We don’t know why [TubeTime] decided to show off this oddball keyboard switch as a series of Twitter posts, but we were glad to see them somewhere. At first, the switch looks pretty conventional. But as the pictures reveal the insides, you’ll notice something unusual: a ferrite toroid! These switches operate as a transformer and are known as magnetic valve switches.
The switches have two sets of two pins — one set for the primary and one for the secondary of the transformer wound around the ferrite core. That transformer remains stationary, but a pair of permanent magnets move. When the key is up, the magnets are close to the core and cause the transformer to saturate, so there is little or no output at the secondary. When you depress the key, the magnet moves away from the core, allowing the signal to pass through the transformer. What that means is there is no mechanical contact, which is good for switch life. It is also important in environments where a small spark could cause an explosion. You can watch a video about a keyboard that used those switches, below.
Continue reading “Keyboard Switch Is Really A Transformer”
Cabin fever: the inability to socialize with other humans does weird things to the human brain. Then again some of us are born to stand out, and one such amazing maker, [Lee], is spending time making weird switches from basically anything.
So what would you consider weird? How about using a piece of pasta? How about using the conductivity of an empty sink? There is even an experiment with breakfast cereal, though we do not recommend it for production use. [Lee] continues to pour experiments into Twitter and recently has gotten some conductive tape. Stick some on a game joystick and you got yourself an instant switch on a switch.
These experiments prove that there is a lot you can do with the stuff you have around your house and the other end of the circuit doesn’t necessarily need to be a humble LED. You could get more interesting results with adding the likes of a microcontroller like an ATtiny. Coupling it with a DIY LED badge would be a great idea and we’d love to see what you come up with.
[Glen]’s project sounds perfectly straightforward: have a big industrial-style push button act as a one-key USB keyboard. He could have hacked something together in any number of ways, but instead he decided to create a truly elegant solution. His custom PCB mates to the factory parts perfectly, and the USB cable between the button and the computer even fits through the button enclosure’s lead hole.
It turns out that industrial push buttons have standardized components which can be assembled in an almost LEGO-like manner, with components mixed and matched to provide different switch actions, light indicators, and things of that nature. [Glen] decided to leverage this feature to make his custom PCB (the same design used in his one-key keyboard project) fit just like a factory component. With a 3D printed adapter, the PCB locks in just like any other component, and even lines up with the lead hole in the button’s enclosure for easy connecting of the USB cable.
What does [Glen] use the big button for? Currently he has two applications: one provides a simple, one-button screen lock on a Linux box running a virtual machine at his place of work. It first disengages the keyboard capture of the virtual machine, then engages the screen lock on the host. The other inserts a poop emoji into Microsoft documents. Code and PCB design files for [Glen]’s small keyboards are available on GitHub.
An outstanding number of things most people take for granted present enormous hurdles for people with physical disabilities, including interaction with computers and other digital resources. Assistive technologies such as adaptive switches allow users who cannot use conventional buttons or other input devices to interact with digital devices, and while there are commercial offerings there is still plenty of room for projects like [Cassio Batista]’s DIY Low-cost Assistive Technology Switches.
[Cassio]’s project focuses on non-contact switches, such as proximity and puff-based activations. These are economical, DIY options aimed at improving accessibility for people who are unable to physically push even specialized switches. There are existing products in this space, but cost can be a barrier and DIY options that use familiar interfaces greatly improves accessibility.
Assistive technologies that give people the tools they need to have more control over their own lives in a positive, healthy way is one of the more vibrant and positive areas of open hardware development, and it’s not always clear where the challenges lie when creating solutions. An example of this is the winner of the 2015 Hackaday Prize, the Eyedrivomatic, which allows one to interface the steering of an electric wheelchair to a gaze tracking system while permanently altering neither device; a necessity because users often do not own their hardware.
Imagine the scenario: you’re spending some quality time in the shop with your daughter, teaching her the basics while trying to get some actual work done. You’re ripping some stock on your cheap table saw when your padiwan accidentally hooks the power cord with her foot and pulls out the plug. You have a brief chat about shop safety and ask her to plug it back in. She stoops to pick up the cord and plugs it back in while her hand is on the table! Before you can stop the unfolding tragedy, the saw roars to life, scaring the hell out of everyone but thankfully doing no damage.
