Grad student invents gravity lamp
February 19th, 2008A U.S. graduate student won second place in a "Greener Gadgets Conference" competition inventing a floor lamp powered by gravity.
Clay Moulton of Springfield, Va., who received his master's of science degree last year from Virginia Tech, created the lamp as a part of his master's thesis. The LED lamp, named Gravia, is an acrylic column a little more than 4 feet high. The entire column glows when activated by electricity generated by the slow, silent fall of a mass that spins a rotor.
The light output of 600-800 lumens lasts about four hours.
To "turn on" the lamp, the user moves weights from the bottom to the top of the lamp and into a mass sled near the top. The sled begins its gentle glide down and, within a few seconds, the LEDs are illuminated.
"It's more complicated than flipping a switch," said Moulton, "but can be an acceptable, even enjoyable routine, like winding a beautiful clock or making good coffee."
Moulton estimates Gravia's mechanisms will last more than 200 years.
A patent is pending on the Gravia lamp.
Copyright 2008 by United Press International
Feb 12, 2009 |
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Also, the lamp was created as part of a Master's Thesis, not as the Master's Thesis. The Thesis could have been regarding a novel and efficient way to convert linear motion into electrical energy. I bet you could get a PhD for that in the EU.
Who let an engineer in here?
Things like camping trips, emergency lights during the extremely long power outages that sometimes accompany natural disasters like earthquakes or freezing rain (LEDs don't burn out, and it doesn't have batteries, which have expiry dates and need to be replaced every few years even if they are just sitting in storage, and those power outages can last for up two a couple months, even in developed countries. Just look at New Orleans or Quebec a few years ago), out of the way villages in third world countries, etc.
This makes a great replacement for those awful handcranks. I can't stand those things.
very insightful. the dramatic future changes we see will be a result of both finding new sources of local and ambient power, and applying them to suppply technology that has drastically lower power consumption needs........
just imagine that one day you may be able to heat an entire room for a day with a half an hour of spinning a bicycle.
From the CRC reference book:
1 watt = 680 lumens is the maximum effeciency possible for production of light energy.
Assuming the gravia lamp operates at one watt to produce the claimed 600 - 800 lumens makes for an estamate of how long the lamp can operate. Placing 25 Kilograms of mass at the top and having it fall through a distance of 1.5 meters makes less than 400 joules of energy. here is the calculation:
mass * acceleration * distance
= 25kg * 9.8m/sec^2 * 1.5 meters
This would allow the lamp to run for less than 400 seconds or about 6 to 7 minutes.
the claim that the lamp would run for 4 hours is a fraud.
You could imagine a village in the third world with a large version of one of these masses, hoisted up to the top by several strong men and utilising pulleys to give a mechancal advantage.
Perhaps it could be used to light the village for the evening? Or maybe power the music system?
Some quantitative figures on devices that can run at low power would be interesting
There is virtually no engineering in the thesis paper. A committee, who obviously embraced the idea but had no understanding of the engineering limitations, endorsed the design concept. This is equivalent to proposing a design for an automobile that can take off and perform as an airplane while ignoring engineering details like required fuel capacity and engine size to achieve a desired range and load capacity.
All that said, I really do like the artistic rendering of the Gravia Lamp. Just add a power cord to plug it into a convenience outlet and forget the third-world villages. Perhaps the falling weight could still be used as an ON/OFF switch. In the thesis paper, removing just one of the five weights is supposed to stop the ball-screw mechanism from turning. If this were true, then the remaining four weights don%u2019t exert enough force to overcome friction in the mechanism. So, not only is it non-engineered, it is non-engineered in the worst way: it wastes over four-fifths or 80% of potential energy stored in the elevated weights! There is no explanation for why this was supposed to occur.
I recommend that everyone read the thesis paper here:
http://scholar.li...ency.pdf
I recommend that everyone read the thesis paper here (delete carriage returns between lines):
http://scholar.lib.
vt.edu/theses/
available/etd-08292007
-103115/unrestricted/
resonant-frequency.pdf