If you watch YouTube long enough, it seems like going “off the grid” is all the rage these days. But what if the thing that goes off the grid is the grid itself? In the video below the break, [Grady] with Practical Engineering explores the question: How do you restart an entire power grid after it’s gone offline? It’s a brilliantly simple deep dive into what it takes to restore power to large amounts of customers without causing major damage to not just the grid, but the power generators themselves.
The hackers among us who’ve dealt with automotive alternators know it must be excited in order to generate electricity. What does that even mean, and how does it affect the grid? Simply put, it takes power to make power. For example, old heavy equipment had what they called pony motors — a small easy to start engine that’s sole purpose was to start a much larger engine. Aircraft have auxiliary power units (APUs) for the same purpose. What do power grids have? You’ll have to watch the video to find out.
Once at least two power generators are online, grid operators can just flip the switch and start feeding power to customers, right? Not quite. [Grady] once again uses a clever test jig and an oscilloscope to show the damage that can occur if things aren’t done just right. It’s a fascinating video well worth watching.
We all know that using 3D printing filament with exotic filament that has metal or carbon fibers in it will tend to wear standard nozzles. That’s why many people who work with filaments like that use something other than conventional brass nozzles like hardened steel. There are even nozzles that have a ruby or diamond surfaces to prevent wear. However, [Slant 3D] asserts something we didn’t know: white filament may be wearing your nozzle, too. You can see his argument in the video below.
The reason? According to Slant 3D, the problem is the colorant added to make it white: titanium dioxide. Unlike some colorants, the titanium dioxide colorant has a large grain size. The video claims that the hard titanium material has a particle size of about 200 nm, which is much larger than, say, carbon black, which is about 20 times smaller.
These devices have a superficially very simple circuit that makes extensive use of PCB layout for creating microwave inductors, capacitors, and tuned circuits. There’s a FET oscillator and a diode mixer, and a dielectric resonator coupling the output and input inductors of the FET. This component provides the frequency stability, but its exact frequency depends on what lies within its electric field. Thus the screening can does more than screening, and has a significant effect on the frequency and stability of the oscillator.
The higher quality HB100s have a small tuning screw in the top of the can which in turn adjusts the frequency. This should be tweaked in the factory onto the correct point, but is frequently absent in the cheaper examples. In this case he has a pile of modules, and while surprisingly some are pretty close there are outliers that lie a significant distance away.
If you use an HB100 then the chances are nobody will ever bother you if it’s off-frequency, as its power output is tiny. But it’s worth knowing about their inner workings and also how to adjust them should you ever need to. Meanwhile if you’re interested in Doppler radar, here’s how to design one for a lower frequency.
The videos from [styropyro] are always amusing and informative. However, ironically for him, he is alarmed that many green laser pointers are more powerful than they are supposed to be. Sure, you often want a powerful laser, but if you think a laser is safe and it isn’t, you could… well… put an eye out. See the video below to see what [styropyro] claims is the brightest laser pointer in the world.
The key is a possibly gray market very large green laser array. It appears to have at least 24 lasers and some pretty serious lenses. He tested the array first with a power supply and it looked like something out of a bad science fiction movie, even at reduced power.
Most modern computer games have a clearly-defined end, but many classics like Pac-man and Duck Hunt can go on indefinitely, limited only by technical constraints such as memory size. One would think that the classic electronic memory game Simon should fall into that category too, but with most humans struggling even to reach level 20 it’s hard to be sure. [Michael Schubart] was determined to find out if there was in fact an end to the latest incarnation of Simon and built a robot to help him in his quest.
The Simon Air, as the newest version is known, uses motion sensors to detect hand movements, enabling no-touch gameplay. [Michael] therefore made a system with servo-actuated silicone hands that slap the motion sensors. The tone sequence generated by the game is detected by light-dependent resistors that sense which of the segments lights up; a Raspberry Pi keeps track of the sequence and replays it by driving the servos.
We’ve now had at least five years of USB-C ports in our devices. It’s a standard that many manufacturers and hackers can get behind. Initially, there was plenty of confusion about what we’d actually encounter out there, and manufacturer-induced aberrations have put some people off. However, USB-C is here to stay, and I’d like to show you how USB-C actually gets used out there, what you can expect out of it as a power user, and what you can get out of it as a hobbyist.
Modern devices have a set of common needs – they need a power input, or a power output, sometimes both, typically a USB2 connection, and often some higher-speed connectivity like a display output/input or USB 3. USB-C is an interface that aims to be able to take care of all of those. Everything aforementioned is optional, which is a blessing and a curse, but you can quickly learn to distinguish what to expect out of a device based on how it looks; if ever in doubt, I’d like to show you how to check.
[Joe] at BPS.space has a thing for rockets, and his latest quest is to build a rocket that will cross the Kármán Line and launch into the Final Frontier. And being the owner of a YouTube channel, he wants to have excellent on-board video that he can share. The trouble? Spinning. A spinning rocket is a stable rocket, especially as altitude increases. So how would [Joe] get stable video from a rocket spinning at several hundred degrees per second? That’s the question being addressed in the video below the break.
Rather than use processing power to stabilize video digitally, [Joe] decided to take a different approach: Cancelling out the spin with a motor, essentially making a camera-wielding reaction wheel that would stay oriented in one direction, no matter how fast the rocket itself is spinning.
Did it work? Yes… and no. The design was intended to be a proof of concept, and in that sense there was a lot of success and some excellent video was taken. But as with many proof of concept prototypes, the spinning camera module has a lot of room for improvement. [Joe] goes into some details about the changes he’ll be making for revision 2, including a different motor and some software improvements. We certainly look forward to seeing the progress!
To get a better idea of the problem that [Joe] is trying to solve, check out this 360 degree rocket cam that we featured a few years ago.