This here is an example of a photovore or photopopper — it moves toward light using simple logic by charging up a capacitor and employing a voltage monitor to decide when there’s enough to run two tiny vibration motors that make up its legs and feet.
[NanoRobotGeek] started in a great place when they found these 25% efficient monocrystalline solar panels. They will even make the bot move indoors! If you want to build one of these, you can’t beat [NanoRobotGeek]’s guide. Be sure to watch it toddle around in the demo video after the break.
Hackaday Prize 2021 entrant [Philip Ian Haasnoot] has been building a well-polished power bank. But this is no ordinary little power bank the like you would throw in your rucksack for a day out. No, this 2.5 kW luggable power bank is neatly encased in a tough, waterproof Pelican 1550 case, and is suitably decked out with all the power sockets you could possibly need for a long weekend of wilderness camping and photography.
This box sports USB-C and USB 3.0 connectors for gadget charging, as well as 12 VDC cigarette lighter and XT-60 ports for high-drag devices. Also it provides a pair of 120 VAC sockets via an integrated inverter, which at 1.5 kW could run a small heater if you were really desperate, but more likely useful to keep your laptop going for a while. Now if only you could get Wi-Fi out in the desert!
[Philip] doesn’t actually talk much about the solar panels themselves, but we know the box contains a 600 W MPPT boost converter to take solar power in, and feed the LiPo battery pack in the correct manner.
The battery pack is custom-made from salvaged and tested 18650 cells, as you would expect, which we reckon took an absolute age to make by hand. The whole project is nicely finished, and looks like something we’d be happy to throw in the back of the car before heading out into our local wilderness.
As [Philip] says in the project description, it’s a tough job to carry enough power and keep all his drones, cameras and lighting equipment charged, not mention helping prevent the campsite occupants from freezing overnight during the chilly Arizona nights.
Many power bank designs have graced these fair pages over the years, like this rather polished build, and long may they continue to do so.
Researchers claim that using several very thin layers of ferroelectric crystals can lead to significantly better ferroelectric solar cell efficiency. But don’t pull the panels off your roof yet. Conventional cells are still much more efficient than ferroelectric devices — at least, for now.
Unlike conventional silicon-based solar cells, ferroelectric cells don’t depend on a PN junction and — in theory — can be cheaper and easier to produce. However, they typically don’t absorb as much sunlight as other materials.
Light has always been a key part of the classic Game Boy experience. Some of us have fond memories of riding along in the back seat of a car at night, pausing and unpausing the game as the street lights overhead briefly give enough light to see the unlit display. The availability of third party IPS displays for these classic handhelds has largely eradicated this problem today, but as you might expect, the increased power requirements of the more modern screen reduces the system’s runtime.
In the video below, you can see the modification starts by cutting away a large section of the Game Boy’s rear panel to fit the 1000 mAh LiPo battery. The solar panel is then affixed over the back with super glue. A diode is soldered onto the solar cell, and then wired into a charge controller that came with USB-C input. The placement of the charge controller ended up being trickier than expected, but with a little hot glue, it works just fine. Overall this is a simple mod but a brilliant idea.
This isn’t the first solar-powered handheld game system we’ve seen, but it’s nice to see the idea revisited and expanded on, particularly regarding ergonomics. In addition, we love the incredible detail of narration that’s given as this hack slowly takes shape. Video after the break.
The magnetosphere is the region of space surrounding the earth in which the earth’s magnetic field has most influence, and unlike the tidy pattern of magnetic field surrounding a bar magnet that you might have seen with iron filings at school, it’s distorted by the constant buffeting of the solar wind. This means that a significant quantity of potential energy is stored in its compression, and it’s this energy that Electro-Harmonix have their eye on.
Like Fox Mulder: we want to believe. Unfortunately the trouble with such ideas is readily visible with a quick web search; they attract a significant number of what one might charitably call cranks, and there is no shortage of unsubstantiated claims surrounding conspiracy theories, silenced genus inventors, and their mystery devices. Weird and wonderful descriptions and cryptic circuit diagrams abound, so separating the wheat if there is any from the inevitable chaff becomes a challenge. We respect that the Electro-Harmonix team are professional engineers who we hope are unlikely to become caught up in the weirder part of the Internet, but we’ll reserve our judgement until they provide more technical details of what they propose.
The idea of a tritium power cell is pretty straightforward: stick enough of the tiny glowing tubes to a photovoltaic panel and your DIY “nuclear battery” will generate energy for the next decade or so. Only problem is that the power produced, measured in a few microwatts, isn’t enough to do much with. But as [Ian Charnas] demonstrates in his latest video, you can eke some real-world use out of such a cell by storing up its power over a long enough period.
As with previous projects we’ve seen, [Ian] builds his cell by sandwiching an array of keychain-sized tritium tubes between two solar panels. Isolated from any outside light, power produced by the panels is the result of the weak green glow given off by the tube’s phosphorus coating as it gets bombarded with electrons. The panels are then used to charge a bank of thin-film solid state batteries, which are notable for their exceptionally low self-discharge rate.
Some quick math told [Ian] that a week of charging should build up enough of a charge to power a knock-off handheld Tetris game for about 10 minutes. Unfortunately, after waiting the prescribed amount of time, he got only a few seconds of runtime out of his hacked together power source.
His best guess is that he got a bad batch of thin-film batteries, but since he could no longer find the exact part number he used originally, he had to design a whole new PCB for the second attempt. After waiting two long months to switch the game on this time, he was able to play for nearly an hour before his homebrew nuclear energy source was depleted.
We wouldn’t consider this terribly practical from a gaming standpoint, but like the solar harvesting handheld game we covered last year, it’s an interesting demonstration of how even a minuscule amount of power can be put to work for intermittent applications. Here it’s a short bout of wonky Tetris, but the concept could just as easily be applied to an off-grid sensor.
The past year has been quite a ride for everyone on Earth. But you never know which day is going to be your last, so you might as well live a little, eh? This clock doesn’t actually know when you’ll kick off, either. But just for fun, it predicts the number of years remaining until you go to that hackerspace in the sky by hazarding a guess that’s based on your current age and the latest life expectancy tables. Don’t like the outcome? It’s completely randomized, so just push the button and get a set of numbers: the age you might die, and the percentage of life elapsed and remaining.
We love the design of this calculated doom clock, and it’s quite simple inside — an Arduino Pro Mini outputs the graph on an 2.9″ e-paper display, and both are powered with a 5.5 V solar panel. Just suction cup that puppy to the window and you’ll get automatic updates about your impending demise on sunny days, and none on cloudy days.