Wow you went to great lengths for such a thing. You certainly are a cool youtuber in the tech section. You explain things well and clearly have a good understanding of things. I have thought of things many times and quite a few times ended up stumbling onto your channel. Certainly cool ideas.
David Irving Thanks. There are so many cool things to try that I do seem to end up all over the place! :) Be sure and check out version 2 of this gravity light where I took it even further th-cam.com/video/GisQYoYw05k/w-d-xo.html.
Well done. This has come a long way in one week. 2 min up to 8 min with more brightness is awesome :D I'm uploading a video about cordless drill motors as I type.
Thanks. From all the wonderful feedback I'm getting I've got quite a bit to explore for the next version, including ordering new types of LEDs, new motors, different circuits, ... The result should be even better. And keep in mind that 8 minutes was with just a 2 1/2 foot/0.75 meter drop distance. Raising the current unit to the ceiling it would already be 15 minutes. And I just watched your video. Thanks for the doing all that legwork. It'll come in handy as usual.
Here's how I made my Gravity Light, plus the enhancements that increased the run time from 2 minutes to 8 minutes. Plus, lots of construction tips. Thinking about it, the drop distance is only 2 1/2 feet/0.75 meters. If all I did was raise it to the ceiling, the run time would be 15 minutes! Enjoy!
Shamik Gupta It's possible, yes. BTW You might want to check out version 2 of this. I got it to a much longer run time th-cam.com/video/GisQYoYw05k/w-d-xo.html.
Good work on the rectifier circuit. One question: is the shaft on the microwave motor made from plastic? That seems like it will eventually break from the weight. Another thing to consider would be to use a water filled inner tube for the belt. You need to put the water in under pressure to expand/lengthen the tube. Water doesn't compress so it will keep the tube from crushing, but it will conform to the pulleys better and have more contact area.
At least the exterior part is made of plastic, but it's held up perfectly so far. At some point I'll take it apart and make a point to check the shaft. Thanks for the water belt idea. That should be great for cases like this where the pulley profiles are mismatched.
I don't know what you mean. How would an escapement mechanism help? The capacitor stores any unused energy for later use, though there's not much excess as judged by the fact that after the mass stops falling, the LEDs are powered by the capacitor for only a few seconds longer.
Escapement would slow down the mass falling. Like a traditional Cuckoo clock. Slow and consistent. This would allow changing the weight of the mass and/or the diameter of the pulley and maintain rpms. Hopefully in a way that allows for longer run time.
Thanks! And nope, lifting the a weight using the same weight wouldn't work. Would be neat though, but the conservation of energy doesn't allow it. In case you're interested, I did make a version 2 from what I learned from making version 1 th-cam.com/video/GisQYoYw05k/w-d-xo.html
This is awesome, just one question why didn't you leave the bike frame intact and attach the weight to the peddles Axel, than you could use the gears and there switches and brakes to adjust the energy output?
Thanks. I did use the gears. At 7:16 I point out that I moved the chain to a smaller sprocket and with further refinements in my version 2 (th-cam.com/video/GisQYoYw05k/w-d-xo.html) I had it all the way to the 2nd smallest sprocket Having the bike frame intact would just have made the process of switching gears easier, but there's no need since that's a one-time thing. As for the brakes, I wouldn't want to use them since that would be wasting energy. Far better that I just put on a bigger electrical load.
Thanks. Next step is to try a lot of the great suggestions I've gotten in these comments and elsewhere. The next one should be pretty amazing compared to this one.
Cool idea with using an electric motor as a generator. I really hadn't thought about that. Could that work with any electric motor or are there special properties that I should look for?
I think it works with pretty much any motor, though some may have multiple sets of wires going to them. There's also the consideration of that AC motors are AC generators and DC motors are DC generators, so it depends on which you want.
RimstarOrg Cool! Thanks a lot. It's videos like this that makes me glad I don't immediately throw away stuff that I don't use/are broken. I might use this as inspiration for a lesson at some point.
