Gravia: LED Lamp Lit by Gravity Lasts 200 Years, Never Plugs In
When we talk about going off-grid, or otherwise unplugging from traditional power sources, it usually involves solar or wind power, or some other alternative that doesn't involved your local utility. Young designer Clay Moulton has figured out how to harness a different source to create electricity: gravity. "Gravia" is his LED-lit floor lamp that combines human power and gravity to create a lighting source that will work for 200 years or so, and never need to be plugged in. The lamp has a weight that's raised every four hours or so; as it slowly descends, the downward motion is converted to torque via a high-efficiency ball screw. The torque is overdriven (at 1:160 for those of you scoring at home) by a harmonic drive gear hand, and the output from that spins a set of 12 high-strength neodymium magnets (which act as the rotor), spinning to power 10 high-output LEDs. Simple, no? (more)
via:treehugger
