By Rick BrodiaPosted 10.08.2011 at 3:13 pm 2 Comments
One of the most significant changes might be in speed, says Avi Greengart, the research director for consumer devices at market-intelligence firm Current Analysis. Carriers are rolling out faster 4G LTE (Long-Term-Evolution) networks, and hardware manufacturers will soon produce smartphones with powerful multicore processors.
Running down the far-left column of the periodic table, the readily available alkali metals: lithium, sodium, potassium, rubidium and cesium—all generate potentially explosive hydrogen gas when they touch water. The strength with which they react with H2O goes up steadily in the order listed. Lithium just sizzles, whereas cesium explodes powerfully and instantly. You’d expect that to mean that cesium makes the biggest explosion, but it’s not the case.
When design student Markus Kayser wanted to test his sun-powered, sand-fed 3-D printer, he knew the gray skies outside his London apartment wouldn't do. So he shipped the 200-plus-pound contraption to Cairo, Egypt, flew there himself, and haggled with officials for two days to get it out of customs. A few small "tips" and 11 hours of driving later, he finally made it to the Sahara.
I relocated my shop recently, and packing it up reminded me that years of building have left me with an awful lot of tools. Many of them are very specialized—and in some cases, pretty obscure to the average DIYer—but they’re the ones I always reach for.
12-VOLT TEST LIGHT
A very simple tool that manages to take the guesswork out of jobs like debugging a vehicle electrical system. Ground the clip, and touch parts of the system with the tip. When the light comes on, you have power.
By Andrew RosenblumPosted 09.04.2011 at 6:08 pm 3 Comments
Powered by pneumatic solenoid valves and an Arduino microcontroller, a fire-breathing dragon will be appearing in Marin County, California, on October 31. The project began last year, when the now 17-year-old Sam DeRose and his 16-year-old friend Alex Jacobson teamed up with their fathers, Tony and David, to design a robotic version of the friendly dragon Saphira from the Eragon fantasy novel and movie.
A case in which the conventional wisdom is scientifically inaccurate
By Gordon Mah UngPosted 09.04.2011 at 5:48 pm 0 Comments
Laptop computers used to run on nickel-cadmium batteries, which experienced the "memory effect," where they lost capacity over time if recharged before they were drained. That's no longer the case. Newer laptops use lithium-ion or lithium-polymer batteries. Repeatedly discharging the battery to zero doesn't help a lithium-ion; in fact, it will probably shorten its overall life and capacity.
"Resistive" touchscreens are the type you're most likely to use in a DIY microcontroller project. These consist of two screen layers coated with a resistive material and separated by a small gap. When touched, the layers make contact, creating a voltage divider circuit. The resulting voltage is easily measured and correlated to position. The top layer of the touchscreen is just a clear overlay, though; what really makes it work is the layer underneath.
By Darren MurphPosted 08.11.2011 at 11:01 am 4 Comments
The most affordable way to stay connected is to rely on Wi-Fi to make calls and get online. If you’re stuck in a hotel, plug a $99 AirPort Express into the wall to turn an Ethernet connection into your own personal Wi-Fi network so you can use your smartphone and other devices.
My projects tend to live rough lives. To make it easier to safely house their delicate parts in the future, I devised a torture test to determine which project enclosures best stand up to extreme conditions—and to my abuse.
I built a simple circuit and placed it inside a plastic project enclosure, a PVC electrical junction box, and a Pelican case. Then I subjected all three to torture by water, impact and fire.
Check out the gallery below to see the results of our tests:
The options for streaming music over the Internet have increased so dramatically lately that I’ve found my FM radio has become totally irrelevant. Still, I like to be able to listen to a lot of different types of music throughout the day, and I love radios too much to give up on them completely. Now that several music services, such as Last.fm, have released their programming interfaces to the public, I decided to build a custom Wi-Fi radio that can stream my favorite stations and ensure that I’ll always hear music I like.