To avoid having the thing lean over, reducing efficiency, have supporting poles so that the wheel is between them, eliminating the need for the copper pipe and plastic. Then more weight can be added! Also, since the motor has resistance when unloaded, it is very lossy. It would make sense to use a separate gear system that is less lossy (larger gears, fewer of them) and a generator/motor that has good bearings. If possible, have the voltage output be high and have 4 Cree power LEDs like XPG's (more efficient) connected the in a full wave bridge configuration, with the "output" of this bridge shorted. Alternatively, you could just have any even number of LEDs connected so that a few are in series in one direction, and a few in the reverse direction. This eliminates the need for lossy diodes that, in that configuration, are only god for >12V stuff, since it will drop almost 2V, wasting about (~2V x ~0.02A = ) ~1W of power! Good luck on continuing progress on it!
I like your thinking. How about FWBR made from LED's, with a cap and another few leds on the dc output of the FWBR. Just to make sure no power is wasted. Although it may not work as well due to there being 2 LED's in series when the FWBR lights up.
I plan on having better support for the next version. I used what I had on hand this time. But I don't want to add more weight, or at least not much more, I want to keep that manageable. More weight wouldn't be as impressive (or interesting for me.) Thanks for the tip re the Cree LEDs. I'll look into them. I like the bridged LED idea too.
RimstarOrg It looks like cree is achieving over 300 lumens per watt with labratory LEDs, and seems like most of their commercial white LEDs are 90-115 lm/W @ full power. the MK-R states it can be as high as 200 lm/W.
Since its been 8y, maybe you can do an update with some improvements: - currently the tension of the pulley belt is handled by the motor and bearing. Maybe this can be offloaded by moving the motor elsewehere - You can use a BLDC motor with some step-up gears to spin the motor fast, then you get 3 phase AC - use dc-dc smps to transform the power from the motor to any voltage, and before, store the rectified 3 phases in a capacitor bank. The output can be stored in a battery
Thanks for the suggestions. I haven't done anything new in those 8 years but back then I did make a lot of improvements and came up with a version 2 which you can see here th-cam.com/video/foqqxqW8aBg/w-d-xo.html
danh le :) I'm very organized, and have only one project out at a time. Also, I reuse a lot of parts from projects, so I don't really have as many projects to store as you might think, but most of the ones I keep go in individually labeled boxes (I said I'm organized :)). I also clean my place every weekend, and after my video is uploaded on Friday I put everything away, otherwise I wouldn't be able to do that cleaning.
Would be fun to set up camp next to an abandoned unplugged oil well. About 3500 feet deep around here. Should give long run time, but winding it back up might take awhile :( This reminds me that I still have to experiment with a wind belt.
an interesting experiment would be a planetary roller screw that is locked against rotation with a weight on it and using the downward force to turn the threaded shaft and power the generator
Put AC cap on output of generator and more caps after rectifier like 10 000 uF (or just 2nd 4700 uF one) And try to anyhow not use an resistor 91 ohms is small one but still wasting power dc-dc converter sounds good but i don't think it will work And if this gererator puts out small power you can use 0.3v diodes (if you arent already)
Thanks for your input. The 4700uF one was the largest capacitance one I have. I'm ordering some larger ones. The 91 ohms was to protect the LEDs in case current was too high, for example, if the wheel started turning real fast for some reason. I looked at the light output with and without the resistor and decided it was a reasonable safety precaution. I plan on try Schottky diodes, which have the lower voltage drop. There are other options too, such as using two sets of LEDs, in opposite polarities, and doing without the bridge rectifier altogether. I'm exploring different motor options too, so the motor I use may end up being DC instead.
RimstarOrg i know that you need to protect leds but if wheel spins fast than you are generating big voltage and wasting it using only small one You need kind of converter that converts any voltage to voltage that ypu leds need and extra current will be stored in a cap 2 leds sounds good If it were puting low voltage out you can use joule thief...
