9 ms·

A $5 Lamp Powered Solely by Gravity

253 points by TannerLD 14y ago

ColinWright 14y ago
Previously submitted and seriously doubted: http://news.ycombinator.com/item?id=4889266 http://news.ycombinator.com/item?id=4889266 In that thread[0] revelation[1] said: At perfect efficiency, this seems to give you about 55mW for a hour, if I asked Wolfram correctly (for 20kg lifted one meter) - [2] - So probably a hoax. [0] http://news.ycombinator.com/item?id=4889426 http://news.ycombinator.com/item?id=4889426 [1] http://news.ycombinator.com/user?id=revelation http://news.ycombinator.com/user?id=revelation [2] http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90force+meters+in+milliwatt+hours http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for...
- tonyarkles 14y ago
  If you read some of the followups and tweak the math a little bit, it works out reasonably well. Instead of 20kg and 1m, 20lb and 2m, which comes out about the same (49.42mWh). If you have to lift it every half hour, that's 100mW for a half hour. That's more than enough power to get a useful amount of light out of an LED. For example, this LED uses 68mW https://www.sparkfun.com/products/531 https://www.sparkfun.com/products/531 and is marketed as "so bright that it hurts to look directly at them"
  - duskwuff 14y ago
    That's assuming a perfectly efficient dynamo and no mechanical losses. (Which are both huge assumptions.)
    - icoder 14y ago
      Exactly, and since they state that they think they can make it twice as efficient, that would mean they run at max 50% now.
      - duskwuff 14y ago
        I suspect it's even less than that. A fancy (= expensive!) bicycle hub dynamo has an efficiency of about 70%, and that's assuming that it's operating at peak efficiency, and that there are no additional mechanical losses in the lamp.
  - ars 14y ago
    It's hurts to look at it because it's focused into a very narrow beam. Very bright sure - in one tiny spot, and totally useless to illuminate a room. They even include a photo of the beam pattern - it's almost as focused as a laser. (You can tell on an LED by looking a the top - round tops are focused, flat ones spread out.)
    - tonyarkles 14y ago
      That's fine! It's enough to read a book or do homework after the sun sets. We're not talking first-world style lighting; we're talking about a $5 light that is better than sitting in the dark because you have no electricity and ran out of kerosene to burn.
      - deleted 14y ago
        [deleted]
    - libria 14y ago
      It depends on the type of LED. Back when I was playing with them, Luxeons had a 180 degrees beam pattern while Crees were 70 degrees and neither had a built in lens like the cheap ones do (they used some kind of gel cover). They really should consult some lighting experts or flashlight junkies to get the best bang for the buck.
- pdonis 14y ago
  Um, please read the entire previous thread before dismissing this as a hoax. As you can see from a number of posts that I and others made there, the light is comparable to a kerosene lamp, which is what it's intended to replace. It is not, of course, comparable to the kind of light we in developed countries are used to, but that's not what it's intended for.
  - ars 14y ago
    Using the numbers above and the typical LED efficiency you get 5 lumen of light per half hour ASSUMING perfect mechanical efficiency. http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90force+meters+in+milliwatt+hours+*+%2850+lumen+%2F+w%29+%2F+.5+hour http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for... A simple wax candle produces 11 lumen. And there is no way you will get anywhere near perfect efficiency. So at best, this will product maybe 1/3 of the light from a candle. If you directed that light into a small spot, it could be useful, but of course it's a large device and you can't do that. If you illuminated a room with it it would be enough to walk around and not crash into things, but not enough to read. Another comparison: Assuming a 2 meter by 2 meter room (which is tiny), this would produce 1.3 lux (again, assuming perfect efficiency). Moonlight produces betwen .25 and 1 lux. So at best, with reasonable efficiency, and assuming a tiny room, this is comparable to moonlight under a full moon. Can you read in moonlight? Go try.
    - pdonis 14y ago
      But you can adjust the ballast weight and the height; instead of 20 kg over 1 meter, how about 30 kg over 2 meters? That's a factor of 3 difference.
