Kinetic accent lighting

Description

In keeping with the philosophy that technology is awesome, but sometimes the most practical solutions don't involve a battery, this project will utilize a falling weight to power a small dynamo that will in turn power LEDs with a sufficient intensity to illuminate a wall sconce appropriate for use as an indoor or outdoor accent light.

Components

1 × Micro dinamo A small generator salvaged from a small hand cranked backpacking flashlight.

1 × Gearbox An off the shelf gearbox used to transfer the energy from a falling weight to the generator

1 × White LEDs To produce the light to illuminate the wall sconce

1 × Weight To drive the apparatus

1 × Fudge-sickle Yep, that's right, a fudge-sickle. I need a popsicle stick so must sacrifice my blood sugar for science and consume this fudge-sicke in order to procure the necessary component.

Project Logs

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Added a drive wheel
travis.r.wheatley • 07/05/2014 at 16:41 • 0 comments

Added a 4" pulley that will act as the drive wheel. I attached this to the 400:1 planetary gear system. This combination should get me pretty close to my target performance. However, after a couple of test spins the high torque involved proved to be a bit too much for the small cotter pin that holds the drive assembly to the central shaft, so need to get myself a new and perhaps sturdier pin before proceeding.
Assembled the planetary gear system
travis.r.wheatley • 06/25/2014 at 18:26 • 0 comments

Spent a little time this morning assembling the planetary gear system. The set consists of 2 4:1 segments and 2 5:1 segments. This allows for ratios ranging from 4:1 all the way up to 400:1. Put the full stack together just to verify functionality. It's pretty apparent that 400:1 is going to be way too much. Next step will be to play with the gear ratios to find the sweet spot.
Scored a nice planetary gearbox set to use.
travis.r.wheatley • 06/24/2014 at 21:34 • 0 comments

Ok, got sidetracked for a few days building an ultralight backpacking tent. Way cool project... but that's another story. Finally got by the hobby shop today and scored a nice planetary gearbox set. It sports configurable ratios ranging from 4:1 all the way up to 400:1. So... should be able to find the sweet spot in there somewhere.
Performance expectations
travis.r.wheatley • 06/12/2014 at 23:24 • 0 comments

So.... 350 grams falling 1 meter will power this puppy for around 6 seconds. We'll err on the side of conservatism and call it 5 seconds to make the math easy. That means that if we raise the height to 2 meters we can expect the time to double to 10 seconds. If the weight is increased to 10 kg with 2 meters of travel distance I should expect somewhere in the neighborhood of 5 minutes of illumination per "charge". Not bad.... not great, but not bad.
Initial proof of concept
travis.r.wheatley • 06/12/2014 at 22:56 • 0 comments

Looked at the guts of the hand crank backpacking flashlight and hooked up a drive shaft to do some initial measurements. I was able to use a weight of 350 g with a drop of 1 meter to drive the generator for approximately 6 seconds. This gives me the baseline numbers I need to calculate how much time I should be able to run the wall sconce for using a weight of 10 kg and a drop of around 2 meters.

View all 5 project logs

Discussions

Adam Fabio wrote 06/18/2014 at 01:57

Thanks for entering your Kinetic accent lighting in The Hackaday Prize! I hope you keep "cranking" on this project and produce some bright ideas! (see what I did there?) Don't forget to keep updating your pictures and documentation as you go!

Are you sure? yes | no

travis.r.wheatley wrote 06/18/2014 at 12:21

Thanks for your witty words of encouragement, Adam. Got side tracked over the past couple of days making an ultralight backpacking tent but plan to get back to this shortly.

Are you sure? yes | no

travis.r.wheatley wrote 06/12/2014 at 18:47

Did some initial baseline testing on the generator this morning. Those test show that a 350 gram weight over a 1 meter distance was sufficient to drive the generator for 6 seconds. In my final design my target is to use a weight of around 10 kg (or less) with a drop of somewhere between 2-3 meters. I haven't yet done the math to determine the gear ratio I will need to deliver similar torque to the generator or the amount of time I can expect the drop to take. But I'll post when I get that figured out.

Yes, I believe the light will be dim, which is why it will be packaged in the form of a wall sconce accent light rather than for general purpose illumination. It should be suitable for something like mood/locator lighting along a shaded garden fence where a solar powered light simply does not receive enough sun to function.

Are you sure? yes | no

Bruce Land wrote 06/12/2014 at 18:13

Interesting. How much weight do you think is practical? How big a drop. I estimated that 10 kg and 1 meter might be acceptable, which means about 100 joules, or 1 watt for 100 seconds. Dropping to 0.1 watt for 1000 seconds starts to sound practical, but I think the light will be dim. What do you think?

Are you sure? yes | no

travis.r.wheatley wrote 06/12/2014 at 18:54

Thanks for the post. I responded, but put it as a project comment rather than a reply to this thread. In short, I believe your estimates to be right on track. My target weight is 10 kg or less with a drop of around 2-3 meters. Yes the light will be dim, but the application as a wall sconce accent light will not require a lot of lumens.

Are you sure? yes | no

Kinetic accent lighting

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Description

Components

Project Logs Collapse

Added a drive wheel

Assembled the planetary gear system

Scored a nice planetary gearbox set to use.

Performance expectations

Initial proof of concept

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