Excellent I look forward to another cool future video. I've had some success using a 1N23B x-band mixer diode and dipole 6.25cm garden wire antenna which works well if you hold it near a cell phone that is in a call and will light a red LED but gives you very little power when more than 20cm away. Perhaps only really useful close range power transfer or for a remote sensor that would take readings for 5 secs then power down for 23h59m55s and recharge. Not sure how to get useful voltages at low levels either unless I could make a dcdc step up converter to take as low as 0.05v from multiple antenna and boost it to 1.8v for the mcu.
I have to say that the leds output light in a certain angle. this is smaller than your reflector in the flashlight, and thus it won't actually benefit from the reflector. Leds have their own lenses that regulate that angle. maybe you can use 2 big angle and 1 smaller one combined & get rid of that ugly flashlight case
Your videos are really cool, I created a radio station (AM) thanks to you guys and always have my friends that live near listen in. Built your crystal radio too!
You can use a DC generator (really a motor) instead. The only reason I used the the AC generator (also a motor) is because of all the gearing it has inside. That gearing turns the slow rotation of the generator's shaft into faster rotation inside and a higher current and sufficient voltage output. If you try to turn the shaft by hand, it's very difficult, if not impossible. That's because of all the load that that gearing produces. Without that gearing the mass would just quickly fall to the floor. A normal DC generator for example doesn't have all that gearing and so the the mass will just quickly fall to the floor. Your run time will be just a few seconds. During those few seconds the DC generator may create enough current and voltage to power the LEDs, but a few seconds is no good. So if you can find a DC generator that has all the gearing then great, use it. Off-hand I don't know of any, but there may be some. You won't need all the circuitry I needed for the AC generator, but a diode in series with the output to protect the LEDs and a capacitor like I had may still be a good idea. Another option is to use a stepper motor as the generator. Or you can add your own gears and/or pulleys and then go with a normal DC generator, like this one th-cam.com/video/vgg1oJFdvcs/w-d-xo.html, though he made his own DC generator.
+ki jaime I don't have a material list. You should also consider looking at version 2 th-cam.com/video/GisQYoYw05k/w-d-xo.html. It has some improvements.
Ire Min Mon I don't have good numbers for this version 1, but the output of my version 2 gravity light, while powering lights, was around 24 volts and 2.7 milliamps or around 65 milliwatts. You can see that one here th-cam.com/video/GisQYoYw05k/w-d-xo.html
@@RimstarOrg Yes but how did adding rectifier made it last longer? Was it because now full wave was used instead of half wave when LED was connected directly to the generator?
Oh, I misread your question. It wasn't just the rectifier. Moving the chain to a smaller sprocket meant that I could lower the mass to drop more slowly while still turning the generator at a fast enough speed. That's what gave the extra runtime. But the generator speed may still not have been fast enough for a bright enough light. That's where the rectifier helped. The LED operates on DC and I was feeding it AC, so only half of the cycle was being used. With the rectifier, I started using the full cycle. But I also switched to three LEDs. So it was really a combination of all that that gave me a longer time with bright enough light. In case you're interested, I later got around 12 minutes with more changes in my version 2: th-cam.com/video/GisQYoYw05k/w-d-xo.html
Nope. Despite what I said previously, thinking about it again, I guess what allowed me to run longer for version 1 was adding the rectifier circuit which used the power more efficiently by taking more advantage of what was coming from the AC generator. What allowed me to run even longer for version 2 was switching to more efficient types of LEDs. Either way, if you want X amount of brightness then you'll need the same amount of power, unless you can make things more efficient.
sarath kumar I don't know what "ms" shaft is, but it doesn't have to be brass. If ms means mild steel then certainly, you can use that. Also, make sure to check out version 2 of my gravity light for any enhancements there you might want to use th-cam.com/video/GisQYoYw05k/w-d-xo.html.
Good question. Unfortunately I didn't make a note. I suggest measuring the outer diameter of your microwave oven motor's shaft and starting with that. I do have one of the pulleys handy though and just measured the inner diameter as around 5/8" or 15mm.
