Put A Smoke Detector To Some Use

While we’re certainly not denying that smoke detectors are useful, there’s a certain kind of tragedy to the fact that most of them will never realize their true purpose of detecting smoke, and alerting us to a dangerous fire. On the other hand, [Ben] really unlocks the potential hidden deep in every smoke detector with his latest project which uses the smoke-detecting parts of a smoke detector to turn on the exhaust fan over his stove.

The project didn’t start with the noble aim of realizing the hidden and underutilized quiescent nature of a smoke alarm, though. He wanted his range exhaust fan to turn on automatically when it was needed during his (and his family’s) cooking activities. The particular range has four speeds so he wired up four relays to each of the switches in the range and programmed a Particle Photon to turn them on based on readings from an MQ-2 gas-detecting sensor.

The sensor didn’t work as well as he had hoped. It was overly sensitive to some gasses like LPG which would turn the range on full blast any time he used his cooking spray. Meanwhile, it would drift and not work properly during normal cooking. He tried disabling it and using only a temperature sensor, which didn’t work well either. Finally, he got the idea to tear apart a smoke detector and use its sensor’s analog output to inform the microcontroller of the current need for an exhaust fan. Now that that’s done, [Ben] might want to add some additional safety features to his stovetop too.

Making Colored Smoke Devices, The Right Way

Pyrotechnics are fun, and, with the proper precautions taken, safe enough to play with at home (usually). While it’s typical to purchase fireworks and smoke devices off the shelf, it’s actually possible to brew these up in a properly stocked home lab. [Tech Ingredients] is here to share the techniques behind producing your own super vibrant colored smoke devices at home.

Producing colored smoke requires a slightly different tack than making a simpler white smoke device. Colored smokes use dyes that are temperature sensitive, and thus the reaction temperature must be controlled carefully. This is achieved by choosing a potassium chlorate oxidiser, and combining it with magnesium carbonate and sodium bicarbonate, which help stop the reaction getting too hot. Sugar is used as the primary fuel, with both lactose and sucrose being fit for purpose. Color is then added with solvent-based dyes, readily sourced online. These are stable at higher temperatures than typical water-based food grade dyes, and thus are the best choice for creating thick, vibrant colored smoke.

[Tech Ingredients] does a great job of explaining both the theory behind the work, as well as the practical considerations necessary to be successful. The video is the result of much experimentation and work off-camera, which shows in the final presentation. If you’ve been working on your own pyrotechnic creations, be sure to hit up the tips line. Video after the break.

Continue reading “Making Colored Smoke Devices, The Right Way”

Ghost Rider Costume Is Smoking Hot

It’s that spooky time of year once again, with pumpkins and cobwebs as far as the eye can see. This year, [Mikeasaurus] has put together something really special – a Ghost Rider costume with some amazing effects.

The costume starts with the skull mask, which started with a model from Thingiverse. Conveniently, the model was already set up to be 3D printed in separate pieces. [Mike] further modified the design by cutting out the middle to make it wearable. The mask was printed in low resolution and then assembled. [Mike] didn’t worry too much about making things perfect early on, as the final finish involved plenty of sanding and putty to get the surface just right. To complete the spooky look, the skull got a lick of ivory paint and a distressed finish with some diluted black acrylic.

With the visual components complete, [Mike] turned his attention to the effects. Light is courtesy of a series of self-blinking LEDs, fitted inside the mask to give the eye sockets a menacing orange glow. However, the pièce de résistance is the smoke effect, courtesy of a powerful e-cigarette device and an aquarium pump. At 225W, and filled with vegetable glycerine, this combination produces thick clouds of smoke which emanate from the back of the wearer’s jacket and within the skull itself. Truly stunning.

[Mike] reports that the costume is scary enough that he has been banned from answering the door as Ghost Rider. We think it’s bound to be a hit, regardless. For another epic mask build, check out the Borderlands Psycho. Video after the break. Continue reading “Ghost Rider Costume Is Smoking Hot”

Making Smoke That Really Performs

Smoke is a useful thing, whether you want to hide from enemy combatants or just make a big scene at a local sporting match. Smoke devices have lots of applications, many of which will likely cause a nuisance to somebody, somewhere. With that said, they can also be really cool, and [Tech Ingredients] is here to tell you how to make them.

