Non-invasive AC Power Adapter For Exercise Equipment

October 13, 2011 by 27 Comments

We often look at battery-operated hardware and shake our heads at the wastefulness of throwing away disposable batteries. There are some devices that minimize the waste, like those TV remotes that seem to never need new cells. But the C cells that [Quinn Dunki] kept replacing in her elliptical trainer were only lasting about three months at a time. The manufacturer hadn’t cared enough to build a power jack into the machine, so she built her own AC adapter without modifying the stock hardware.

The first thing she did was to patch in a couple of wires between two of the batteries. This let her measure the current consumption, which topped out at around 200mA. This is good news because that’s easily sourced with a cheap linear regulator. Out of the junk box came a 12V/1A wall wart transformer, which just leaves the need for a fuse and some capacitors to finish out a voltage regulator circuit.

Since [Quinn] didn’t want to permanently alter the exerciser, she came up with a way that it could take the same physical space as the batteries. Two long stand-offs are used as prongs to interface the spring terminals in the battery compartment. They attach to a piece of protoboard which hosts the rest of the circuitry. Now she just needs to remember to unplug this from the wall after each session and she’ll be in business.

Hackers Age 14-18 Can Compete To Put Their Project Into Space

October 13, 2011 by 9 Comments

If you’re between the ages of 14 and 18, or have a child who is, here’s a chance to put a project into space. NASA is partnering with YouTube, Lenovo, and a few other entities for a contest that challenges participants to dream up low-gravity experiments. You can enter as an individual or in teams of up to three people, and may put forth up to three experiment ideas for judging. Getting in on the first round is as easy as recording and uploading a video. You’ll need to state a scientific question or principle you want to test, a hypothesis of what can be learned, and a method for testing it.

As with most of the projects we encounter, the seminal idea is always the toughest part. And since the folks here at Hackaday are too old to enter, we thought we’d propose throwing around some ideas in the comments to get the ball rolling (the contest FAQ says it’s okay to get help from others so we’re not ruining it for everyone). We’ll go first.

It looks like experiments can be Biology or Physics related, and can’t use hazardous chemicals, weapons, or anything sharp. We’d love to see some tests that measure how well electronic sensors work in the microgravity. For instance, can you use a gyroscope sensor reliably in micro-gravity? What about an electronic compass; does it always point toward earth? What about robotic propulsion? We’d love to see a minature ROV swimming through the air like a water-bourne vessel would on earth.

Your turn. Leave a comment to let us know what you’d do if you could enter. Oh, and we’ve also embedded the contest promo video after the break.

Continue reading “Hackers Age 14-18 Can Compete To Put Their Project Into Space” →

An Autonomous Minivan For Busy Parents

October 13, 2011 by 22 Comments

Although minivans are a staple of moms and dads that drive their kids to school, soccer practice, and the like, this vehicle imagines a time when maybe they won’t even have to. Autonomous cars have been in development for some time, but the video after the break gives a nice close-up view of how this particular vehicle was built and some of the testing that went into it.

Of particular interest was the external luggage pod modified to hold vehicle electronics. Everything is nicely laid out with wire duct to keep it neat. Those in the manufacturing industry might notice several other off-the-shelf components including an area scanner at 0:24 and extruded aluminum framing at 0:45. The apparent “E-stop” button on the passenger side comes from industry as well and may make the rider feel a bit more safe!
[youtube http://www.youtube.com/watch?v=1o04r1tuKJo&w=470&h=315%5D

If this wasn’t interesting enough, check out this autonomous car by Google that has already driven from San Francisco to Los Angeles!

Candied LEDs Are A Light, Tasty Treat

October 13, 2011 by 17 Comments

rock_candy_diffused_leds

[Emily Daniels] recently snagged a free iPad in the Instructables “Play with your food challenge” with an interesting way to work with LEDs. Growing up, most kids attempted to make, or at least have seen rock candy be produced. [Emily] thought it would be interesting to mix LEDs with the stuff to see what she could come up with, and her candied LEDs are the result.