@@RimstarOrg yeah i will measure but oven motor hasnt arrived... anyway thanks.. i will write here again if i had a question. by the way i am a science teacher in türkiye and this is my science project... thank you so much for posting this video.. helped me so much...
Keep in mind that this was version 1. I also did a version 2. The video for that one is here th-cam.com/video/GisQYoYw05k/w-d-xo.html The full write-up for both versions and with all the videos is on my website here rimstar.org/science_electronics_projects/gravity_light_homemade_diy.htm Good luck with your project. Let me know how it goes.
Any idea on what the efficiency on the system was? Like theoretical energy of the load falling vs how much was actually convered into useful light? Surely this isn't >50% efficient...
26%. That's for my version 2 th-cam.com/video/foqqxqW8aBg/w-d-xo.html which had a run time of around 12 minutes. The calcs are on my webpage here a little more than halfway down rimstar.org/science_electronics_projects/gravity_light_homemade_diy.htm
Chinmay Samant You can use the output to charge a battery or a supercapacitor. In fact I'm storing some energy in my capacitor so that there's still enough light to see by after the mass has stopped falling. You'd probably need to do something with the circuit to make the voltage be higher than your battery voltage so that it'll charge. Note that I have a newer version of this gravity light, version 2, which you can see in this video "Gravity Light (v2) Making and Enhancements".
Thanks, And one more question is there any way by which I can make the cycle continuous in which I don't need to lift the weight again to start the electricity generation process. And at last awesome project.
Chinmay Samant Thanks. There isn't any way of lifting it that will require less energy than you get out of it, so it wouldn't make much sense to. Even the amount of energy you expend to lift it is more than the energy put out by it to power the light. Of course you can do some kind of solar powered lifter or something, but there are more efficient ways of getting energy out of solar.
Wow you went to great lengths for such a thing. You certainly are a cool youtuber in the tech section. You explain things well and clearly have a good understanding of things. I have thought of things many times and quite a few times ended up stumbling onto your channel. Certainly cool ideas.
David Irving Thanks. There are so many cool things to try that I do seem to end up all over the place! :) Be sure and check out version 2 of this gravity light where I took it even further th-cam.com/video/GisQYoYw05k/w-d-xo.html.
Well done. This has come a long way in one week. 2 min up to 8 min with more brightness is awesome :D
I'm uploading a video about cordless drill motors as I type.
Very good indeed. Speaking of cordless drill motors, this is what I'll be using to drive my vents open/closed in the greenhouse.
Thanks. From all the wonderful feedback I'm getting I've got quite a bit to explore for the next version, including ordering new types of LEDs, new motors, different circuits, ... The result should be even better. And keep in mind that 8 minutes was with just a 2 1/2 foot/0.75 meter drop distance. Raising the current unit to the ceiling it would already be 15 minutes.
And I just watched your video. Thanks for the doing all that legwork. It'll come in handy as usual.
Very cool invention and some very nice improvements! Thank you for posting!
Here's how I made my Gravity Light, plus the enhancements that increased the run time from 2 minutes to 8 minutes. Plus, lots of construction tips. Thinking about it, the drop distance is only 2 1/2 feet/0.75 meters. If all I did was raise it to the ceiling, the run time would be 15 minutes! Enjoy!
Amazing!
varun rao
Thanks!
RimstarOrg great job...is there a way you u can increase the time by using a combination of pulleys
Shamik Gupta
It's possible, yes. BTW You might want to check out version 2 of this. I got it to a much longer run time th-cam.com/video/GisQYoYw05k/w-d-xo.html.
RimstarOrg how did you make hole in the motor shaft ?
I love what you have done here. I replicated it and found that using a rubber tubing like for a Slingshot is a great nonslip belt.
Looks great, Bill! Thanks for the tip re the rubber tubing. -Steve
very curious to see next version!
Me to! :) I'm getting lots of good ideas from all the comments! Should be interesting.