      - rorrr 14y ago
        How many people can lift 30kg 2 meters up? How about doing it continuously? You're also forgetting that it require human energy to power it, which requires food, which is usually more expensive than batteries or gasoline or kerosine.
- retube 14y ago
  well here's the agency behind it... pretty elaborate if it is a hoax: http://www.therefore.co.uk/our-work http://www.therefore.co.uk/our-work
- ChuckMcM 14y ago
  I don't think its a hoax (I commented in the previous thread, initially skeptical but we worked out the math) It may not be as useful as someone might like, which is to say you won't get a lot of light out of it. But unlike the candle example all of the light will be going roughly one direction. Think 'keychain LED flashlight' kind of light. So in a place that literally has no light, it will be helpful. That last door in the dungeon, your village storage hut 30 miles from the nearest town on moonless nights. If you don't mind running the generator faster you can get brighter light for less time. I took apart one of these [1]: http://www.amazon.com/FR160B-Microlink-Self-Powered-Weather-Flashlight/dp/B001QTXKB0/ http://www.amazon.com/FR160B-Microlink-Self-Powered-Weather-... which is Grundig crank powered radio/siren/flashlight. Its pretty bright, and you can power the LED off the internal generator directly. In fact if you were handy with some shop tools you could probably build your own version of this light with just this radio thing and mechanical connection between the crank and the weight. (You would leave the flashlight set to 'on') You wouldn't get 30 minutes of light, more like 2 minutes. But conceptually the idea is the same. I like the design ethos of the 'clock' style energy source (I've got a grandfather clock that you wind by pulling up the weights on it). I expect in a nominally lit urban environment it will provide little benefit. But that doesn't mean I believe it will be useless in all environments. [1] I've now received 3 of these for 'free' (one as a conference giveaway, one came in a kit of earthquake supplies, and one was added into a garage sale purchase of other stuff. They kinda suck, in that they break pretty easily and once they do they don't work (internal wiring breaks). So finding a broken one shouldn't be all that hard if you're looking to experiment.
degobah 14y ago
Technically powered by the effort of lifting it.
- mmanfrin 14y ago
  Technically powered by the food eaten to lift it. Technically powered by the sun. Technically shut up with useless pedanticism.
  - Jach 14y ago
    It's not very useless. The title suggests a perpetual motion machine, so I was wondering what that was doing on HN. Knowing you have to lift it first (from the article or from the comments) is important to know and lets one think this isn't necessarily made up.
    - bmelton 14y ago
      If you had an infinitely long rope and access to an infinitely deep chasm, then there's no reason it wouldn't be considered a perpetual motion machine.
      - kevinh 14y ago
        With an infinitely long rope and an infinitely deep chasm there would not be substantial gravity pulling it downward to have perpetual motion.
        rtkwe 14y ago
        No gravity would simply approach infinity as you descended the well. And since we're being pedantic that's not an issue.
    - mmanfrin 14y ago
      You infer a perpetual motion machine, they say it is 'powered by gravity'.
dsl 14y ago
Not to nitpick, bit it's not powered by gravity, it is powered by people going over every 30 minutes and lifting a weight back up to its top position. EDIT: Apparently people don't understand that using gravity to generate energy is a thing, and the title "Powered Solely" suggested someone found a way to do that.
- tarice 14y ago
  People couldn't lift the weight without consuming energy from food. Doesn't mean that it's powered by food. The machine converts gravitational potential energy to electromagnetic radiation. People generate the gravitational potential energy by lifting the weight using kinetic energy, which was likewise created by converting chemical energy. It's easier just to say "Gravity" because, without gravity, it wouldn't work with its inanimate weight.
  - emiliobumachar 14y ago
    I suppose it all ultimately comes from solar energy, which, in turn, comes from nuclear fusion.
    - njharman 14y ago
