ASK A GEEK: Scott Fullam
Q: Can I hack a standard flashlight to use LEDs, making it brighter and longer-lasting?
--Jacob Miller, San Diego, Calif.
A: If, like me, you obsessively comb dozens of news sites and blogs to get your daily info fix, RSS is a godsend. Instead of actually visiting each site, waiting for your browser to load pages and slogging through ads and graphics, you can breeze through the latest content from all your favorite sites in one text-only window.
Absolutely. A flashlight with at least three AAA, AA, C or D cell batteries hacked to use three 2300-millicandela LEDs will be as bright as an incandescent and last 5 to 10 times longer. Of course you can add up to 20 LEDs (as long as they fit in the reflector) if you're planning to, say, man a lighthouse with the thing. Use a flashlight with more batteries, get more life. You'll also need a resistor for each LED: For a three-cell flashlight, use 30 ohm resistors, 75 ohm for four cells, 130 ohm for five and so on. (Try digikey.com for the parts.)
Trim the LED leads to about a half inch (maintaining their relative lengths), and the resistor leads to one-eighth inch on one end, 1 inch on the other. Solder the short resistor leads to the long LED leads. Carefully break the old bulb. Use a soldering iron to heat the bottom of the bulb case until you can push a long resistor lead through it, and clip the excess. Solder the hanging LED lead to the flange of the bulb case. Solder the remaining LED/resistor pairs in parallel to the first and stuff them all into the
reflector. Now shine on, you crazy diamond.
Scott Fullam is H2.0's Hackmaster, and author of the recent Hardware Hacking Projects for Geeks ($30, O'Reilly). Now a consultant to consumer electronics makers, Fullam has been a toy designer (he once made Barbie talk) and an Apple engineer, and holds two degrees from MIT.
THE TIP SHEET
Disposable No More
Ritz/Wolf Camera sells an $11, 25-shot, 1.3-megapixel "disposable" digital camera, but with the right software and a hacked USB cable, it's possible to transfer the images to your computer and reuse the camera. Instructions at maushammer.com.--John Maushammer, Carrboro, N.C..
National Geographic's Updated MapMachine
Check out mapmachine.nationalgeographic.com for up to 16 views?including satellite, topographic, street and political?of just about any location in the world. Search by city, country or zip code.--Sree Sreenivasan, H2.0 Web Geek
The RoadWired RAPS pad is like a high-tech diaper for my gadget menagerie, providing an extra layer of shock-absorbing, corrosion-resistant protection for anything swaddled in its Velcro-cornered folds. ($18; roadwired.com)
--Cory Doctorow, editor of boingboing.net and author of the novel Eastern
THIS IS BROKEN
Microsoft's version of onClick="window.open('','popup1','height=200,width=615,scrollbars=yes,resize=no')" target="popup1" class="sidebar">user options
See more examples of things broken at thisisbroken.com.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.