An Arduino-Free Automatic Alcohol Administrator

April 5, 2020 by Kristina Panos 30 Comments

With all the hands-free dispenser designs cropping up out there, the maker world could potentially be headed for an Arduino shortage. We say that in jest, but it’s far too easy to use an Arduino to prototype a design and then just leave it there doing all the work, even if you know going in that it’s overkill.

[ASCAS] took up the challenge and built a cheap and simple dispenser that relies on recycled parts and essential electronics. It uses an IR proximity sensor module to detect dirty digits, and a small submersible pump to push isopropyl alcohol, sanitizer, or soap up to your hovering hand. The power comes from a sacrificial USB cable and is switched through a transistor, so it could be plugged into the wall or a portable power pack.

We admire the amount of reuse in this project, especially the nozzle-narrowing ballpoint pen piece. Be sure to check out the build video after the break.

Hopefully, you’re all still washing your hands for the prescribed 20 seconds. If you’re starting to slip, why not build a digital hourglass and watch the pixels disappear?

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Compact Slayer Exciter For Your High Voltage Needs

March 21, 2020 by Tom Nardi 8 Comments

Tesla coils are incredible pieces of hardware, but they can be tricky to build. Between the spark gap, capacitors, and finely tuned coils, it’s not exactly a beginners project. Luckily, there’s hope for anyone looking for a less complex way to shoot some sparks: the Slayer Exciter. This device can be thought of as the little cousin to the Tesla coil, and can be used for many of the same high voltage experiments while being far easier to assemble.

Now [Jay Bowles] is obviously no stranger to building his own Tesla coils, but since so many of his fans wanted to see his take on this less complex option, he recently built his own Slayer Exciter. After putting on a few of his own unique touches, the end result looks very promising. It might not be able to throw sparks as far as some of the other creations featured on his YouTube channel, but it’s still impressive for something so simple.

[Jay] uses two transistors in parallel for reliability

When we say simple, we mean it. Building a bare-bones Slayer Exciter takes only takes five components: the two coils, a transistor, a diode, and a resistor. For this build, power is provided by a trio of rechargeable 9 V batteries in the base of the unit which can be easily swapped out as needed.

In the video, [Jay] does a great job explaining and illustrating how this basic circuit creates exceptionally high frequency energy. In fact, the frequency is so high that the human ear can’t hear it; unfortunate news for fans of the Tesla coil’s characteristic buzz.

Generally speaking Slayer Exciters would have the same sort of vertical coils that you’d see used on a traditional Tesla coil, but in this case, [Jay] has swapped that out for a pancake coil held in the upper level of the device. This makes for a very compact unit that would be perfect for your desk, if it wasn’t for the fact that the arcs produced by this gadget are hot enough to instantly vaporize human skin. Just something to keep in mind.

We’ve seen Slayer builds in the past, but none as well designed as this one. Incidentally, if you’re wondering about the array of neon indicator lights that [Jay] uses to visualize the electrical field, we covered that project as well.

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Powering Neon With A Joule Thief

March 14, 2020 by Bryan Cockfield 10 Comments

Joule thief are small, fun circuits which exploit a few characteristics of electronics and LEDs in order to “steal” virtually all of the energy stored in a battery. They can operate at incredibly small voltages and are fairly simple to make. With a few modifications to this basic circuit it’s possible to drive other things than an LED, though, like this joule thief that lights up a neon bulb.

The circuit from [suedbunker] aka [fuselage] is based on a pin from the Chaos Communication Camp which had a standard LED. To get a neon light to illuminate a few modifications to the standard joule thief are needed.

First, the windings have to be changed from 10:10 to 10:80 to increase the voltage across the bulb. Second, a transistor with slightly different characteristics was used than the original design. The capacitor was also replaced with a larger one.

While it might seem simple, the physics of how a joule thief works are anything but, and modifying the delicate circuit to work with something other than an LED is commendable. It also has a steampunk vibe which is a cool look even in projects that don’t involve steam at all.

New Part Day: The Bizen Transistor

November 23, 2019 by Jenny List 64 Comments

If we had a dollar for every exciting new device that’s promised to change everything but we never hear of beyond the initial hoopla, we’d own our own private islands in the sun from the beaches of which we’d pick out Hackaday stories with diamond-encrusted keyboards. The electronic engineering press likes to talk about new developments, and research scientists like a bit of publicity to help them win their next grant.

The Bizen transistor however sounds as though it might have some promise. It’s a novel device which resembles a bipolar transistor in which the junctions exhibit Zener diode-like properties, and in which the mechanism is through quantum tunneling rather than more conventional means. If this wasn’t enough, its construction is significantly simpler than conventional semiconductors, requiring many fewer support components to make a logic gate than traditional CMOS or TTL, and requires only eight mask steps to manufacture. This means that lead times are slashed, and that the cost of producing devices is much reduced.

The device’s originator has partnered with a semiconductor fab house to offer a service in which custom logic chips can be produced using the new devices in a series of standard building blocks. This is likely to be only of academic interest to the hacker at the moment, however the prospect of this cost reducing as the technology matures does show promise of reaching the means of some more well-funded hacker projects. It will be a while before we can order a chip with the same ease as a PCB, but this makes that prospect seem just a little bit closer.

Thanks [Ken Boak] for the tip.