Far from a simple tutorial, the video guide is loaded with detail. It begins with an explanation of the basic chemistry involved, using potassium nitrate and sugar. This is the basis of rocket candy, a popular method for making solid rocket motors at home. However, it’s then explained how the formula is altered to suit a smoke-making, rather than a thrust-making device. The trick is the addition of paraffin to moderate the reaction.

The tips don’t stop there. The guide explains how to use a coffee grinder to make the coarse ingredients finer, which increases the surface area and allows the powder constituents to blend with the wax more easily. Enclosures are also discussed, with a cardboard tube and bentonite clay favored for its heat resistance and stability.

Overall, it’s an excellent guide which takes the time to explain the rationale behind each step in the process. It’s great to see the underlying concepts explained with the practical execution, giving a strong understanding of not just how to do it, but why. Video after the break.

Continue reading “Making Smoke That Really Performs”

Benchtop Fume Extractor Cuts The Cord, Clears The Air

What good is safety gear that isn’t used because it’s annoying and gets in the way of getting the job at hand completed? None, really, and the solder fume extractor is one item that never seems to live in harmony with your workspace. They’re often noisy, they obstruct your vision, and a power cord draped across your bench is a sure way to ruin your soldering zen.

To fix those problems, [Nate] has built a nice battery powered solder fume extractor that’s so low profile and so quiet, you won’t mind sharing a bench with it. Based on a standard 80-mm case fan, the extractor has a built-in 18650 battery for power and a USB charging port. There are nice little features, like a speed control and a low-battery indicator. The fan mounts to a pair of custom PCBs, which form the feet for the fan. [Nate] claims to have run the fan for 12 hours straight on battery before needing a charge, and that it’s so quiet he needs to add a power indicator to the next version. Also making an appearance in rev 2 will be a carbon filter to catch the fumes, but as [Nate] notes, better to spread them around for now than let them go directly up his nose.

Are you in the hacking arts for the long haul? Let’s hope so. If you are, make sure you’re up on the basics of mitigating inhalation hazards.

This USB Drive Will Self-Destruct After Ruining Your Computer

Who would have thought that you could light up pyrotechnics on USB power? This USB keystroke injector that blows up after it’s used proves the concept.

Fully aware that this is one of those “just because you can doesn’t mean you should” projects, [MG] takes pains to point out that his danger dongle is just for dramatic effect, like a prop for a movie or the stage. In fact, he purposely withholds details on the pyrotechnics and concentrates on the keystroke injection aspect, potentially nasty enough by itself, as well as the dongle’s universal payload launching features. We’re a little bummed, because the confetti explosion (spoiler!) was pretty neat.

The device is just an ATtiny85 and a few passives stuffed into an old USB drive shell, along with a MOSFET to trigger the payload. If you eschew the explosives, the payload could be anything that will fit in the case. [MG] suggests that if you want to prank someone, an obnoxious siren might be a better way to teach your mark a lesson about plugging in strange USB drives.

While this isn’t the most dangerous thing you can do with a USB port, it could be right up there with that rash of USB killer dongles from a year or so ago. All of these devices are fun “what ifs”, but using them on anything but your own computers is not cool and possibly dangerous. Watching the smoke pour out of a USB socket definitely drives home the point that you shouldn’t plug in that thumbdrive that you found in the bathroom at work, though.

Continue reading “This USB Drive Will Self-Destruct After Ruining Your Computer”

Current Sink Keeps The Smoke In

One of the most versatile tools on anyone’s work bench, at least as far as electrical projects are concerned, is a power supply. Often we build our own, but after we’ve cobbled together some banana jacks with a computer’s PSU or dead-bug soldered a LM317 voltage regulator to a wall wart, how will that power supply perform? Since it’s not desirable to use a power supply that’ll let the smoke out of everything it powers (or itself, for that matter) a constant current sink, or load, can help determine the operating limits of the power supply.

[electrobob] built this particular current sink from parts he had lying around. The theory of a constant current sink is relatively straightforward so it’s easily possible to build one from parts out of the junk drawer, provided you can find a few transistors, fuses, an op amp, and some heat sinks. The full set of schematics that [electrobob] designed can be found on his main project page. He’s also gone a step further with this build as well, since he shorted out his first prototype and destroyed some of the transistors. But, using a few extra transistors in his design also improves the safety and performance of the load, so it’s a win-win.

This constant current load also has the added feature of being able to interface with a waveform generator (an Analog Discovery, specifically) and as a result can connect and disconnect the load quickly. If you aren’t in need of an industrial-grade constant current sink and you have some spare parts lying around, this would be a great one to have around the work bench.