Conductive filament isn’t an ideal electrical conductor, but it’s a 3D-printable one and that’s what makes [Hercemer]’s 3D-printed flashlight using conductive filament work. Every part of the flashlight is printed except for the 9 volt battery and LEDs. Electrically speaking, the flashlight is a small number of LEDs connected in parallel to the terminals of the battery, and turning it on or off is done by twisting or loosening a cap to make or break the connection.
The main part of the build is a 3D-printed conductive cylinder surrounded by a printed conductive ring with an insulator between them. This disk- or pad-shaped assembly forms not only the electrical connection between the LEDs and battery terminals, but also physically holds the LEDs. To attach them, [Hercemer] simply melts them right in. He uses a soldering iron to heat up the leads, and presses them into the 3D-printed conductive block while hot. The 9 V battery’s terminals contact the bottom when the end cap is twisted, and when they touch the conductive assembly the flashlight turns on.
Anticipating everyone’s curiosity, [Hercemer] measured the resistance of his conductive block and measured roughly 350 ohms when printed at 90% infill; lower infills result in more resistance. You can see a video of the assembly and watch the flashlight in action in the video, embedded below.
Instead of a battery, the torch relies on a 1.5 farad supercapacitor to store energy. The body of the torch is constructed out of PVC pipe and fittings, and packs strong neodymium magnets inside. A coil of wire wrapped is formed around an old solder spool, which, when shaken past the magnets, generates a current. This is rectified with a series of diodes and charges the supercapacitor, powering the light.
It’s a classic design that is available commercially, but it’s one easily replicated in the home shop, too. It would make a great educational project, particularly as students would be left with a useful device to take home at the end of the lesson. We’ve seen others resurrect commercial builds with upgrades, too. Video after the break.
Sometimes the simplest hacks are the most useful ones, and they don’t come much simpler than the little supercapacitor LED flashlight from serial maker of cool stuff [Jeremy S. Cook]. Little more than an LED, a supercapacitor, USB plug, and couple of resistors, it makes a neat little flashlight that charges from any USB A power socket and delivers usable light for over half an hour.
It’s neat, but on its own there’s not much to detain the reader until it is revealed as a “Hello World” supercapacitor project from an article in which he delves into the possibilities of these still rather exotic components. Its point is to explore their different properties when compared to a battery, for example a linear voltage drop in contrast to the sharp drop-off of a chemical cell. In the video below the break we see him try a little boost regulator to deliver a constant voltage, with consequent severe loss of lighting time for the LED. It’s by this type of experimentation that we learn our way around a component unfamiliar to us, and the article and video are certainly worth a look if you’ve never used a supercapacitor before.
For most people, a flashlight is just something you keep in a drawer in the kitchen in case the power goes out. There’s even a good chance your “flashlight” is just an application on your phone at this point. But as we’ve seen many times before from mechanical keyboards to Power Wheels, hardcore niche communities can develop around the most innocuous pieces of hardware; and the lowly flashlight is no different.
Case in point, this 14,000 lumen LED flashlight built by [Bryson Hicks]. Designed around a 100 watt module from Stratus LED, the flashlight uses a number of 3D printed components to make itself at home in a suitably hardcore enclosure: a metal ammo can. With the addition of some modular electronics and a rather slick little control panel, his light is ready to deliver an unreasonable level of brightness anywhere he wishes.
The Stratus LED module includes its own driver, and just needs to be hooked up to a suitably beefy power source to do its thing. [Bryson] went with a 4500 mAh LiPo battery that he says gets him about a one hour runtime at full brightness. For somewhat less intense operation, he’s added a potentiometer which interfaces with the module’s driver board to control the LED output. Considering how fast the light sucks down the juice, adding a small LCD battery charge indicator to the top of the device seems like it was a prudent decision.
To prevent you from cooking anyone’s eyes at close range, the light requires you to first “arm” it by flipping the military style protected switch. Once the switch is in the on position, an illuminated push button is used to actually turn the LED module on and off. You can also snap the toggle switch back into the closed and covered position if you needed to kill the light in a hurry.
In the very late 1990s, something amazing was invented. White LEDs. These magical pieces of semiconductors first became commercially available in 1996, and by the early 2000s, you could buy a single 5mm white LED for less than a dollar in quantity one. A year or two later, an astonishing product showed up on infomercials airing on basic cable at 2 a.m. It was a flashlight that never needed batteries. With a small white LED, a few coils wrapped around a tube, and a magnet, you could just shake this flashlight to charge it. It’s just what you needed for when the Y2K virus killed all electronics.
Of course, no one uses these flashlights now because they suck. The early white LEDs never put out enough light, and charging a flashlight by shaking it every twenty seconds is annoying. There is another technology that desperately needs a battery-less solution, though: remote controls. They hardly use any power at all. That’s exactly what [oneohm] did for his Hackaday Prize entry. He created the Undead Remote.
The dream of a battery-less remote control has been dead since your parents got rid of that old Zenith Space Command, but here it is. This is really just a shake flashlight, a diode rectifier, a large capacitor, and some glue. Shake the remote, and you can change the channel. Is it useful? Certainly. Does it look weird and is it slightly inconvenient? Also yes. But there you go. If you want an easy way to deal with batteries in your remote control, this is a solution.
The principle is well understood: use a motor in reverse and you get a generator. Using this bit of knowledge back in 2001 is what kick-started [Ted Yapo]’s Hackaday Prize entry. At the time, [Ted] was searching for a small flashlight for astronomy, but didn’t like dealing with dead batteries. He quickly cobbled together a makeshift solution out of some supercapacitors and a servo-as-a-generator, hacked for continuous rotation.
A testament to the supercapacitors, 17 years later it’s still going strong – leading [Ted] to document the project and also improve it. The original circuit was as simple as a servo, protection diode, some supercapacitors, and a LED with accompanying resistor; but now greater things are afoot.
A DC-DC boost converter enables constant power through the LED, regardless of the capacitor voltage. This is achieved by connecting the feedback pin of an MCP1624 switcher to an INA199 current-shunt monitor. The MCP1624 kicks in at 0.65V and stays active down to 0.35V. This is all possible due to the supercapacitors, which happily keep increasing current as voltage drops – all the way to 0.35V. Batteries are less ideal in this situation, as their internal resistance increases as voltage drops, as well as increasing with age.
When testing the new design, [Ted] found that the gears on his servos kept stripping when he was using them to charge capacitors. Though at first he attributed it to the fact that the gears were plastic, he realized that his original prototype from 2001 had been plastic as well. Eventually, he discovered the cause: modern supercapacitors are too good! The ones he’d been using in 2001 were significantly less advanced and had a much higher ESR, limiting the charging current. The only solution is to use metal gear servos
[VanTourist] — irked by what he sees as complicated project videos — has demonstrated that you can build a high quality, multi-function Bluetooth speaker inside three hours.
Using simple hand tools — primarily a crimper, wire stripper, razor cutter and some glue — he’s packed this repurposed GoPro accessory bag with quite a bit of tech. The main components are a Bluetooth amplifier with a spiffy knob, and a pair of 15W speakers, but he’s also added a 1W LED flashlight, 1A and 2.1A charging ports, a battery charge monitor display, and pilot cover toggle switches for style points. Despite all that crammed into the bag, there’s still a bit of room left to pack in a few possessions! You can check out the build pictures here, or the video after the break.