Supercap Lights Your Way In Times Of Need

February 10, 2012 by Mike Szczys 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.

Lamp Upgrade Makes You A Hot-head

January 30, 2012 by Mike Szczys 15 Comments

[Cameron] decided to give his twenty-year-old headlamp a makeover. He uses it when he’s out for a run and wanted to have more light to see where he’s going, as well as a red tail light on the back. The stock design uses an incandescent bulb on the front of the head band, and a battery pack on the back. He managed to convert the device to output 700 lumens without major changes to the form factor of the unit.

The first change he decided on is to use a Cree XLamp which provides the 700 lumens of light by drawing about 9.5 Watts of power. Obviously the original battery pack isn’t going to do well under that kind of load, so he also sourced a 5000 mAh Lithium battery. A bit of circuit design and PCB layout gives him two driver chips for the four-element LED module, a charging circuit for the battery, and an ATtiny13 to drive the head lamp and flash the red LED tail light. See the blinky goodness in the video after the break.

That’s a lot of light, but we wonder if he experiences a warm forehead from the heat sink used to keep that LED package cool? Continue reading “Lamp Upgrade Makes You A Hot-head” →

Intelligent Flashlight Will Literally Show You The Way

January 16, 2012 by Mike Szczys 35 Comments

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.

Continue reading “Intelligent Flashlight Will Literally Show You The Way” →

Powering Kids’ Toys By Hand

October 18, 2011 by Mike Nathan 15 Comments

hand_cranked_toy_piano

[Dominik’s] daughter had an old toy piano that she loved, but when the batteries started to die down, it played awful tones and sounded generally out of tune. While this is likely something our circuit bending friends might be interested in, [Dominik] preferred when things sounded more cheery.

He considered simply replacing the batteries, but it seemed like a far better idea to do away with them altogether. he hunted around for a solution, and eventually found one at the local IKEA store. He grabbed a LJUSA hand-powered flashlight and disassembled it, saving the crank and circuitry.

He installed the crank on the back side of his daughter’s piano, and mounted the electronic bits inside the toy’s shell. The crank spins a brushless motor, generating an AC current which is rectified to DC before being stored in a capacitor. He says that a 30 second crank will play just a few tunes, which isn’t ideal, though it is better than frequently replacing batteries.

[Thanks, Roger]

A Light-Following Pong Game

September 13, 2011 by Jeremy Cook 3 Comments

Although not everyone has the ability to make a hacked Pong game Like [Marcelo], even fewer have the ability or the creativity to come up with the elaborate hack that he did. The basic premise of his game is a version of pong played on a breadboard with a 8×8 matrix of LEDs. The controls are really what sets this hack apart. Instead of using a paddle controller or normal switches, small flashlights are used to control the on-screen (on-LED matrix) paddle. This is accomplished using a series of photoresistors and a PIC processor.

Innovative as this would be by itself, [Marcelo] decided to make a program in Flash to display the action on a computer. Communication is done serially, and C# is used to translate everything as Flash doesn’t natively work with a serial connection.

Another innovation is that there are two LEDs connected on either side powered via pulse width modulation. The lights get dimmer as one player is about to lose. Check out [Marcelo’s] pong game after the break!

Continue reading “A Light-Following Pong Game” →

The Life And Death Of A Fantastically Brilliant Flashlight

August 31, 2011 by Mike Szczys 21 Comments

[Holzleim’s] flashlight build is quite impressive. And the rise and fall of the hardware is quite a story. He designed it as a handheld light, relying on batteries to power a multitude of high-power LEDs inside.From the collection of four 5350 mAh lithium polymer cells he was able to achieve a peak power output that surpasses 500 Watts!

Projects that make use of these powerful LED modules have heat dissipation as a major design element. With this in mind, [Holzleim] used large bars of copper as a mounting surface for each group of modules. The size and thickness of these bars made it difficult to use traditional soldering techniques to affix the bodies of the modules so he ended up using a clothes iron to ramp up the temperature high enough to reflow the solder. Once mounted, most of the LEDs were paired with optics, including that Fresnel lens at the center, to help focus the light.

To keep the batteries topped off, [Holzleim] designed his own external charger which can run off of mains or from a car’s electrical system. Unfortunately he must not have included a way to monitor the battery temperature because one of the cells failed, causing a fire that burnt out the components inside the flashlight. Luckily his wife was home at the time and got the failing device outside where it didn’t cause more damage. We’ve linked to his posts regarding the charging system, the properly functioning light burning paper with its beam intensity, and his sad announcement about the fire after the break.

Continue reading “The Life And Death Of A Fantastically Brilliant Flashlight” →

Building Infra Red Light Sources With Regular Lights

February 2, 2011 by Caleb Kraft 23 Comments

[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.