      And the nuclear fusion is started if not powered by the heat and pressure caused by, wait for it... GRAVITY!!!
    - tinco 14y ago
      Which is induced by the intense pressure gravity creates in large lumps of mass :) so yeah..
    - sterna 14y ago
      That is not entirely true. Nuclear fission is not powered by the sun, nor are nuclear fusion plants on Earth (when they arrive). However, fission is only possible because of the existence of heavy nuclei that were initially created during super novae explosions in massive stars billions of years ago so you could argue that is is also at least star powered. The ingredients needed for fusion on the other hand are thought to have been created during the some of the early stages of the Big bang so fusion is truly independent of stars.
Lagged2Death 14y ago
Some people get excited by F1 racing, the Bugatti Veyron, or stuff like the latest iPhone, telling you they are technology enthusiasts or engineering fans. But if you ask me, it's always at the low end of things - like this project - where the really inventive, exciting engineering happening. Sure, something like an F1 car is impressive after a fashion, but considering the price, yeah, well, it better knock my damn socks off or it just looks stupid. Unlimited budgets do not make for impressive engineering, really. Making something that is truly, spectacularly useful like this for $5 ot $10? That is genuinely impressive.
- zem 14y ago
  indeed! having lived in india, i get particularly excited by projects that could provide grid-free lighting and clean water to rural areas. also, a quick plug for my blog [http://aleverlongenough.wordpress.com/ http://aleverlongenough.wordpress.com/] rounding up projects like this - it was unfortunately short-lived because life got busy, but i hope to restart it in 2013.
  - tjic 14y ago
    > i get particularly excited by projects that could provide grid-free lighting and clean water to rural areas. The best way to provide lighting and clean water is via the grid: power lines and water pipes.
    - zem 14y ago
      yes, in the long term i agree, but extending the grid's reach and capacity happens slowly, and in the mean time the poor lead miserable lives. these low-tech stopgap measures are things they can do now to improve their lot, for little up-front cost (in business terms, the grid has lower opex, but way higher capex)
- daeken 14y ago
  > it's always at the low end of things - like this project - where the really inventive, exciting engineering happening. That's why I got into the demoscene. While I'll drool over the crazy new demos pushing the latest GPUs to the limits, it's always more impressive to me when people take extremely limited systems and file sizes and do incredible things with them.
obilgic 14y ago
First thing I thought when I saw the title was: Linux, apache, mysql, php...
- bmelton 14y ago
  I'm not sure why you were downvoted, as I bypassed the article probably at least a couple times before realizing that it didn't say "Lamp Server" and just said "Lamp".
  - rijoja 14y ago
    "A $5 LAMP Server Powered Solely by Gravity", if I read that I would have clicked instantly.
NathanKP 14y ago
Maybe I'm stupid for asking but what is the advantage of this over a spring powered wound clock? My wristwatch can tick for two days on a wind, and while it isn't as cheap as this gravity powered wound clock I'm sure it could be made cheaper. There is nothing special about this invention; purely mechanical "gravity powered" clocks have existed for centuries in the form of old grandfather clocks etc.
- marquis 14y ago
  Yes, I was thinking the same thing. You can buy now on Amazon a hand-crank LED light for $12, so surely these can be made far more efficient and cheaper with $200,000.
  - FrojoS 14y ago
    But those require a battery, which will only survive so many (hundred?) recharges, no?
    - mynameishere 14y ago
      I think they use capacitors. At any rate, almost anything would be better than "gravity power". Even a flywheel.
      - meatmanek 14y ago
        I'm not sure why you think flywheels would be a better energy store than a bag of rocks. Flywheels have a lot of engineering hurdles that can't be met for $5: - they need to be well-lubricated, clear of dust (which I imagine to be a problem in some of the environments they're trying to sell to) - they need to be perfectly balanced, or the shifting center of gravity will vibrate the housing - sapping away precious energy. - they need to run at high, ever-decreasing speeds, which means generators that can extract a constant power level at different speeds