Good work on the rectifier circuit. One question: is the shaft on the microwave motor made from plastic? That seems like it will eventually break from the weight. Another thing to consider would be to use a water filled inner tube for the belt. You need to put the water in under pressure to expand/lengthen the tube. Water doesn't compress so it will keep the tube from crushing, but it will conform to the pulleys better and have more contact area.
At least the exterior part is made of plastic, but it's held up perfectly so far. At some point I'll take it apart and make a point to check the shaft. Thanks for the water belt idea. That should be great for cases like this where the pulley profiles are mismatched.
Amazing! just amazing, I have no words for this idea and your work. I really enjoy this!
Awesome invention my friend :) I love it! Thanks for sharing!
Thanks! Glad you like it!
:)
So that's how you did it!
:D The secret's out!
Bellissimo e utilissimo!!
Grazie!
Since you added the bridge rectifier, consider using an escapement mechanism
to considerably adding to the time the mass will fall.
I don't know what you mean. How would an escapement mechanism help? The capacitor stores any unused energy for later use, though there's not much excess as judged by the fact that after the mass stops falling, the LEDs are powered by the capacitor for only a few seconds longer.
Escapement would slow down the mass falling. Like a traditional Cuckoo clock. Slow and consistent. This would allow changing the weight of the mass and/or the diameter of the pulley and maintain rpms. Hopefully in a way that allows for longer run time.
Man, I LOVE this stuff.. Thank You & Congratulations!
Very nice improvements and runtime. Did you measure the output?
You mean of the generator? If I recall correctly, with the LEDs as the load it was around 4 volts and around 3.5 milliamps.
Very nicely done!
Great work done🎉
Can we lift the same weight by providing power to the same weight???
Thanks!
And nope, lifting the a weight using the same weight wouldn't work. Would be neat though, but the conservation of energy doesn't allow it.
In case you're interested, I did make a version 2 from what I learned from making version 1 th-cam.com/video/GisQYoYw05k/w-d-xo.html
@@RimstarOrg sorry but ,i wanted to ask whether the same weight can be lifted with the same motor by providing higher power from solar panel.
I don't know. It's a heavily geared motor, so quite strong at a slow speed. But I don't know how much torque it can produce.
@@RimstarOrg thank you for the response
Thank you for your work.
This is awesome, just one question why didn't you leave the bike frame intact and attach the weight to the peddles Axel, than you could use the gears and there switches and brakes to adjust the energy output?
Thanks. I did use the gears. At 7:16 I point out that I moved the chain to a smaller sprocket and with further refinements in my version 2 (th-cam.com/video/GisQYoYw05k/w-d-xo.html) I had it all the way to the 2nd smallest sprocket Having the bike frame intact would just have made the process of switching gears easier, but there's no need since that's a one-time thing.
As for the brakes, I wouldn't want to use them since that would be wasting energy. Far better that I just put on a bigger electrical load.
What's your next step? Low friction generator or make use of the gyroscopic-effect on the weight side?
Very inspiring - thanks for sharing! ^^
Thanks. Next step is to try a lot of the great suggestions I've gotten in these comments and elsewhere. The next one should be pretty amazing compared to this one.
Cool idea with using an electric motor as a generator. I really hadn't thought about that. Could that work with any electric motor or are there special properties that I should look for?
I think it works with pretty much any motor, though some may have multiple sets of wires going to them. There's also the consideration of that AC motors are AC generators and DC motors are DC generators, so it depends on which you want.
RimstarOrg Cool! Thanks a lot. It's videos like this that makes me glad I don't immediately throw away stuff that I don't use/are broken. I might use this as inspiration for a lesson at some point.
To avoid having the thing lean over, reducing efficiency, have supporting poles so that the wheel is between them, eliminating the need for the copper pipe and plastic. Then more weight can be added! Also, since the motor has resistance when unloaded, it is very lossy. It would make sense to use a separate gear system that is less lossy (larger gears, fewer of them) and a generator/motor that has good bearings. If possible, have the voltage output be high and have 4 Cree power LEDs like XPG's (more efficient) connected the in a full wave bridge configuration, with the "output" of this bridge shorted. Alternatively, you could just have any even number of LEDs connected so that a few are in series in one direction, and a few in the reverse direction. This eliminates the need for lossy diodes that, in that configuration, are only god for >12V stuff, since it will drop almost 2V, wasting about (~2V x ~0.02A = ) ~1W of power! Good luck on continuing progress on it!
