Visualizing Energy Fields With A Neon Bulb Array

March 4, 2020 by 20 Comments

Everyone knows that one of the coolest things to do with a Tesla coil is to light up neon or fluorescent tubes at a distance. It’s an easy and very visual way to conceptualize how much energy is being pumped out, making it a favorite trick at science museums all over the world. But what would it look like if you took that same concept and increased the resolution? Replace that single large tube with an array of smaller ones. That’s exactly what [Jay Bowles] did in his latest video, and the results are impressive to say the least.

From a hardware standpoint, it doesn’t get much simpler. [Jay] knew from experience that if you bring a small neon indicator close to a Tesla coil, it will start to glow when approximately 80 volts is going through it. The higher the voltage, the brighter the glow. So he took 100 of these little neon bulbs and arranged them in a 10×10 grid on a piece of perfboard. There’s nothing fancy around the backside either, just all the legs wired up in parallel.

When [Jay] brings the device close to his various high-voltage toys, the neon bulbs still glow like they did before. But the trick is, they don’t all glow at the same brightness or time. As the panel is moved around, the user can actually see the shape and relative strength of the field by looking at the “picture” created by the neon bulbs.

The device isn’t just a cool visual either, it has legitimate applications. In the video, [Jay] explains how it allowed him to observe an anomalous energy field that collapsed when he touched the base of his recently completed Tesla coil; an indication that there was a grounding issue. He’s also observed some dead spots while using what he’s come to call his “High-Voltage Lite-Bright” and is interested in hearing possible explanations for what he’s seeing.

We’ve been fans of [Jay] and the impressively produced videos he makes about his high-voltage projects for years now, and we’re always excited when he’s got something new. Most hardware hackers start getting sweaty palms once the meter starts indicating more than about 24 VDC, so we’ve got a lot of respect for anyone who can build this kind of hardware and effectively communicate how it works to others.

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Raising The Titanic’s Radio Room

March 4, 2020 by 149 Comments

For some reason, of all the ships that have sailed the oceans, it’s the unlucky ones that capture our imagination. Few ships have been as unlucky as the RMS Titanic, sinking as she did on the night of April 15, 1912 after raking across an iceberg on her maiden voyage, and no ship has grabbed as much popular attention as she has.

During her brief life, Titanic was not only the most elegant ship afloat but also the most technologically advanced. She boasted the latest in propulsion and navigation technology and an innovation that had only recently available: a Marconi wireless room, used both for ship-to-shore and ship-to-ship communications.

The radio room of the Titanic landed on the ocean floor with the bow section of the great vessel. The 2.5-mile slow-motion free fall destroyed the structure of the room, but the gear survived relatively intact. And now, more than a century later, there’s an effort afoot to salvage that gear, with an eye toward perhaps restoring it to working condition. It’s a controversial plan, of course, but it is technologically intriguing, and it’s worth taking a look at what’s down there and why we should even bother after all these years.

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Gorgeous Clock, And Not A Line Of Code In Sight

March 4, 2020 by 41 Comments

[Harry] dropped us a note to let us know about his completed CMOS clock project, and we’re delighted that he did because it’s gorgeous. It’s a digital clock satisfyingly assembled entirely from hardware logic, without a single line of code. There are three main parts to this kind of digital clock: ensuring a stable time base, allowing for setting the time, and turning the counter outputs into a numerical display.

Keeping accurate time is done with a 32.768 kHz crystal, and using CMOS logic to divide that down to a 1 Hz square wave. From there, keeping track of hours and minutes and seconds is mostly a matter of having counters reset and carry at the appropriate times. Setting the clock is done by diverting the 1 Hz signal so that it directly increments either the hours or minutes counter. The counter values are always shown “live” on six 7-segment displays, which makes it all human-readable.

The whole thing is tastefully enclosed in a glass dome which looks great, but [Harry] helpfully warns prospective makers that such things have an unfortunate side effect of being a fingerprint magnet. Schematics and design files are provided for those who want a closer look.

This clock uses a crystal and divider, but there’s another method for keeping accurate time and that’s to base it off the alternating current frequency of power from the grid. Not a bad method, albeit one that depends on being plugged into the wall.