- morsch 14y ago
  The advantage of this lamp over a spring powered wound clock would be that it emits light. The disadvantage is that it's comparatively poor at keeping the time.
jstsch 14y ago
Similar in concept to the Waka Waka light, except that's powered by a solar panel (and some quite nifty electronics): http://www.wakawakalight.com/ http://www.wakawakalight.com/
joeyh 14y ago
I use kerosene lights by choice in the winter in weeks like this one when there is no sunshine. So, here's my firstish world problems take on it. May not apply to people for whom a gallon of kerosine is a significant fraction of their monthly income. I have a hard time seeing myself using something like this, except as task lighting. I'd be fine to have to lift a weight if I was only going to be using the kitchen for 30 minutes (it could even serve as a useful timer), or similar. But getting up every 30 minutes rules out using it anywhere I need longer duration light for eg, reading. Also, anywhere I could use this, I could use any of the many inexpensive crank LED lamps available everywhere, which run for similar amounts of time. The pity is that, with the right design, this could support a longer cord for a further lift distance, so it'd run an hour. Or multiple weights used in sequence or parallel so it can be primed for even longer (iirc that's how my grandparent's cuckoo clock worked). From what I can see, it's not designed to be very hackable, and something like this needs hackability. The LED light is the other problem with it; I'd much rather have a well ventilated kerosine light than blue tinged LED for almost any task. (I'm curious to see studies about kerosine health risks however.) Since this light cannot be moved, it has to illuminate the whole area, and its light doesn't seem up to it, so I'd be doubtful about eg, reading by it either.
- geophile 14y ago
  This idea just hit me, and it's so powerful I'm still reeling. What if someone built a battery-powered weight lifter that would go off every 1/2 hour? You wouldn't have to keep getting up to do it yourself! Not sure if I should patent this, or just donate it to the greater good of mankind.
  - K2h 14y ago
    are you proposing propetual motion? if you have the energy to lift the mass, you have the energy to power the light directly and bypass the losses of setting up the dravity weight again.
- marquis 14y ago
  >a gallon of kerosine is a significant fraction of their monthly income It's not just that, it's also extremely polluting (both for the immediate and greater environments) and dangerous. The kerosene isn't the most expensive part, it's buying a good quality lamp that won't tip over or leak toxic gases. http://flexiwaysolar.com/kerosene-lamps-the-problem/fire-risks-of-kerosene-lamps/ http://flexiwaysolar.com/kerosene-lamps-the-problem/fire-ris...
eliben 14y ago
As always, the devil is in the details here. Does this lamp produce enough light for a family to be motivated to actually lift it every N minutes (e.g. does it produce enough light to read comfortably, or to cook a meal)? Is it durable enough to survive in essentially outdoors conditions in terms of heat and humidity? If the answers to these questions are positive, it's certainly a great invention. If not, back to the drawing board.
cr1st1an 14y ago
I don't quite understand HOW does it turn the weight into energy. Could someone enlighten me?
- RandallBrown 14y ago
  the weight is on a string. That string is connected to a crank that turns a generator as it falls.
  - cr1st1an 14y ago
    Oh, and as I understand, the amount of weight is important due the resistance of the crank?
chrisringrose 14y ago
Pretty cool idea.
praveenhm 14y ago
This is not a new idea. Cuckoo clocks, which is common in germany, works without a battery. we need to pull up the weights everyday.
bobowzki 14y ago
If it's real, I wonder if the gears are noisy...
tessellated 14y ago
I don't seem to be in the target audience but the first question that came up is: How much noise does it make?
lttlrck 14y ago
It's not powered 'solely by gravity' It's powered by a human lifting the weight.
antidoh 14y ago
As we all argue over whether this is powered by gravity, or food, or nuclear fusion, somewhere in a dark hut someone is lifting a weight to attend to the baby that just woke up in the middle of the night.