The process is pretty straightforward, and involves mixing up a batch of supersaturated sugar syrup in which LEDs are suspended. The LEDs act as a nucleation point for the crystal formation, growing a nice solid coating of sugar after a couple weeks’ time. After some cleaning up, the LEDs can be connected to a coin cell battery or similar, as you would normally do. The sugar acts as a diffusing medium for the LEDs, giving them a nice soft beam pattern.

Obviously you likely wouldn’t want to use these for any long-term electronics project, but it’s a fun activity for the kids, and it could be a good way to incorporate electronics into baked goods.

Brewing Up Some Quantum Dots

October 12, 2011 by 7 Comments

We’re taking a field trip from the backyard, garage, and basement hacking in order to look in on what research scientists are up to these days. A group from the Johns Hopkins Institute for NanoBioTechnology has been manufacturing quantum dots for use in the medical field. Made up of Cadmium Selenide, this is a nanomaterial that you can think of as individual crystals of the smallest size possible. Quantum dots have many uses. Here, [Charli Dvoracek] takes the recently manufactured dots and activates them with antibodies capable of targeting cancer cells. Once mixed with a biological sample, the dots embed themselves in the walls of the cancer, allowing the researchers to find those cells thanks to the phosphorescent properties of the dots.

The video after the breaks walks us through the various steps involved in growing these dots. [Charli] has the benefit of a fully outfitted lab, using tools like an argon-filled glove box to protect her from harmful off-gases. You’re not likely have this sort of thing in your home laboratory, but as we’ve seen before, you can make some of your own equipment, and produce interesting chemicals with simple processes. If you’re someone who already tinkers with chemistry experiments we want to hear about your exploits so please drop us a tip about what you’re up to.

Continue reading “Brewing Up Some Quantum Dots” →

USB Killswitch Turns Off Your Home Entertainment Bling Automatically

October 12, 2011 by 16 Comments

Finally, the USB port on the back of your television can be tapped for something useful. [Don] is using this add-on device to automatically cut the power to his Ambilight clone. Initially, he got tired of unplugging the power adapter each time he shut off the television, so he added a switch. But laziness overcame him and he decided he needed an automatic method. After probing around on the connections available, he established that the serial interface (normally used for servicing the device) was not of any use, but the USB port is. He measured the voltage of the power bus to be 5V when the TV is on, and 0.15V when it is off. He whipped up the circuit you see above which uses the USB connection to trigger a relay, connecting power to his Ambilight clone when the television comes on, and disconnecting it when the set is switched off.

Our dream has always been an XBMC capable device that can Velcro to the back of a TV, and be powered from that USB port. Unfortunately the Beagle Board hasn’t yet made it to a stable level when running XBMC. Our next hope is the AppleTV 2, which can run XBMC but would require some hacking to get it working off of the USB port, raising concerns about how much current it would draw at 5V.

Halloween Hacks: Building A Dark Ride In A Garage

October 12, 2011 by 15 Comments

Instead of the usual Jack-o-lanterns and creepy Halloween decorations, [Rick Murphy] built a dark ride in his garage a few years ago.

In case you’ve never been fortunate enough to see one in person, a dark ride is a track-based haunted house meant to be experienced on a small cart. Usually featuring sound, light, and animatronic displays, dark rides can be just as entertaining now as when you were eight years old.

[Rick]’s dark ride, “Scream in the Dark” was built in his 2-car garage over a few years. The kids that went though the ride were genuinely scared, but that made the kids in line even more curious – just the reaction [Rick] wanted.

The build is for the most part completely modular. The track is made up of 4-foot square panels that have either a straight track or 90 degree bend. The modular design means [Rick]’s garage doesn’t need to be a dark ride the entire year. The cart rides on this curved, raised track with the help of a few gear motors and 12 V battery pulled from a Power Wheels.

There’s a great gallery of the interior of the dark ride and a video after the break. If you’d like to build your own dark ride, check out dafe.org for a whole bunch of dark ride and fun house enthusiasts.

Continue reading “Halloween Hacks: Building A Dark Ride In A Garage” →