Supercap Lights Your Way In Times Of Need

February 10, 2012 by 46 Comments

You won’t find [Antoine] stumbling around in the dark. He just finished working on this LED flashlight which draws power from a super-capacitor (translated). He realized that lighting a high-efficiency LED takes so little power that there are many benefits in play when deciding to move away from batteries. When compared to a super capacitor, batteries have a shorter life span, are heavier, and take up more space.

The biggest drawback of a super capacitor in this situation is the low voltage operation. The output will start at 2.7V and drop as the current is discharged. [Antoine] used one of our favorite simple circuits to overcome this issue, the Joule Thief. That circuit is commonly seen paired with an LED in order to boost input voltage to a usable level. That’s precisely what’s going on here.

The final hack in his circuit is the addition of that red LED which you can see in the middle of the board. This takes the place of a Zener diode and drops the charging voltage to a safe level. That indicator light will not come on until the cap is fully topped off. This way it tells you when the device is done charging.

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Things To Do With Your Laptop Batteries When They’re Dead

September 19, 2011 by 65 Comments

[Roy] over at GeekDad had a dead laptop battery on his hands, and decided he would disassemble it to see what useful things he could do with the cells inside. He mentions in his article that even though your laptop might be convinced that its battery is toast, more often than not just one or two cells are damaged. This may not be news to all of our readers, but is worth pointing out to those who might not be aware.

With the bad cells separated from the good, [Roy] thought up a couple of different uses for his newly acquired batteries. His initial idea was to power an LED flashlight that was made to run on the 18650 cells he recovered from his laptop – not a stretch of the imagination, but definitely useful. The second use he came up with was to pair two of the cells together in order to simultaneously power an Arduino and some small Lego motors.

[Roy] lays out all of the standard caveats you would expect regarding the care and feeding of the lithium cells, and even suggests rebuilding the laptop battery as an option for the more skilled members of his audience.

Now we understand that dismantling and re-using old laptop cells is not necessarily groundbreaking, but it’s definitely something that’s worth a bit of discussion. [Roy] admits that his two ideas fall far short of the “18650 Things” his article title suggests, so how about adding a few of your own?

If you have stripped down some laptop batteries to salvage the cells, let us know what you did with them in the comments – we would be interested in hearing about it.

Lego Technic Super 8 Movie Projector

May 18, 2011 by 17 Comments

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It always blows our mind to see the things that people dream up when playing with Lego. Given enough time, you could likely replicate almost any mechanical device with the right amount and type of blocks.

[Friedemann Wachsmuth] recently wrapped up construction on a very impressive Super-8 movie projector with the help of his friend [Kalle]. The projector is fully functional, and is made completely from Lego aside from the reel spindles, the lens, and the lamp. As you can see in the video below the projector plays the film quite well, and even though it is only lit using an LED flashlight, it’s more than bright enough to get the job done.

The projector boasts automatic film feeding, a 24 fps framerate, as well as fast rewind capabilities – all provided by just two small Lego Technic motors.

You really need to watch the video to appreciate how much work went into this projector – it’s amazing.

[via RetroThing]

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Macro Photos Using An Under-light Rig

December 21, 2010 by 11 Comments

[Aki Korhonen] wanted to tighten up his macro photography setup. He already had the camera for the job, but wanted a fully adjustable target platform that he could easily light. What he came up with is a jig to hold the camera and fine tune the subject of each photo. It uses a frame with a piece of glass whose distance from the lens is adjusted by turning a knob. Below the glass a reflective surface redirects light from an LED flashlight up through the platform, lighting the snowflakes he’s shooting. A fixed LED source is in the plans for the next rendition.

Take a look at the overview of his setup in the quick clip after the break.

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DIY Night Vision Monocle

October 2, 2010 by 29 Comments

This interesting mashup shows it’s easy to make your own night vision goggles. It makes use of just a few parts; the viewfinder from an old camcorder, a low-light security camera module, and a collection of infrared LEDs.

The low-light camera is capable of detecting infrared light, which is invisible to our eyes. If you shine the right IR LEDs on an object, they will cast enough light for the camera to clearly view the objects around you. The camcorder viewfinder is nothing more than a compact way to display what the camera sees. This would be easy to accomplish with a wearable display. It is also beneficial to have a large IR light source so you may consider modifying that giant LED flashlight you’ve been meaning to build so that it operates in the infrared wavelengths.

This project comes from the same source as the Laser Microphone we looked in on last month. Just like that one, there’s plenty of extra information about this build. There’s suggestions for choosing and focusing a light source. This includes using lasers as the source, and binoculars for long-range viewing.

Raid The Dollar Store For An Illuminated Umbrella

November 12, 2009 by 23 Comments

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Here’s a quick and easy illuminated umbrella that [Mikeasaurus] built. How’s this for economical? He found an umbrella that someone left on the bus, and used an LED flashlight and clear poncho from the dollar store for the rest of the parts.

The scavenged LED circuit board is the perfect diameter to fit inside the handle of his umbrella. He removed the middle LED and drilled a hole in the board for the shaft to pass through. Although not well detailed, we gather he managed to shoehorn two CR2032 3v batteries underneath the PCB to power the device. The poncho is wrapped around the shaft to diffuse the light. This is a clever solution as the flexible plastic still allows the telescoping shaft to collapse down to its most compact size.

[Mikasaurus’] umbrella doesn’t make noise or emulate the weather but it is a clever idea. The low difficulty level and availability of parts makes this a great project to do with the young ones who don’t get included in your more intricate hacks.

Underwater Laser, Just Add Shark

October 12, 2009 by 30 Comments

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[iskor12] put together a blu-ray laser that is waterproof and packs quite a punch. At 182 mW there is enough power here to pop dark colored balloons (see the video after the break). To make this happen, he found an LED flashlight that has rubber o-rings for waterproofing. Although small, there is enough space in the case to house the battery, driver, and laser diode. A thick ring of aluminum is placed around the laser diode to act as heat sink.

We’ll admit, we don’t know that much about lasers. This is probably the wrong question to ask, but now that he has this what do you do with it? Leave us a comment about your plans for this diabolical creation.

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