Write Once, Run Everywhere: Cross-Platform Programming Done Right

March 4, 2020 by 58 Comments

One of the goals of programming languages back in the 1950s was to create a way to write assembly language concepts in an abstract, high-level manner. This would allow the same code to be used across the wildly different system architectures of that era and subsequent decades, requiring only a translator unit (compiler) that would transform the source code into the machine instructions for the target architecture.

Other languages, like BASIC, would use a runtime that provided an even more abstract view of the underlying hardware, yet at the cost of a lot of performance. Although the era of 8-bit home computers is long behind us, the topic of cross-platform development is still highly relevant today, whether one talks about desktop, embedded or server development. Or all of them at the same time.

Let’s take a look at the cross-platform landscape today, shall we?

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Dog-Harnessing The Power Of Walkie Talkies

March 4, 2020 by 12 Comments

[javier.borquez] likes to take his dog to the hang out at the dog park around dusk. But once the sun goes down and [Rusio]’s off the leash, running amok with the other dogs, it’s almost impossible to keep track of him.

Sure, there are probably glow-in-the-dark or lighted collars out there, but if you go commercial, chances are good that someone else’s dog will be wearing the same thing. Besides, what’s the fun in buying something that you can do a better job making yourself? With this dog distance indicator harness, you don’t even have to program anything. Instead, it uses a cheap pair of modified walkie talkies to show green LEDs on the harness while the dog is in range, and red when it isn’t.

Although [javier]’s pupper is the best pupper yes he is, [Rusio] can’t be expected to hold down the button and bark his location. His walkie talkie uses a 555-based frequency generator and a glued-down button to speak at 1 kHz.

Over in [javier]’s walkie, there’s a resistor in place of the speaker to keep the talkie parts working. There’s also a half-wave bridge rectifier that charges a capacitor when [Rusio] is within range, and a resistor that drains it when he’s outside the 6-8 meter range. The rectifier’s output goes to a second 555 set up as a Schmitt trigger, which tells a transistor to turn the red LEDs on instead.

If you got stuck on the idea of hearing your dog talk to you over distances, here’s a Bluetooth Babelfish collar.

Wire Wrapping Skills Put To Use For Sign Making

March 4, 2020 by 20 Comments

We don’t see many wire wrapped circuits these days, and you could be forgiven for thinking it was nearly a lost art at this point. But that doesn’t mean the technique can’t be applied elsewhere. [MiHu-Works] recently wrote in to share a sign they recently made for a client’s restaurant that looks an awful lot like the back panel of a homebrew computer to us.

Before you get a chance to scroll down and complain about it in the comments, we admit this one is fairly deep into the crafts side of the spectrum. But it’s also a gorgeous piece that we’d be happy to hang up in the hackerspace, so we don’t care. There might not be any angry pixies zipping around through all that lovingly wrapped copper wire, but it certainly feels like you’re looking at the internals of some complex machine.

To make it, [MiHu-Works] first printed out the lettering on paper and put it on the wood to serve as a guide. Roofing nails were then driven into the wood to create the outline of the text. A simple tool made from a forked piece of wood was placed under the head of each nail as it was hammered in to make sure the depth was consistent. It also made sure there was adequate room underneath to wrap the copper wires through them. Then it was time for the wrapping…so much wrapping. (Who is going to come through with the robot to do this?)

A few years back we asked the Hackaday readers if they thought the days of wire wrapped circuits were over. It generated a lot of discussion and interesting ideas, but looking at projects like this, perhaps we were asking the wrong question.

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Stop ‘n Go DUPLO

March 3, 2020 by 8 Comments

[beshur]’s 2-year-old is obsessed with transportation, so he lifted a few DUPLO blocks from the bin and made this toy traffic light as a birthday present. Hey, might as well get him used to the realities of traffic, right? It also makes for a good early hacker lesson: why buy something when you can make it yourself?

The traffic pattern is determined by an Arduino Nano V3 situated inside the carved-out rear block. There’s a push button on the side in case there’s a spill and the lights need to go blinking red until the issue is dealt with. Instead of trying to solder everything in situ and risk melting the plastic, [beshur] dead-bugged the LEDs and resistors to the Nano with a helping hands and then worked everything into the case. The 5mm LEDs fit perfectly into the drilled-out posts of a second block and produce a nice, soft glow. Proceed with caution and check it out after the break.

Of course, plastic building blocks can do real work, too. This LEGO chocolate pantograph is pretty sweet.

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