I like your thinking. How about FWBR made from LED's, with a cap and another few leds on the dc output of the FWBR. Just to make sure no power is wasted.
Although it may not work as well due to there being 2 LED's in series when the FWBR lights up.
I plan on having better support for the next version. I used what I had on hand this time. But I don't want to add more weight, or at least not much more, I want to keep that manageable. More weight wouldn't be as impressive (or interesting for me.) Thanks for the tip re the Cree LEDs. I'll look into them. I like the bridged LED idea too.
Mongrel Shark What's FWDR?
Power Max
Full-wave bridge rectifier. I had to think a minute too when I first read it. Luckily I'd just made one, so that helped. :)
RimstarOrg It looks like cree is achieving over 300 lumens per watt with labratory LEDs, and seems like most of their commercial white LEDs are 90-115 lm/W @ full power. the MK-R states it can be as high as 200 lm/W.
Since its been 8y, maybe you can do an update with some improvements:
- currently the tension of the pulley belt is handled by the motor and bearing. Maybe this can be offloaded by moving the motor elsewehere
- You can use a BLDC motor with some step-up gears to spin the motor fast, then you get 3 phase AC
- use dc-dc smps to transform the power from the motor to any voltage, and before, store the rectified 3 phases in a capacitor bank. The output can be stored in a battery
Thanks for the suggestions. I haven't done anything new in those 8 years but back then I did make a lot of improvements and came up with a version 2 which you can see here th-cam.com/video/foqqxqW8aBg/w-d-xo.html
how does your house look so neat when you have all these projects?
danh le :) I'm very organized, and have only one project out at a time. Also, I reuse a lot of parts from projects, so I don't really have as many projects to store as you might think, but most of the ones I keep go in individually labeled boxes (I said I'm organized :)). I also clean my place every weekend, and after my video is uploaded on Friday I put everything away, otherwise I wouldn't be able to do that cleaning.
Would be fun to set up camp next to an abandoned unplugged oil well. About 3500 feet deep around here. Should give long run time, but winding it back up might take awhile :( This reminds me that I still have to experiment with a wind belt.
waswestkan Sounds like a good idea. At 3500 feet you would get 175 hours!
I love it! thanks for sharing :)
Very cool
an interesting experiment would be a planetary roller screw that is locked against rotation with a weight on it and using the downward force to turn the threaded shaft
and power the generator
You could add a pulley system to lift the weight back to the top whilst sitting for a mild physical workout!
Your a genius
If I make this gravity light project. How can I store the electricity generated?
amazing.
Put AC cap on output of generator and more caps after rectifier like 10 000 uF (or just 2nd 4700 uF one)
And try to anyhow not use an resistor 91 ohms is small one but still wasting power
dc-dc converter sounds good but i don't think it will work
And if this gererator puts out small power you can use 0.3v diodes (if you arent already)
Thanks for your input.
The 4700uF one was the largest capacitance one I have. I'm ordering some larger ones.
The 91 ohms was to protect the LEDs in case current was too high, for example, if the wheel started turning real fast for some reason. I looked at the light output with and without the resistor and decided it was a reasonable safety precaution.
I plan on try Schottky diodes, which have the lower voltage drop. There are other options too, such as using two sets of LEDs, in opposite polarities, and doing without the bridge rectifier altogether. I'm exploring different motor options too, so the motor I use may end up being DC instead.
RimstarOrg i know that you need to protect leds but if wheel spins fast than you are generating big voltage and wasting it using only small one
You need kind of converter that converts any voltage to voltage that ypu leds need and extra current will be stored in a cap
2 leds sounds good
If it were puting low voltage out you can use joule thief...