253 points by TannerLD 14y ago

Previously submitted and seriously doubted: http://news.ycombinator.com/item?id=4889266 http://news.ycombinator.com/item?id=4889266 In that thread[0] revelation[1] said: At perfect efficiency, this seems to give you about 55mW for a hour, if I asked Wolfram correctly (for 20kg lifted one meter) - [2] - So probably a hoax. [0] http://news.ycombinator.com/item?id=4889426 http://news.ycombinator.com/item?id=4889426 [1] http://news.ycombinator.com/user?id=revelation http://news.ycombinator.com/user?id=revelation [2] http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90force+meters+in+milliwatt+hours http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for...

tonyarkles 14y ago
If you read some of the followups and tweak the math a little bit, it works out reasonably well. Instead of 20kg and 1m, 20lb and 2m, which comes out about the same (49.42mWh). If you have to lift it every half hour, that's 100mW for a half hour. That's more than enough power to get a useful amount of light out of an LED. For example, this LED uses 68mW https://www.sparkfun.com/products/531 https://www.sparkfun.com/products/531 and is marketed as "so bright that it hurts to look directly at them"
- duskwuff 14y ago
  That's assuming a perfectly efficient dynamo and no mechanical losses. (Which are both huge assumptions.)
  - icoder 14y ago
    Exactly, and since they state that they think they can make it twice as efficient, that would mean they run at max 50% now.
    - duskwuff 14y ago
      I suspect it's even less than that. A fancy (= expensive!) bicycle hub dynamo has an efficiency of about 70%, and that's assuming that it's operating at peak efficiency, and that there are no additional mechanical losses in the lamp.
- ars 14y ago
  It's hurts to look at it because it's focused into a very narrow beam. Very bright sure - in one tiny spot, and totally useless to illuminate a room. They even include a photo of the beam pattern - it's almost as focused as a laser. (You can tell on an LED by looking a the top - round tops are focused, flat ones spread out.)
  - tonyarkles 14y ago
    That's fine! It's enough to read a book or do homework after the sun sets. We're not talking first-world style lighting; we're talking about a $5 light that is better than sitting in the dark because you have no electricity and ran out of kerosene to burn.
    - deleted 14y ago
      [deleted]
  - libria 14y ago
    It depends on the type of LED. Back when I was playing with them, Luxeons had a 180 degrees beam pattern while Crees were 70 degrees and neither had a built in lens like the cheap ones do (they used some kind of gel cover). They really should consult some lighting experts or flashlight junkies to get the best bang for the buck.
pdonis 14y ago
Um, please read the entire previous thread before dismissing this as a hoax. As you can see from a number of posts that I and others made there, the light is comparable to a kerosene lamp, which is what it's intended to replace. It is not, of course, comparable to the kind of light we in developed countries are used to, but that's not what it's intended for.
- ars 14y ago
