Kritik sah

When you hear the word TV, you probably think of a big LED screen, maybe even the old CRT TVs, but in either case it’s something large and fairly complicated. However, thanks to the persistence of vision, it doesn’t have to be. In this handheld-sized project from [Ancient], the Scanwheel is born, a miniature mechanical TV that uses a spinning disk and some LEDs to produce an image. The electronics of the Scanwheel are pretty straightforward. The smarts come from a Raspberry Pi Pico, an A4988 motor driver, a couple of LEDs, and a small 21-02485 stepper motor. The Raspberry Pi Pico is used to command the motor speed as well as coordinate the LEDs to turn on at the right time. The case is 3D printed; the base includes space for the various support electronics as well as some small light baffles to ensure the LEDs don’t bleed over outside their intended area. The top of the case is a disk that includes 20 small holes spaced evenly around the perimeter at varying heights, allowing light t...

Optical cavities – two mirrors arranged to reflect light multiple times between them – form the basis of lasers and certain optical filters. Since any angle between the two mirrors results in light being scattered away, parallel alignment is essential, yet difficult to maintain. Nevertheless, [Timothy Giles] managed to 3D-print and align such an optical cavity , and used it to detect minute shifts in space and wavelength. The cavity has two semi-transparent mirrors facing towards each other. One mirror is held in a 3D-printed mount, and the other is attached to the diaphragm of a speaker with a hole drilled through the center. The hole avoids the speaker coil, and allows light exiting the optical cavity through the semi-transparent mirror to appear on a paper target, which is monitored by a webcam. On the other side of the optical cavity, a laser diode coupled to a single-mode fiber shines in through the other mirror. Alignment is challenging, but the webcam makes it easier; as the m...

At a time when so-called “artificial intelligence” seems inescapable, we were encouraged to see news that Amazon will be cracking down on third-party sellers that use AI-generated images for their product listings. They won’t be prevented from using the images, but they will need to clearly indicate that they don’t represent reality and were produced via artificial means. This comes in response to a recently enacted New York law that requires the disclosure of AI in advertisements. Will this be the end of the cat sleeping bag? But it’s not quite a clear cut as it might seem on the surface, as the New York law is actually about AI-generated people rather than products. Specifically, it’s designed to make it clear when a “synthetic performer” has been used in place of a human actor. As such, it would appear that the easiest way for Amazon sellers to dodge the new rule is to simply not include any humans in their AI slop images and videos...

After previously using the fermenting of sugar to obtain ethanol fuel, [Hyperspace Pirate] figured that it’d be a waste to just blast the other half of the yeast production in the form of carbon dioxide into the air. This poses the slight problem that gaseous CO 2 is fairly bulky, while compressing it into a liquid isn’t exactly for the faint of heart. This of course means that it’s a fun challenge , involving a beach ball, vapor-compression and various compressors. Although at room temperature compressing CO 2 into a liquid requires quite extreme pressures, if you lower it to freezing temperatures it becomes quite feasible to use more typical off-the-shell compressors. In the video both oil-less and regular compressors are used, mostly because ultimately you want to get pure CO2 into the bottle, without oil or water. Here a few methods are explored, including a pre-cooler with the oil-less compressor as it cannot quite hit the same pressures. With a typical compre...

A lot has been made about the increase of automated traffic on the Internet, with the past years LLM-related crawlers having quite literally swarmed the picture here. Not only does this drive up traffic, it also increases load on web servers, whose owners find themselves faced with increased hosting costs. This recently led to The-Numbers.com going offline for a while as automated traffic was quite literally destroying their bottom line. This saga is covered by [Stephen Follows], who had a chance to talk with the founder and CEO of the site, [Bruce Nash], after the site went basically offline for a few months. Since the website both licenses data for commercial purposes as well as offering the free access on its website, there were accusations of this being a ‘rug pull’. The site was started in 1997, as a static HTML site on Geocities where [Bruce] provided box office analyses for investment purposes. Since that beginning traffic was generally polite, with human visitors...

The sport of fencing requires keeping score, just like so many other similar pastimes. When their club’s existing scoring rig broke, [jc0025] stepped up to build a scoring box of their own, using the typical tools of the maker trade. The brains of the operation is an Arduino Nano, running the venerable ATmega328P. It’s set up to drive a pair of 8×8 WS2812B addressable LED panels. It’s also hooked up to a pair of fencing socket blocks, which hook up to the lamé (jacket), weapon, and guard of each player for electronically scoring hits. The Arduino is thus programmed to respond to various conditions, lighting the LEDs in turn. For example, the tip of one player’s weapon hitting the other player’s lamé will fire a colored light, allowing the hit to be scored. Meanwhile, a tip hitting the floor will fire a white light, indicating off-target. There’s also a buzzer for sonic indication, as well. Everything is wrapped up in a tidy 3D-printed housing, w...