If you have a signal that passes through a capacitor or transformer, you will lose the DC portion of the signal. What do you do? If you need it, you can restore the DC bias using various techniques, as [Sam Ben-Yaakov] shows in a recent video.
These types of circuits were common in analog TVs, and, in fact, [Sam] shows the schematic of a TV to explain the need for the DC level. In that case, a vacuum tube diode does the work, but a solid state one will do the same job.
Engineered stone, also known as artificial stone or composite stone, has become a popular material in the construction and design industries due to its aesthetic appeal and durability. It’s become the go-to solution for benchtops in particular, with modern kitchens and bathrooms heavily featuring engineered stone in this way.
However, this seemingly innocuous material harbors a dark side, posing significant health risks to workers involved in its manufacturing and installation. The hazards associated with engineered stone have gone unnoticed for some time, but the toll is adding up, and calls for action grow louder. Let’s examine why engineered stone is so harmful, and explore the measures being taken across the world to curtail or even ban its use.
Continue reading “Australia Bans Engineered Stone, Workers Elsewhere Demand The Same”
If you are making certain precision measurements, you know you need to terminate the connections with the right impedance, normally 50 ohms. Proper termination minimizes reflections on the line which can disturb measurements. Some instruments already have 50 ohm terminations, at least optionally. If not, you usually use little connector shells with the right resistor inside. [Joe Smith] decided to see if he could improve on the normal terminations using circuit simulation techniques. You can see a video of the work below.
In the process of testing, he also needs a resistive splitter, and, just like with the terminators, he shows you what’s going on inside. It was easy to compare since he had a scope that could independently set channels to have a 50-ohm termination or a 1 megaohm termination.
When you design your first homebrew CPU, you probably are happy if it works and you don’t worry as much about performance. But, eventually, you’ll start trying to think about how to make things run faster. For a single CPU, the standard strategy is to execute multiple instructions at the same time. This is feasible because you can do different parts of the instructions at the same time. But like most solutions, this one comes with a new set of problems. Japanese researchers are proposing a novel way to work around some of those problems in a recent paper about a technique they call Clockhands.
Suppose you have a set of instructions like this:
LOAD A, 10
LOAD B, 20
SUB A,B
LOAD B, 30
JMPZ DONE
INC B
If you do these one at a time, you have no problem. But if you try to execute them all together, there are a variety of problems. First, the subtract has to wait for A and B to have the proper values in them. Also, the INC B may or may not execute, and unless we know the values of A and B ahead of time (which, of course, we do here), we can’t tell until run time. But the biggest problem is the subtract has to use B before B contains 30, and the increment has to use it afterward. If everything is running together, it can be hard to keep straight.
We all have good intentions when starting a new project, but then again, we all know where those lead. Such is the case with [RealCorebb]’s BBAir project, a completely transparent air bubble display. Although the plan was to spend about three months on it, the months slowly added up to a full year of tinkering.
It all started when [RealCorebb] made a subscriber counter using Minecraft campfire smoke to display the digits. Someone suggested using air to implement the next iteration, and for [RealCorebb], it was challenge accepted. After considering a syringe for each channel, a separate pump, or one pump and many solenoids, [RealCorebb] settled on solenoids to push air, and designed a PCB to reduce the amount of wire spaghetti.
Once [RealCorebb] created an acrylic enclosure and wired everything up, it was time to test it out. Everything worked, except that air was leaking from somewhere, which turned out to be the way the solenoids were installed. Then, of course, it was time to don sunglasses and write the code. We still don’t know if [RealCorebb] settled on water, glycerine, or silicone oil, but the end result is quite nice, and we’re betting on glycerine. Be sure to check out the build video after the break, which has English subtitles.
Although we’ve seen our share of bubble displays before, we often discuss bubble LEDs displays like this one.
We think of crystals as the gold standard of frequency generation. However, if you want real precision, you need something either better than a crystal or something that will correct for tiny errors — often called disciplining the oscillator. [W3AXL] picked up a rubidium reference oscillator on eBay at a low cost, and he shows us how it works in the video you can see below. He started with a GPS-disciplined oscillator he had built earlier and planned to convert it to discipline from the rubidium clock.
The connector looks like a D-shell connector superficially, but it has a coax connector in addition to the usual pins. The device did work on initial powerup, and using a lissajous pattern to compare the existing oscillator with the new device worked well.
[Theo Jansen] is famous for his giant walking Strandbeest creations. They’re elegant, impressive, and powered by nature, and their walking mechanism is a thing of beauty. If you’ve ever wanted to build your own, [Antonio Garcia] has just the guide to get you started on the smaller scale.
Unlike so many other builds today, this one features some good old fashioned craft techniques. The build uses popsicle sticks for the legs, what appear to be toothpicks for the joints, and a cardboard box for the main body. A small brushed DC motor is used for propulsion to keep things easy, which runs off a few AA batteries. It’s a gearmotor, which gives it plenty of torque to propel the walking mechanism without undue strain.
It may not be powered by nature, and it may not be taller than most humans, but it’s still got an appealing gait and it still inspires us with its design. If you want to learn more, go ahead and take a gander at [Theo Jansen’s] own designs and see what you can pick up. Video after the break.
Continue reading “Build A Strandbeest Replica Of Your Very Own”
