Hacklet 43 – Flashlight projects

Mankind has always looked for ways to light up the night as they walk around. Fires are great for this, but they aren’t very safe or portable. Even kept safe in a lantern, an open flame is still dangerous – especially around cows.  Enter the flashlight, or torch if you’re from the other side of the pond. Since its invention in 1899, the flashlight has become a vital tool in modern society. From patrolling the dark corners of the city, to reading a book under the covers, flashlights enable us to beat back the night. The last decade or so has seen the everyday flashlight change from incandescent bulbs to LEDs as a light source. Hackers and makers were some of the first people to try out LED flashlights, and they’re still tinkering and improving them today. This weeks Hacklet focuses on some of the best flashlight projects on Hackaday.io!

light1We start with [Norman], and the LED Flashlight V2. Norman built a flashlight around a 100 Watt LED. These LEDs used to be quite expensive, but thanks to mass production, they’ve gotten down to around $6 USD or so. Norman mounted his LED a custom aluminum case. At this power level, even LEDs get hot. An extruded aluminum heatsink and fan keeps things cool. Power is from a 6 cell LiPo battery, which powers the LED through a boost converter. It goes without saying that this flashing is incredibly bright. Even if the low-cost LEDs aren’t quite 100 Watts, they still put many automotive headlights to shame! Nice work, [Norman].

light2A tip of the fedora to [Terrence Kayne] and his Grain-Of-Light LED LIGHT. [Terrence] loves LED flashlights, be he wanted one that had a bit of old school elegance. Anyone familiar with LEDs knows CREE is one of the biggest names in the industry. [Terrence] used a CREE XM-L2 emitter for his flashlight. He coupled the LED to a reflector package from Carlco Optics. The power source is an 18650 Lithium cell, which powers a multi-mode LED driver. [Terrence] spent much of his time turning down the wooden shell and aluminum tube frame of the flashlight. His workmanship shows! Our only suggestion would be to go with a lower profile switch. The toggle [Terrence] used would have us constantly checking our pockets to make sure the flashlight hadn’t accidentally been activated.

light3Harbor Freight’s flashlights are a lot like their multimeters: They generally work, but you wouldn’t want to trust your life to them. That wasn’t a problem for [Steel_9] since he needed a strobe/party light. [Steel_9] hacked a $5 “27 LED” light into a stylish strobe light. He started by cutting the power traces running to the LED array. He then added in an adjustable oscillator circuit: two BJTs and a handful of discrete components make up an astable multivibrator. A third transistor switches the LEDs. Switching a load like this with a 2N3906 probably isn’t the most efficient way to do things, but it works, and the magic smoke is still safely inside the semiconductors.  [Steel_9] built the circuit dead bug style, and was able to fit everything inside the original plastic case.  Rave on, [Steel_9]!

If you want to see more flashlight projects, check out our new list on Hackaday.io! That’s about all the time we have for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Hack a Mag-Lite to be Rechargeable

rechargeMaglite

Most tools sport rechargeable batteries these days, but there’s no need to toss that old flashlight: just replace the cells with rechargable ones!

[monjnoux] had a 3-cell D-sized MagLite lying around—though you could reproduce this hack with a 2 to 5 cell model—which he emptied of its regular batteries and replaced with some 11000mAh NiMHs from eBay. The original bulb was also tossed in favor of a 140-lumens LED.

After disassembling the flashlight, [monjnoux] set about installing the new parts. He replaced the original bulb with the LED, soldering it into place and securing it with hot glue. He then drilled a hole in the body of the flashlight for a DC socket. The charger he purchased is adaptive, detecting the number of cells and adjusting its voltage accordingly. It had the wrong connector, though, so [monjnoux] simply chopped off the end and soldered on a new one. For a hack that comes in at 40€, it’s definitely a cheaper alternative to the official rechargeable model: which costs 80€. And with a duration of 7 hours (though it’s unclear whether this number reflects continuous use), it likely outlasts the official model, as well.

Propane forge built from a soup can

propane-forge-from-soup-can

It doesn’t look like much, but this easy to build propane forge is just what you need to try your hand at blacksmithing. [Code Cowboy] took on the build after watching this how-to video which shows the fabrication of a small knife after completing the forge build.

The first step is to eat all of the soup (or beans if you prefer). With an empty can in hand the stand — made of two angle brackets — and inlet are attached. Next comes the heat proofing for the walls of the forge. At first glance we thought that cat litter was one of the ingredients, but that’s just an empty container used to haul playground sand. The sand is mixed with equal parts of plaster of paris before adding water to achieve a clay-like consistency. This is packed into the can, with a small opening to receive the metal to be heated.

The torch itself can be used to cure the heat shield. After letting the mixture harden a 30 minute burn will force the rest of the water out of the heat proofing.

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Intelligent flashlight will literally show you the way

Flashlights are so 20th Century. Be it the incandescent type that popped up very early on, or LED models with came around in the 90’s, there’s not much excitement to the devices. But [Sriranjan Rasakatla] is doing his best to change that. This is his WAY-GO Torch, an intelligent flashlight (a Smart Light?) that will not just light your path, but overlay useful data on it.

At the front of the unit a pico projector is housed on a jointed assembly. This allows the device to project data on the ground in front of you. Using a digital compass and GPS module, it can show the polar coordinates, guide you on your way, or provide information about the buildings around you. The motorized mount provides image stabilization based on IMU data. Check out the demonstration video after the break. It shows general functionality in the first part of the clip, with some footage of the stabilization system at about 4:30.

This really does seem like it came right out of a Sci-Fi novel. It’s useful, but the complexity makes it surprising that [Sriranjan] was able to pull it off. We wonder how the battery life is on the device, but it can’t be any worse that one of those really huge flashlight builds.

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Building infra red light sources with regular lights

[Oneironaut] sent us another IR hack. This time it is a writeup on the best ways to create IR light sources from regular lights. Since normal flashlight bulbs emit a broad enough spectrum to include visible light and IR light, this basically comes down to filtering. [Oneironaut] explores different light sources and different materials in depth, along with great pictures to show his results. This is a great resource if you’re needing to do some night vision for cheap.

Zinc sulfide glow power at home

Further solidifying her mad-scientist persona, [Jeri Ellsworth] is making glow powder with household chemicals. When we saw the title of the video we though it would be fun to try it ourselves, but the first few minutes scared that out of us.

To gather the raw materials she puts some pennies in a bench motor and files them into powder. From there it’s trial and error with different cleaners and tools to create just the right dangerous reaction to get the chemical properties she’s looking for.

Check out her experiments after the break. And if you find you’re wanting more, go back and take a look at her EL wire fabrication process.

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Switchmode LED flashlight upgrade

When [Neelandan]’s cheap flashlight’s internal rechargeable battery died, he scrounged for a replacement. Ultimately, the brightness of the light suffered with his new battery, taken from an old cell phone since he had dropped the voltage a bit. Upon inspection he saw that he would have to swap the individual resistors for each lamp to get the desired brightness again. This wasn’t really acceptable as he would have to repeat the process if he used another re-purposed battery with different specs. Instead, he added a new circuit to supply constant brightness until the voltage drops below 2.7 volts. We love to see hardware resurrected, even if it is just a cheap LED flashlight.