  Using the numbers above and the typical LED efficiency you get 5 lumen of light per half hour ASSUMING perfect mechanical efficiency. http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90force+meters+in+milliwatt+hours+*+%2850+lumen+%2F+w%29+%2F+.5+hour http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for... A simple wax candle produces 11 lumen. And there is no way you will get anywhere near perfect efficiency. So at best, this will product maybe 1/3 of the light from a candle. If you directed that light into a small spot, it could be useful, but of course it's a large device and you can't do that. If you illuminated a room with it it would be enough to walk around and not crash into things, but not enough to read. Another comparison: Assuming a 2 meter by 2 meter room (which is tiny), this would produce 1.3 lux (again, assuming perfect efficiency). Moonlight produces betwen .25 and 1 lux. So at best, with reasonable efficiency, and assuming a tiny room, this is comparable to moonlight under a full moon. Can you read in moonlight? Go try.
  - pdonis 14y ago
    But you can adjust the ballast weight and the height; instead of 20 kg over 1 meter, how about 30 kg over 2 meters? That's a factor of 3 difference.
    - rorrr 14y ago
      How many people can lift 30kg 2 meters up? How about doing it continuously? You're also forgetting that it require human energy to power it, which requires food, which is usually more expensive than batteries or gasoline or kerosine.
retube 14y ago
well here's the agency behind it... pretty elaborate if it is a hoax: http://www.therefore.co.uk/our-work http://www.therefore.co.uk/our-work
ChuckMcM 14y ago
I don't think its a hoax (I commented in the previous thread, initially skeptical but we worked out the math) It may not be as useful as someone might like, which is to say you won't get a lot of light out of it. But unlike the candle example all of the light will be going roughly one direction. Think 'keychain LED flashlight' kind of light. So in a place that literally has no light, it will be helpful. That last door in the dungeon, your village storage hut 30 miles from the nearest town on moonless nights. If you don't mind running the generator faster you can get brighter light for less time. I took apart one of these [1]: http://www.amazon.com/FR160B-Microlink-Self-Powered-Weather-Flashlight/dp/B001QTXKB0/ http://www.amazon.com/FR160B-Microlink-Self-Powered-Weather-... which is Grundig crank powered radio/siren/flashlight. Its pretty bright, and you can power the LED off the internal generator directly. In fact if you were handy with some shop tools you could probably build your own version of this light with just this radio thing and mechanical connection between the crank and the weight. (You would leave the flashlight set to 'on') You wouldn't get 30 minutes of light, more like 2 minutes. But conceptually the idea is the same. I like the design ethos of the 'clock' style energy source (I've got a grandfather clock that you wind by pulling up the weights on it). I expect in a nominally lit urban environment it will provide little benefit. But that doesn't mean I believe it will be useless in all environments. [1] I've now received 3 of these for 'free' (one as a conference giveaway, one came in a kit of earthquake supplies, and one was added into a garage sale purchase of other stuff. They kinda suck, in that they break pretty easily and once they do they don't work (internal wiring breaks). So finding a broken one shouldn't be all that hard if you're looking to experiment.