If that seems strangely specific it’s because it really happened, and my daughter was scared out of the shop for months by it. I’ll leave it to your imagination what was scared out of me by the event. Had I only known about no-voltage release switches, or NVRs, I might have been able to avoid that near-tragedy. [Gosforth Handyman] has a video explaining NVRs that’s worth watching by anyone who plugs in anything that can spin, cut, slice, dice, and potentially mutilate. NVRs, sometimes also called magnetic contactors, do exactly what the name implies: they switch a supply current on and off, but automatically switch to an open condition if the supply voltage fails.
Big power tools like table saws and mills should have them built in to prevent a dangerous restart condition if the supply drops, but little tools like routers and drills can still do a lot of damage if they power back up while switched on. [Gosforth] built a fail-safe power strip for his shop from a commercial NVR, and I’d say it’s a great idea that’s worth considering. Amazon has a variety of NVRs that don’t cost much, at least compared to the cost of losing a hand.
True, an NVR power strip wouldn’t have helped me with that cheap table saw of yore, but it’s still a good idea to put some NVR circuits in your shop. Trust me, it only takes a second’s inattention to turn a fun day in the shop into a well-deserved dressing down by an angry mother. Or worse.
Continue reading “Save Fingers, Save Lives With A No-Voltage Release For The Shop”
There are a lot of good reasons to think fondly of the Nintendo GameCube. Metroid Prime and Rogue Leader knocked it out of the park. The Game Boy Player was cool. There’s even something to be said for having a convenient carrying handle on a system designed for couch multiplayer. But if you ask anyone who played Nintendo’s sixth generation console what part they missed the least, it would probably be the controller. With all the visual flair of a Little Tikes playset and ergonomics designed for an octopus, it’s a controller that works well for first-party Nintendo titles and little else.
So it’s probably for the best that these Switch Joy-Cons created by [Madmorda] focus on recreating the aesthetics of the GameCube controller for Nintendo’s latest money-printing machine rather than its feel. With a surprising amount of work required to create them, these definitely count as a labor of love by someone who yearns for the days when gaming was more…cubic.
To start with, nobody makes Joy-Con cases in that signature GameCube purple so [Madmorda] had to paint them herself. The longevity of a painted controller is somewhat debatable, but the finish certainly looks fantastic right now.
For the left analog stick [Madmorda] was able to use the cap from a real GameCube controller, which fit perfectly. Apparently, Nintendo has been pretty happy with their analog stick sizing decisions for the last two decades or so. The right analog stick was another story, however, and she had to cut the shaft down to size with a Dremel to get the cap to fit.
Finally, molds were made of the original face buttons, which were then used to cast new buttons with colored resin to match the GameCube color scheme. Since the original Switch buttons don’t have indented lettering to get picked up by the mold, she had to laser etch them. This little detail goes a long way to selling the overall look.
The final result looks great, and compared to previous attempts we’ve seen to bring some of that early 2000’s Nintendo style to the Switch, this one is certainly less destructive. Check them out in action after the break!
Continue reading “Get Nostalgic With These GameCube Themed Joy-Cons”
Switches seem to be the simplest of electrical components – just two pieces of metal that can be positioned to either touch each other or not. As such it would seem that it shouldn’t matter whether a switch is used for AC or DC. While that’s an easy and understandable assumption, it can also be a dangerous one, as this demo of AC and DC switching dramatically reveals.
Using a very simple test setup, consisting of an electric heater for a load, a variac to control the voltage, and a homemade switch, [John Ward] walks us through the details of what happens when those contacts get together. With low-voltage AC, the switch contacts exhibit very little arcing, and even with the voltage cranked up all the way, little more than a brief spark can be seen on either make or break. Then [John] built a simple DC supply with a big rectifier and a couple of capacitors to smooth things out and went through the same tests. Even at a low DC voltage, the arc across the switch contacts was dramatic, particularly upon break. With the voltage cranked up to the full 240-volts of the UK mains, [John]’s switch was essentially a miniature arc welder, with predictable results as the plastic holding the contacts melted. Don your welding helmet and check out the video below.
As dramatic as the demo is, it doesn’t mean we won’t ever be seeing DC in the home. It just means that a little extra engineering is needed to make sure that all the components are up to snuff.
Continue reading “A Dramatic Demo Of AC Versus DC Switching”