flux

36 Articles

Visual Magnetic Fields

February 25, 2019 by 18 Comments

If you need help visualizing magnetic fields, these slow-motion video captures should educate or captivate you. Flux lines are difficult to describe in words, because magnet shape and strength play a part. It might thus be difficult to visualize what is happening with a conical magnet, for a person used to a bar magnet. We should advise you before you watch the video below the break, if you are repelled by the sight of magnetite sand clogging a bare magnet then flying on the floor, this is your only warning.

The technique and equipment are simple and shown in the video. A layer of black sand is spread on a piece of tense plastic to make something like a dirty trampoline, and a neodymium magnet is dropped in the middle. The bouncing action launches the sand and magnet simultaneously so they are hanging in the air and the particles can move with little more than air resistance.

These videos were all taken with a single camera and a single magnet. Multiple cameras would yield 3D visuals, and the intertwining fields of multiple magnets can be beautiful. Perhaps a helix of spherical magnets? What do you have lying around the hosue? In a twist, we can use magnets to simulate gas atoms and trick them into performing unusual feats.

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Cheap Muon Detectors Go Aloft On High-Altitude Balloon Mission

January 15, 2019 by 15 Comments

There’s something compelling about high-altitude ballooning. For not very much money, you can release a helium-filled bag and let it carry a small payload aloft, and with any luck graze the edge of space. But once you retrieve your payload package – if you ever do – and look at the pretty pictures, you’ll probably be looking for the next challenge. In that case, adding a little science with this high-altitude muon detector might be a good mission for your next flight.

[Jeremy and Jason Cope] took their inspiration for their HAB mission from our coverage of a cheap muon detector intended exactly for this kind of citizen science. Muons constantly rain down upon the Earth from space with the atmosphere absorbing some of them, so the detection rate should increase with altitude. [The Cope brothers] flew two of the detectors, to do coincidence counting to distinguish muons from background radiation, along with the usual suite of gear, like a GPS tracker and their 2016 Hackaday prize entry flight data recorder for HABs.

The payload went upstairs on a leaky balloon starting from upstate New York and covered 364 miles (586 km) while managing to get to 62,000 feet (19,000 meters) over a five-hour trip. The [Copes] recovered their package in Maine with the help of a professional tree-climber, and their data showed the expected increase in muon flux with altitude. The GoPro died early in the flight, but the surviving footage makes a nice video of the trip.

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Soldering Like It’s 205 BC

September 18, 2018 by 43 Comments

Did you ever stop to think how unlikely the discovery of soldering is? It’s hard to imagine what sequence of events led to it; after all, metals heated to just the right temperature while applying an alloy of lead and tin in the right proportions in the presence of a proper fluxing agent doesn’t seem like something that would happen by accident.

Luckily, [Chris] at Clickspring is currently in the business of recreating the tools and technologies that would have been used in ancient times, and he’s made a wonderful video on precision soft soldering the old-fashioned way. The video below is part of a side series he’s been working on while he builds a replica of the Antikythera mechanism, that curious analog astronomical computer of antiquity. Many parts in the mechanism were soldered, and [Chris] explores plausible methods using tools and materials known to have been available at the time the mechanism was constructed (reported by different historians as any time between 205 BC and 70 BC or so). His irons are forged copper blocks, his heat source is a charcoal fire, and his solder is a 60:40 mix of lead and tin, just as we use today. He vividly demonstrates how important both surface prep and flux are, and shows both active and passive fluxes. He settled on rosin for the final joints, which turned out silky smooth and perfect; we suspect it took quite a bit of practice to get the technique down, but as always, [Chris] makes it look easy.

If you’d like to dig a bit deeper into modern techniques, we’ve covered the physics of solder and fluxes in some depth. And if you need more of those sweet, sweet Clickspring videos, we’ve got you covered there as well.

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IBM PCjr Revived By An ATX Power Supply And Many False Starts

August 10, 2018 by 26 Comments

The IBM PCjr was a computer only the marketing geniuses of a multi-billion dollar corporation could love. On the face of it, it seemed like a great idea – a machine for the home market, meant to complement the “big boy” IBM PC in the office and compete against the likes of Apple and Commodore. What it ended up as was a universally hated, only partially PC-compatible machine which sold a mere half-million units before being mercifully killed off.