degobah 14y ago

Technically powered by the effort of lifting it.

mmanfrin 14y ago
Technically powered by the food eaten to lift it. Technically powered by the sun. Technically shut up with useless pedanticism.
- Jach 14y ago
  It's not very useless. The title suggests a perpetual motion machine, so I was wondering what that was doing on HN. Knowing you have to lift it first (from the article or from the comments) is important to know and lets one think this isn't necessarily made up.
  - bmelton 14y ago
    If you had an infinitely long rope and access to an infinitely deep chasm, then there's no reason it wouldn't be considered a perpetual motion machine.
    - kevinh 14y ago
      With an infinitely long rope and an infinitely deep chasm there would not be substantial gravity pulling it downward to have perpetual motion.
      - rtkwe 14y ago
        No gravity would simply approach infinity as you descended the well. And since we're being pedantic that's not an issue.
  - mmanfrin 14y ago
    You infer a perpetual motion machine, they say it is 'powered by gravity'.

dsl 14y ago

Not to nitpick, bit it's not powered by gravity, it is powered by people going over every 30 minutes and lifting a weight back up to its top position. EDIT: Apparently people don't understand that using gravity to generate energy is a thing, and the title "Powered Solely" suggested someone found a way to do that.

tarice 14y ago
People couldn't lift the weight without consuming energy from food. Doesn't mean that it's powered by food. The machine converts gravitational potential energy to electromagnetic radiation. People generate the gravitational potential energy by lifting the weight using kinetic energy, which was likewise created by converting chemical energy. It's easier just to say "Gravity" because, without gravity, it wouldn't work with its inanimate weight.
- emiliobumachar 14y ago
  I suppose it all ultimately comes from solar energy, which, in turn, comes from nuclear fusion.
  - njharman 14y ago
    And the nuclear fusion is started if not powered by the heat and pressure caused by, wait for it... GRAVITY!!!
  - tinco 14y ago
    Which is induced by the intense pressure gravity creates in large lumps of mass :) so yeah..
  - sterna 14y ago
    That is not entirely true. Nuclear fission is not powered by the sun, nor are nuclear fusion plants on Earth (when they arrive). However, fission is only possible because of the existence of heavy nuclei that were initially created during super novae explosions in massive stars billions of years ago so you could argue that is is also at least star powered. The ingredients needed for fusion on the other hand are thought to have been created during the some of the early stages of the Big bang so fusion is truly independent of stars.

Lagged2Death 14y ago

Some people get excited by F1 racing, the Bugatti Veyron, or stuff like the latest iPhone, telling you they are technology enthusiasts or engineering fans. But if you ask me, it's always at the low end of things - like this project - where the really inventive, exciting engineering happening. Sure, something like an F1 car is impressive after a fashion, but considering the price, yeah, well, it better knock my damn socks off or it just looks stupid. Unlimited budgets do not make for impressive engineering, really. Making something that is truly, spectacularly useful like this for $5 ot $10? That is genuinely impressive.

zem 14y ago
indeed! having lived in india, i get particularly excited by projects that could provide grid-free lighting and clean water to rural areas. also, a quick plug for my blog [http://aleverlongenough.wordpress.com/ http://aleverlongenough.wordpress.com/] rounding up projects like this - it was unfortunately short-lived because life got busy, but i hope to restart it in 2013.
- tjic 14y ago
  > i get particularly excited by projects that could provide grid-free lighting and clean water to rural areas. The best way to provide lighting and clean water is via the grid: power lines and water pipes.
  - zem 14y ago
    yes, in the long term i agree, but extending the grid's reach and capacity happens slowly, and in the mean time the poor lead miserable lives. these low-tech stopgap measures are things they can do now to improve their lot, for little up-front cost (in business terms, the grid has lower opex, but way higher capex)
daeken 14y ago
> it's always at the low end of things - like this project - where the really inventive, exciting engineering happening. That's why I got into the demoscene. While I'll drool over the crazy new demos pushing the latest GPUs to the limits, it's always more impressive to me when people take extremely limited systems and file sizes and do incredible things with them.

obilgic 14y ago

First thing I thought when I saw the title was: Linux, apache, mysql, php...

bmelton 14y ago
I'm not sure why you were downvoted, as I bypassed the article probably at least a couple times before realizing that it didn't say "Lamp Server" and just said "Lamp".
- rijoja 14y ago
  "A $5 LAMP Server Powered Solely by Gravity", if I read that I would have clicked instantly.

NathanKP 14y ago

Maybe I'm stupid for asking but what is the advantage of this over a spring powered wound clock? My wristwatch can tick for two days on a wind, and while it isn't as cheap as this gravity powered wound clock I'm sure it could be made cheaper. There is nothing special about this invention; purely mechanical "gravity powered" clocks have existed for centuries in the form of old grandfather clocks etc.

marquis 14y ago
Yes, I was thinking the same thing. You can buy now on Amazon a hand-crank LED light for $12, so surely these can be made far more efficient and cheaper with $200,000.
- FrojoS 14y ago
  But those require a battery, which will only survive so many (hundred?) recharges, no?
  - mynameishere 14y ago
    I think they use capacitors. At any rate, almost anything would be better than "gravity power". Even a flywheel.
    - meatmanek 14y ago
      I'm not sure why you think flywheels would be a better energy store than a bag of rocks. Flywheels have a lot of engineering hurdles that can't be met for $5: - they need to be well-lubricated, clear of dust (which I imagine to be a problem in some of the environments they're trying to sell to) - they need to be perfectly balanced, or the shifting center of gravity will vibrate the housing - sapping away precious energy. - they need to run at high, ever-decreasing speeds, which means generators that can extract a constant power level at different speeds
morsch 14y ago
The advantage of this lamp over a spring powered wound clock would be that it emits light. The disadvantage is that it's comparatively poor at keeping the time.