Wouldn't it be better to use Schottky diodes because of their lower voltage drop and therefore lower power dissipation in diodes?
I'll have to get some Schotty diodes and try it.
have you ever tried harvesting ambient microwaves?
I've thought about it, but haven't tried it. Someday maybe.
Excellent I look forward to another cool future video. I've had some success using a 1N23B x-band mixer diode and dipole 6.25cm garden wire antenna which works well if you hold it near a cell phone that is in a call and will light a red LED but gives you very little power when more than 20cm away. Perhaps only really useful close range power transfer or for a remote sensor that would take readings for 5 secs then power down for 23h59m55s and recharge. Not sure how to get useful voltages at low levels either unless I could make a dcdc step up converter to take as low as 0.05v from multiple antenna and boost it to 1.8v for the mcu.
Neat!
how made wood frame ?? did you made a woodframe in person??
+김지형 Yes, I made the wood frame myself.
I guess using Schtoky diode, will increase efficiency too...
Do you have the dimensions for all the separate components?
Yes, see my webpage here rimstar.org/science_electronics_projects/gravity_light_homemade_diy.htm
I have to say that the leds output light in a certain angle. this is smaller than your reflector in the flashlight, and thus it won't actually benefit from the reflector. Leds have their own lenses that regulate that angle. maybe you can use 2 big angle and 1 smaller one combined & get rid of that ugly flashlight case
Nice.
(Set screws at 90* hold better)
Applause !!!
How about using of perpetual motion so that there's no need to pull it from time to time?
That would be nice. :)
would it be possible sir?
So is this like free energy, sorry if i mistaken, didn't finish watching video
No. The energy comes from you when you lift the masses to the height that they then fall from.
Your videos are really cool, I created a radio station (AM) thanks to you guys and always have my friends that live near listen in. Built your crystal radio too!
Are you a physicist or engineer; or both?
Do I get a third option? :) I'm just someone who's been making stuff since I was a kid into science just as long.
Can we use dc generator in place of synchronous? If not why?
You can use a DC generator (really a motor) instead. The only reason I used the the AC generator (also a motor) is because of all the gearing it has inside. That gearing turns the slow rotation of the generator's shaft into faster rotation inside and a higher current and sufficient voltage output. If you try to turn the shaft by hand, it's very difficult, if not impossible. That's because of all the load that that gearing produces. Without that gearing the mass would just quickly fall to the floor.
A normal DC generator for example doesn't have all that gearing and so the the mass will just quickly fall to the floor. Your run time will be just a few seconds. During those few seconds the DC generator may create enough current and voltage to power the LEDs, but a few seconds is no good.
So if you can find a DC generator that has all the gearing then great, use it. Off-hand I don't know of any, but there may be some. You won't need all the circuitry I needed for the AC generator, but a diode in series with the output to protect the LEDs and a capacitor like I had may still be a good idea.
Another option is to use a stepper motor as the generator.
Or you can add your own gears and/or pulleys and then go with a normal DC generator, like this one th-cam.com/video/vgg1oJFdvcs/w-d-xo.html, though he made his own DC generator.
thank you.
why not keep it AC and use twice the amount of leds , with half of the LEDs polarity flipped? anyone know if this would work?
Yes, that would work.
You can used 120 volt microwave turntable motor
Yup. That's what I'm using.
what materials to make a gravity light in total ???
+ki jaime I don't have a material list. You should also consider looking at version 2 th-cam.com/video/GisQYoYw05k/w-d-xo.html. It has some improvements.
What's the power output on this thing?
Ire Min Mon I don't have good numbers for this version 1, but the output of my version 2 gravity light, while powering lights, was around 24 volts and 2.7 milliamps or around 65 milliwatts. You can see that one here th-cam.com/video/GisQYoYw05k/w-d-xo.html
How did adding a rectifier double the runtime?
It has a rectifier (well, 4 diodes forming a rectifier circuit).
