LED Lamp Powered by Gravity
Published by Sierra, on February 28th, 2008 1:07 pm, in the categories: Gadgets
Clay Moulton, the designer, named the it Gravia, a floor lamp capable of spreading light for up to 200 years, using the human power and the gravity properties.
So how does it work?
Gravia lamp’s weight rises every three hours approximately and as it starts to descend, the download motion converts into torque through a ball screw and this torque is overdriven by a harmonic drive gear hand, while the output spins a set of 12 neodymium magnets.
The spinning powers ten LEDs and the light is of 600-800 lumens, or equal to a 40 Watts incandescent bulb.
"In time, the lamp won’t fade but The LEDs produce a slightly unnatural blue-ish light. As the acrylic ages, it becomes slightly yellowed and crazed through exposure to ultraviolet light,” explains the designer. “The yellowing and crazing will tend to mitigate the unnatural blue hue of the LED light. Thus, Gravia will produce a more natural color of light with age.”
The less nice part of this is the fact that the user has to raise the weight from the bottom to the top of the lamp, every three or four hours.
Click and Zoom:
And this is the designer's description:
You may check also the DORmio Mouse powered by laptop heat, another project that caught the attention of people from Greener Gadets.
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I am sorry to report that this lamp will never work. There is only enough energy in a 50 pound mass raised four feet to power the LEDs for a minute or two... not the proposed four hours.
George
George, if you are using the PE = mgh equation,
50 pounds = 22.6 kilograms
four feet = 1.2 metres
22.6*1.2*9.81 = 266.0472 joules.
if thats equal to a 40 watt lightbulb, then that would power the light for approximately 6 seconds.
6 seconds is not the proposed minute or two George.
or the gravia might use different science :S
Thats if the machine is 100% efficient as well. But what do I know, I'm not even in my second year of physics at college.
That would be true if the machine was on a full perpendicular vertical drop. However, as the story states, it "converts into torque through a ball screw and this torque is overdriven by a harmonic drive gear hand." On a 1/10" thread, that means the mass would travel (including rotation) an approximate 125' (assuming a 4' vertical drop).
If they have managed to create the efficiency rate high enough and the friction low enough, the spin of the device on the threads could very well produce enough power for high-intensity LEDs. I'm skeptical about the 4 hour mark, but I could see it running for a couple of hours at least.
And Tom, they're speaking of light intensity (lumens) of a 40-watt bulb, not the power requirements.
I think this is possible, and would like to see the tests and schema,
I think it's possible as well, and thanks for clearing up the power requirement.
I'd love for it to be possible actually, I'd imagine it would be quite cheap considering free light power.
The screw doesn't increase the energy available......At a given height, there's still potential energy equal to mgh. (Otherwise you could get free energy by lifting a weight straight up, putting it on a screw, letting it wind down, taking it off the screw, lifting it straight up, etc. If that worked, we would know about it :-)
LEDs are more efficient than a 40-watt bulb, but you still end up with only a few minutes.
The designer admits as much: "based on future developments in LED technology"
http://www.vtnews.vt.edu/story.php?relyear=2008&itemno=111
i like pies
i like pies too
Lol you guys - it's a 40W equivalent. That means to say, it gives off the same amount of light as a 40W old-style carbon filament edison bulb that are still shockingly (no pun intended) prevalent.
Jut like energy saving light-bulbs, although a lot more efficient, LEDs draw tiny amounts of power for the light they give off because hardly any of the energy supplied is converted to heat as with a normal bulb.
Thus this light is entirely feasible, even if 4 hours seems quite high. With high quality materials perhaps this is entirely possible - check out the same idea but using rotational motion - wind-up LED camping torches.
Ciao!
PS the screw is irrelevant - PE = mgh is final.
It does not work, the creator wrote an apology explaining that his calculations were fatally flawed and that it was only a concept but due to high interest he would try and find a way to make it work, I would link but I can't find the page :-(
He can't apologize because he won at Greener Gadgets.
It is not powered by gravity. It is powered by what moved it against gravity in the first place!!!!
ie people.
Just stumbled here i.e. no physics background
I don't understand a word of what any of you are saying but it all sounds (and you all sound) very clever.
Can you not all get together and make it work cause it is such a cool idea ;)
YES that is an amazing idea, all of us physics people will drop everything we are doing, move to some central location and work laboriously on a difficult, but trivial problem so you can have one more unnecessary light on in your house while shedding one less tear about your energy consumption. We'll get right on it.
Ok, but please fix that 4 hours problem and make it function without the need for the user involvement at every 3-4 hours. :D
Shut up. Someone finally said something positive and helpful on a forum, and you must mock him! As to dropping everything, obviously people posting repeatedly on forums to pick apart everyone else`s ideas have an overabundance of free time. They could do worse than make a human and gravity powered LED light or something equally awesome. I`m with Fergus. Stop bitching and do something productive with your lives. Ta.
you people are pathetic. no one cares how much you know about physics.
@ Doombus:
Last time a bunch of physics people dropped everything they were doing, and moved to some central location to work laboriously on a difficult problem you all came up with a bomb that can level entire cities. Two cities in japan think you all might fuckin owe them a damn self powered light gizmo. Get cracking, nerd.
Good physics here. However, if this design were as fatally flawed as described, wouldn't someone have figured it out pretty quickly?
Hi,
Im bored of having to say 'the best thing since sliced bread', im also tired of the inconvenience of the toaster, can the physics nerds (in the reasearch bunker) make self-toasting sliced-bread, while your at it?..
Hi Guys,
I'm a novice here, but couldn't this concept be applied in the same way a crank powered Flash light works?
Instead of the weight continually falling creating power, couldn't the fall of the weight rotate a generator producing energy to be stored in a capacitor (or what ever they are called) and used for what ever period of time it will run.
One minute of cranking on one of those, produces, what...one hour of light. if it takes the weight a minute to get to the bottom, isn't that the equivalent of hand cranking for one minute...or am I missing something here.
Maybe it's not what he originally intended, but it seems to me it would work, and I'd much rather have the weight do the cranking than me.