Bob Wilder owns the new world record for longest-duration indoor flight with a radio-controlled electric airplane. It stayed aloft for 4 hrs, 17 min, and 57 sec.
Wilder says it is important to perform tests to find the maximum thrust using the minimum current draw from the batteries. So he analyzed many combinations of motors, gear ratios, propellers, and batteries. "The real bottom line in producing an airplane that will fly inside for several hours is thrust versus current draw," he says. "That means the size of the battery and the size and efficiency of the motor are key."
Wilder uses a permanent magnet motor from Maxon Precision Motors (Burlingame, CA). He claims that the company's coreless motors provide the low-current consumption needed for extending battery life in competition. The motor's iron-less core eliminates cogging and provides smooth rotation even at the lower speeds required for landings.
For more information about motors from Maxon Precision Motors: Enter 539
Advertised as the "Most Powerful Tablet Under $100," the Kindle Fire HD 6 was too tempting for the team at iFixit to pass up. Join us to find out if inexpensive means cheap, irreparable, or just down right economical. It's teardown time!
The first photos made with a 3D-printed telescope are here and they're not as fuzzy as you might expect. A team from the University of Sheffield beat NASA to the goal. The photos of the Moon were made with a reflecting telescope that cost the research team £100 to make (about $161 US).
The increased adoption of wireless technology for mission-critical applications has revved up the global market for dynamic electronic general purpose (GP) test equipment. As the link between cloud networks and devices -- smartphones, tablets, and notebooks -- results in more complex devices under test, the demand for radio frequency test equipment is starting to intensify.
Much of the research on lithium-ion batteries is focused on how to make the batteries charge more quickly and last longer than they currently do, work that would significantly improve the experience of mobile device users, as well EV and hybrid car drivers. Researchers in Singapore have come up with what seems like the best solution so far -- a battery that can recharge itself in mere minutes and has a potential lifespan of 20 years.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.