLI) burn that will send the Orion spacecraft on a course towards the Moon. As the name implies, the ICPS is destined to be replaced with the larger Exploration Upper Stage on later missions. There’s also a leak on the launch tower itself that will need to be addressed. After the identified problems are repaired and some adjustments are made, the SLS will once again be rolled out to the pad to reattempt the launch rehearsal.

Now in development for over a decade, the Space Launch System has been plagued with technical issues and delays. At the same time, commercial launch providers like SpaceX have moved the state of the art forward considerably, leading many to wonder if the mind-bogglingly expensive rocket will be able to compete with in-development vehicles such as Starship and New Glenn. The fact that missions which were previously assigned to the SLS have started to get shifted over to commercial rockets would seem to indicate that even NASA is losing confidence in their flagship program.

Building Reaction Wheels With Python And LEGO

April 27, 2022 by Lewin Day 3 Comments

Reaction wheels are useful things, typically used by satellites to keep themselves oriented the right way up in space. Turning the reaction wheel creates an equal and opposite torque in the spacecraft, allowing it to point and rotate itself accurately. The same technique also works here on Earth, and [Brick Experiment Channel] decided to build one out of LEGO to control an inverted pendulum.

The initial design using a small LEGO wheel on an inverted pendulum was only able to work reliably over a 4-degree angle from the vertical. Upgrading the wheel to a larger, heavier one enabled the wheel to instead work over a 28-degree range instead.

A MPU9250 inertial measurement unit was pressed into service for control of the reaction wheel, fitted to the base of the pendulum and read by a Raspberry Pi. The Pi takes accelerometer and gyroscope readings, and then controls the motor on the pendulum with a PID controller to keep the inverted pendulum upright.

The video goes into a great deal of detail on what it takes to make the pendulum run smoothly. From changes to the control coefficients to measuring the motor’s back EMF, [Brick Experiment Channel] demonstrates everything required to make the pendulum robust to outside perturbances.

The inverted pendulum is a great way to learn about control theory, as we’ve seen time and again.

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