LED lamp uses grandfather clock mechanism for power
The second place winner in the "Greener Gadgets Competition" is Clay Moulton's LED lamp, which uses a gravity mechanism to generate electricity. To light the lamp, you lift the weight and let it slowly fall.
Link (Thanks, Tom!)A Virginia Tech student has created an LED floor lamp that is powered by gravity, using a weight slide similar to the concept of a grandfather clock. The lamp puts out the equivalent of a 40-Watt bulb, and lasts four hours per cycle. The mechanism is expected to last 200 years.
To "turn on" the lamp, the user moves weights from the bottom to the top of the lamp. An hour-glass like mechanism is turned over and the weights are placed in the mass sled near the top of the lamp. The sled begins its gently glide back down and, within a few seconds, the LEDs come on and light the lamp, Moulton said. “It’s more complicated than flipping a switch but can be an acceptable, even enjoyable routine, like winding a beautiful clock or making good coffee,” he said.
the latest
latest episodes
It really bothers me that there's such elegant solutions to the energy problem, and yet I'm sure it will take a crisis for them to be adopted.
I did the math, and it doesn't seem like the physics work -- either the weight is 10 tons, the light only lasts for 35 seconds, or the light is super-dim... not the 50 lbs/4 hours/40-watt equivalent listed.
To calculate the needed weight:
700 lumens @ 90 lm/watt (an efficient LED) = 7.78 watts.
7.78 watts * 4 hours = 31.1 Watt-Hour = 112,000 Joules
Potential energy of 4 feet high weight = mgh = mass * 9.8 m/s^2 * 1.22 meters
112,000 Joules = mass * 9.8 m/s^2 * 1.22 meters
==> mass = 9367 kg = 20650 pounds = 10 tons.
It's still a beautiful light & a cool design. The VT Architecture is awesome (I got an EE degree from there).
umm,40 watts as in electricity consumed or 40 watts as in light output? .. if I'm framing that right.
In any case, sweet. If it works, I want one.
Screw this wind crap. Gravity power plants. There. I'm the first to say it. Patent it if you want.
A lamp that lasts 200 years? The Lamps Plus cartel will never allow such a device to be made.
Wow, absolutely amazing stuff. Now, all they need to do is make a winder that uses pressure differential like this "perpetual" clock: http://en.wikipedia.org/wiki/Cox's_timepiece
mercury barometer, ingenious. How about a staircase generator? (not the waveform) Piezo plates for step treads?
This is an industrial design presentation and should not be interpreted as plausible. This is "concept: Gravia," emphasis on "concept"-- check out page 27 of the master's thesis-- it's about presentation. Engineering-wise, it's a >1 efficiency proposition no matter how you slice it. File under "perpetual motion."
Damn, well, go figure. I still want one.
I just love the idea of engineering clockwork driven LED light fixtures.
Very steam punk.
Drag out and dust off those old family heirlooms - hack 'em with small generators and pimp 'em out with LED's. Real grandfather clocks that illuminate. Jam a bright blue bulb up the arse of that little annoying bird that pops out al the time. Make a sensuous glow come from your great grannie's old mantel clock.
Brilliant!
@morcheeba: either the weight is 10 tons, the light only lasts for 35 seconds, or the light is super-dim...
Well, the weight is stated as 50 pounds in one of the diagrams...
@11 Um, did you miss like three words later where morcheeba said that it couldn't be the 50 pounds indicated?
I don't see anything wrong with m's math. Looks like you will need a crane to start your lamp.
"Young lady, around this house we obey the laws of Thermodynamics"
The claims are outright fraud, and would only work if 2 + 2 = 400...
Here's the whole math:
0lbs == 22.6 kg
4 ft == 1.21 m
Potential Energy = mgh = 22.6 kg * 1.21 m * 9.8 m/s^2 ~= 270 J
Power = energy/time = 270 / (60 minutes/hour * 60 seconds/minute * 4 hours) = .019 Watts.
Assume 100% conversion of that power into visible light (a PERFECT lamp) is 683 lumens/watt. So this would be 12 Lumens of output.
A typical 40W bulb outputs 500 lumens!
So the design is a FRAUD, it CAN'T WORK! In order to get the 500 lumens of output, with theoretically perfect efficiency, it either needs 40x the weight (so a TON of weight, literally), 40x the drop (so a 160 foot fall), or can only operate for 6 minutes, and this would be with a perfectly, 100% efficient conversion of the potential energy into power and the power into illumination.
Its not a green design, its outright snake-oil, and if it worked as advertised it would violate the laws of physics.
Page 27 of the thesis presents the lamp as a generator with a 1:160 gearing mechanism and "harmonics" [COUGH!] somehow producing the energy.
I'm disappointed that Mark's original post didn't come with a heavy dose of skepticism-- instead, it was presented as "this is neat!" The link leads to "Pure Energy Systems"-- they don't seem to distinguish between real and fictional gadgets.
Actually, what really make it look bad is Virginia Tech crowing about it!
The physics don't work out assuming constant power. But just a thought...
Frequently with LED lights, you don't actually have the LED on all the time. Very short but high frequency pulses (i.e. low duty cycle).
Above a certain threshold you can't tell the light is flashing, but it is.
Additionally, you don't have to be able to provide the instantaneous power on each cycle - you have the time between cycles to accumulate it. Think of a camera flash and how it charges. Now speed it up.
I have not worked out the numbers for this assumption, but it may at least come closer to working, as opposed to being off by a factor of 1000 in the constant-power case.
Salsaman - Harmonic Drive is a real, and really cool gearing system: http://en.wikipedia.org/wiki/Harmonic_drive
Animation: http://www.harmonicdrive.net/reference/operatingprinciples/movie.php
It's great for hi-gear-ratio reduction and can be built on to the end of a motor, so it's been used in robotic arms that need to be thin & have high-torque.
I liked your earlier comment, too - As a design presentation it's really good. But, the goal was to "come up with new and innovative solutions to address the issues of energy, carbon footprint, health and toxicity, new materials, product lifecycle, and social development."... so, with a 200 year life, they must have been going for product lifecycle & not energy conservation. Of course, most lamps (not bulbs) would last 200 years, too.