That doesn’t mean retrocomputing fans don’t still snap up the remaining machines, of course. [AkBKukU] scored a PCjr from a thrift store, but without the original external brick power supply. An eBay replacement for the 18-VAC supply would have cost more than the computer, so [AkBKukU] adapted a standard ATX power supply to run the PCjr. It looked as if it would be an easy job, since the external brick plugs into a power supply card inside the case which slots into the motherboard with a card-edge connector. Just etch up a PCB, solder on an ATX Molex connector, and plug it in, right? Well, not quite. The comedy of errors that ensued, from the backward PCB to the mysteriously conductive flux, nearly landed this one in the “Fail of the Week” bin. But [AkBKukU] soldiered on, and his hand-scratched adapter eventually prevailed; the video below tells the whole sordid tale, which thankfully ended with the sound of the machine booting from the 5-1/4″-floppy drive.

In the end, we’ve got to applaud [AkBKukU] for taking on the care and feeding of a machine so unloved as to be mentioned only a handful of times even on these pages. One of those articles marks the 25th anniversary of the PCjr, and lays out some of the reasons for its rapid disappearance from the market.

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Flux Capacitor Prop With Christopher Lloyd’s Stamp Of Approval

April 5, 2017 by 20 Comments

We love our props here at Hackaday, and whenever we come across a piece from the Back To The Future fandom, it’s hard to resist showcasing it. In this case, [Xyster101] is showing of his build of Doc Brown’s Flux Capacitor.

[Xyster101] opted for a plywood case — much more economical than the $125 it would have cost him for a proper electrical box. Inside, there’s some clever workarounds to make this look as close as possible to the original. Acrylic rods and spheres were shaped and glued together to replicate the trinity of glass tubes, 3/4″ plywood cut by a hole saw mimicked the solenoids, steel rods were sanded down for the trio of points in the centre of the device and the spark plug wires and banana connectors aren’t functional, but complete the look. Including paint, soldering and copious use of hot glue to hold everything in place, the build phase took about thirty hours.

The LEDs have multiple modes, controlled by DIP switches hidden under a pipe on the side of the box. There’s also motion sensor on the bottom of the case that triggers the LEDs to flicker when you walk by. And, if you want to take your time-travel to-go, there’s a nine volt plug to let you show it off wherever — or whenever — you’re traveling to. Check out the build video after the break.

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What The Flux: How Does Solder Work Anyway?

February 23, 2017 by 102 Comments

I’ve been soldering for a long time, and I take pride in my abilities. I won’t say that I’m the best solder-slinger around, but I’m pretty good at this essential shop skill — at least for through-hole and “traditional” soldering; I haven’t had much practice at SMD stuff yet. I’m confident that I could make a good, strong, stable joint that’s both electrically and mechanically sound in just about any kind of wire or conductor.

But like some many of us, I learned soldering as a practical skill; put solder and iron together, observe results, repeat the stuff that works and avoid the stuff that doesn’t. Seems like adding a little inside information might help me improve my skills, so I set about learning what’s going on mechanically and chemically inside a solder joint.

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Iron Tips: Soldering Headphones And Enamel Wire

November 22, 2016 by 80 Comments

We’ve all had that treasured pair of headphones fail us. One moment we’re jamming out to our favorite song, then, betrayal. The right ear goes out. No wait. It’s back. No, damn, it’s gone. It works for a while and then no jiggling of the wire will bring it back. So we think to ourselves, we’ve soldered before. This is nothing. We’ll just splice the wire together.

So we open it up only to be faced with the worst imaginable configuration: little strands of copper enamel wire intertwined with nylon for some reason. How does a mortal solder this? First you try to untwine the nylon from the strands. It kind of works, but now the strands are all mangled and weird. Huh. Okay. well, you kind of twist them together and give a go at soldering. No dice. Next comes sandpaper, torches, and all sorts of work-a-rounds. None of them seem to work. The best you manage is sound in one ear. It’s time to give up.

Soldering this stuff is actually pretty easy. It just takes a bit of knowledge about how assembly line workers do it. Let’s take a look.

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