DIY Clapper Lets You Pick Your Components

October 6, 2019 by Al Williams 4 Comments

One thing that always means the end of the year is close is the reappearance of TV ads for “The Clapper.” After all, who needs home automation when you can clap on and clap off? While we’re partial to our usual home automation solutions, [Utsource123] shows us that building a clapper can be a fun and easy project using several similar circuits. One with a few transistors and another one with a 555 because, after all, what can’t a 555 do?

Of course, these circuits usually have a microphone. We were trying to think of how you could make a sound-sensitive element out of common parts. After all, you don’t care about the fidelity of the microphone pickup, just that it hears a loud noise. The circuits are about what you’d expect. The transistor version uses one to amplify the microphone and another to switch on the LED. You’d need a bit more to trigger a relay. The 555 uses an even simpler preamp transistor as a trigger.

While we aren’t bowled over with the idea of a clapper, we imagine these circuits aren’t far removed from the ones you buy in stores. For about $16 you also get enough switching to handle a simple AC load, though. Maybe Alexa and Google should allow making clapping a wake up word?

This is sure simpler than the last clapper clone we saw. Then there’s the deluxe DIY version.

Building Video Pong With Discrete Components

September 17, 2019 by Lewin Day 19 Comments

Pong is a classic from the very dawn of the video game era. Recreating it remains a popular exercise for those new to coding. However, its simple logic makes this game particularly suited to an all-hardware build; something which [Glen] tackles with aplomb.

Not content to take the easy way out, [Glen] went for a particularly hardcore method of construction. The game uses absolutely zero integrated circuits in its construction. Instead, it relies upon the services of 431 bipolar transistors, 6 JFETs and 826 diodes. Everything is laced together on protoboard, connected with a neatly organised nest of colored wires. Schematics are available for the curious.

It’s a full featured build, too. Video output is in color, scores are displayed at the top of the screen, and there’s even stereo panning for the sound effects. It just goes to show what some humble components can do when put to work in the right way. We’ve seen some of [Glen]’s work before too, for example in this op-amp bouncing ball device. Video after the break.

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Hackaday Links: August 25, 2019

August 25, 2019 by Dan Maloney 7 Comments

Doesn’t the Z-axis on 3D-printers seem a little – underused? I mean, all it does is creep up a fraction of a millimeter as the printer works through each slice. It would be nice if it could work with the other two axes and actually do something interesting. Which is exactly what’s happening in the nonplanar 3D-printing methods being explored at the University of Hamburg. Printing proceeds normally up until the end, when some modifications to Slic3r allow smooth toolpaths to fill in the stairsteps and produce a smooth(er) finish. It obviously won’t work for all prints or printers, but it’s nice to see the Z-axis finally pulling its weight.

If you want to know how something breaks, best to talk to someone who looks inside broken stuff for a living. [Roger Cicala] from LensRentals.com spends a lot of time doing just that, and he has come to some interesting conclusions about how electronics gear breaks. For his money, the prime culprit in camera and lens breakdowns is side-mounted buttons and jacks. The reason why is obvious once you think about it: components mounted perpendicular to the force needed to operate them are subject to a torque. That’s a problem when the only thing holding the component to the board is a few SMD solder pads. He covers some other interesting failure modes, too, and the whole article is worth a read to learn how not to design a robust product.

In the seemingly neverending quest to build the world’s worst Bitcoin mining rig, behold the 8BitCoin. It uses the 6502 processor in an Apple ][ to perform the necessary hashes, and it took a bit of doing to port the 32-bit SHA256 routines to an 8-bit platform. But therein lies the hack. But what about performance? Something something heat death of the universe…

Contributing Editor [Tom Nardi] dropped a tip about a new online magazine for people like us. Dubbed Paged Out!, the online quarterly ‘zine is a collection of contributed stories from hackers, programmers, retrocomputing buffs, and pretty much anyone with something to say. Each article is one page and is formatted however the author wants to, which leads to some interesting layouts. You can check out the current issue here; they’re still looking for a bunch of articles for the next issue, so maybe consider writing up something for them – after you put it on Hackaday.io, of course.

Tipline stalwart [Qes] let us know about an interesting development in semiconductor manufacturing. Rather than concentrating on making transistors smaller, a team at Tufts University is making transistors from threads. Not threads of silicon, or quantum threads, or threads as a metaphor for something small and high-tech. Actual threads, like for sewing. Of course, there’s plenty more involved, like carbon nanotubes — hey, it was either that or graphene, right? — gold wires, and something called an ionogel that holds the whole thing together in a blob of electrolyte. The idea is to remove all rigid components and make truly flexible circuits. The possibilities for wearable sensors could be endless.

And finally, here’s a neat design for an ergonomic utility knife. It’s from our friend [Eric Strebel], an industrial designer who has been teaching us all a lot about his field through his YouTube channel. This knife is a minimalist affair, designed for those times when you need more than an X-Acto but a full utility knife is prohibitively bulky. [Eric’s] design is a simple 3D-printed clamshell that holds a standard utility knife blade firmly while providing good grip thanks to thoughtfully positioned finger depressions. We always get a kick out of watching [Eric] design little widgets like these; there’s a lot to learn from watching his design process.

Thanks to [JRD] and [mgsouth] for tips.