@@RimstarOrg Yes but how did adding rectifier made it last longer? Was it because now full wave was used instead of half wave when LED was connected directly to the generator?
Oh, I misread your question. It wasn't just the rectifier. Moving the chain to a smaller sprocket meant that I could lower the mass to drop more slowly while still turning the generator at a fast enough speed. That's what gave the extra runtime. But the generator speed may still not have been fast enough for a bright enough light. That's where the rectifier helped. The LED operates on DC and I was feeding it AC, so only half of the cycle was being used. With the rectifier, I started using the full cycle. But I also switched to three LEDs. So it was really a combination of all that that gave me a longer time with bright enough light.
In case you're interested, I later got around 12 minutes with more changes in my version 2: th-cam.com/video/GisQYoYw05k/w-d-xo.html
@@RimstarOrg So if i use only one LED will it run longer?
Nope. Despite what I said previously, thinking about it again, I guess what allowed me to run longer for version 1 was adding the rectifier circuit which used the power more efficiently by taking more advantage of what was coming from the AC generator. What allowed me to run even longer for version 2 was switching to more efficient types of LEDs.
Either way, if you want X amount of brightness then you'll need the same amount of power, unless you can make things more efficient.
can i use ms shaft instead of brass???
sarath kumar I don't know what "ms" shaft is, but it doesn't have to be brass. If ms means mild steel then certainly, you can use that. Also, make sure to check out version 2 of my gravity light for any enhancements there you might want to use th-cam.com/video/GisQYoYw05k/w-d-xo.html.
what are the size of brass tubes?
Good question. Unfortunately I didn't make a note. I suggest measuring the outer diameter of your microwave oven motor's shaft and starting with that. I do have one of the pulleys handy though and just measured the inner diameter as around 5/8" or 15mm.
@@RimstarOrg yeah i will measure but oven motor hasnt arrived... anyway thanks.. i will write here again if i had a question. by the way i am a science teacher in türkiye and this is my science project... thank you so much for posting this video.. helped me so much...
Keep in mind that this was version 1. I also did a version 2. The video for that one is here th-cam.com/video/GisQYoYw05k/w-d-xo.html The full write-up for both versions and with all the videos is on my website here rimstar.org/science_electronics_projects/gravity_light_homemade_diy.htm Good luck with your project. Let me know how it goes.
@@RimstarOrg thanks for your attention .. i have all the pieces. i will build it with my students 😊
@@RimstarOrg what is the name of the pulley that you use? i cant find on the internet?
First i had to do it to
use it to recharge a lithium battery ... that lasts soooo much more😎😎😎
Any idea on what the efficiency on the system was? Like theoretical energy of the load falling vs how much was actually convered into useful light?
Surely this isn't >50% efficient...
26%. That's for my version 2 th-cam.com/video/foqqxqW8aBg/w-d-xo.html which had a run time of around 12 minutes. The calcs are on my webpage here a little more than halfway down rimstar.org/science_electronics_projects/gravity_light_homemade_diy.htm
i wannause to this make cheap camping gear
First sorry had to
what a stupid thing to have in your living room. Your wife would love you.
Fake
If I make this gravity light project. How can I store the electricity generated?
Chinmay Samant You can use the output to charge a battery or a supercapacitor. In fact I'm storing some energy in my capacitor so that there's still enough light to see by after the mass has stopped falling. You'd probably need to do something with the circuit to make the voltage be higher than your battery voltage so that it'll charge. Note that I have a newer version of this gravity light, version 2, which you can see in this video "Gravity Light (v2) Making and Enhancements".
Thanks, And one more question is there any way by which I can make the cycle continuous in which I don't need to lift the weight again to start the electricity generation process. And at last awesome project.
Chinmay Samant Thanks. There isn't any way of lifting it that will require less energy than you get out of it, so it wouldn't make much sense to. Even the amount of energy you expend to lift it is more than the energy put out by it to power the light. Of course you can do some kind of solar powered lifter or something, but there are more efficient ways of getting energy out of solar.