jstsch 14y ago

Similar in concept to the Waka Waka light, except that's powered by a solar panel (and some quite nifty electronics): http://www.wakawakalight.com/ http://www.wakawakalight.com/

joeyh 14y ago

I use kerosene lights by choice in the winter in weeks like this one when there is no sunshine. So, here's my firstish world problems take on it. May not apply to people for whom a gallon of kerosine is a significant fraction of their monthly income. I have a hard time seeing myself using something like this, except as task lighting. I'd be fine to have to lift a weight if I was only going to be using the kitchen for 30 minutes (it could even serve as a useful timer), or similar. But getting up every 30 minutes rules out using it anywhere I need longer duration light for eg, reading. Also, anywhere I could use this, I could use any of the many inexpensive crank LED lamps available everywhere, which run for similar amounts of time. The pity is that, with the right design, this could support a longer cord for a further lift distance, so it'd run an hour. Or multiple weights used in sequence or parallel so it can be primed for even longer (iirc that's how my grandparent's cuckoo clock worked). From what I can see, it's not designed to be very hackable, and something like this needs hackability. The LED light is the other problem with it; I'd much rather have a well ventilated kerosine light than blue tinged LED for almost any task. (I'm curious to see studies about kerosine health risks however.) Since this light cannot be moved, it has to illuminate the whole area, and its light doesn't seem up to it, so I'd be doubtful about eg, reading by it either.

geophile 14y ago
This idea just hit me, and it's so powerful I'm still reeling. What if someone built a battery-powered weight lifter that would go off every 1/2 hour? You wouldn't have to keep getting up to do it yourself! Not sure if I should patent this, or just donate it to the greater good of mankind.
- K2h 14y ago
  are you proposing propetual motion? if you have the energy to lift the mass, you have the energy to power the light directly and bypass the losses of setting up the dravity weight again.
marquis 14y ago
>a gallon of kerosine is a significant fraction of their monthly income It's not just that, it's also extremely polluting (both for the immediate and greater environments) and dangerous. The kerosene isn't the most expensive part, it's buying a good quality lamp that won't tip over or leak toxic gases. http://flexiwaysolar.com/kerosene-lamps-the-problem/fire-risks-of-kerosene-lamps/ http://flexiwaysolar.com/kerosene-lamps-the-problem/fire-ris...

eliben 14y ago

As always, the devil is in the details here. Does this lamp produce enough light for a family to be motivated to actually lift it every N minutes (e.g. does it produce enough light to read comfortably, or to cook a meal)? Is it durable enough to survive in essentially outdoors conditions in terms of heat and humidity? If the answers to these questions are positive, it's certainly a great invention. If not, back to the drawing board.

cr1st1an 14y ago

I don't quite understand HOW does it turn the weight into energy. Could someone enlighten me?

RandallBrown 14y ago
the weight is on a string. That string is connected to a crank that turns a generator as it falls.
- cr1st1an 14y ago
  Oh, and as I understand, the amount of weight is important due the resistance of the crank?

chrisringrose 14y ago

Pretty cool idea.

praveenhm 14y ago

This is not a new idea. Cuckoo clocks, which is common in germany, works without a battery. we need to pull up the weights everyday.

bobowzki 14y ago

If it's real, I wonder if the gears are noisy...

tessellated 14y ago

I don't seem to be in the target audience but the first question that came up is: How much noise does it make?

lttlrck 14y ago

It's not powered 'solely by gravity' It's powered by a human lifting the weight.

antidoh 14y ago

As we all argue over whether this is powered by gravity, or food, or nuclear fusion, somewhere in a dark hut someone is lifting a weight to attend to the baby that just woke up in the middle of the night.