PDA

View Full Version : Power generating light



Frolicking Dino
2006-12-18, 11:25
The discussion of light in the general forum got me to thinking - has anyone investigated the idea of using the normal jostling that goes with hiking, solar energy or even something like a tiny water wheel to generate the tiny amount of electricity needed to recharge an LED type headlight? Since these items use a very limited amount of power, it would seem to be something that could be done.

JAK
2006-12-18, 13:09
I was thinking about that myself. It might not save much on battery weight, and probably wouldn't even break even on weight unless on a really long trip where you would run out of food anyways, but still there is a certain aesthetic and peace of mind that would go with being self-sufficient, like using a wood stove and firestarter rather than a canister stove and lighter.

The tricky part is not so much the amount of energy required, but the fact that batteries need to be recharged slowly. It would be a good application for solar power. Another possibility would be a small capacitor charged by hand, and then slowly discharged to recharge your battery. Here are some quick links.

Solar Battery Charger:
http://store.sundancesolar.com/poso4aafosob.html
Weighs 3.4 oz. recharges 4 AA in 8 hours full sun or 2 AA in 4 hours full sun.
4AA weigh 3.8 oz, so break even would be about 8 AA batteries.
Perhaps it could be trimmed down to 2oz for just 2AA in 8 hours full sun.

Others ready for hiking:
http://www.fortune3.com/~comp69793/Products-SOLAR_POWER_1.html

Perhaps the lightest for ultralight DIY projects:
http://www.solar-world.com/PowerFilm.htm

Hamster powered alternative:
http://www.otherpower.com/hamster.html

Frolicking Dino
2006-12-18, 14:28
[/URL] Hamster powered alternative:
[URL]http://www.otherpower.com/hamster.html (http://www.solar-world.com/PowerFilm.htm)Perhaps shelter mice have a use after all....

Iceman
2006-12-18, 23:49
I was thinking squirrel and chipmunk. Besides, once you have charged up your batteries, you can power up your stomache with the tasty little devils. Now that's dual use! :biggrin: :eating: :biggrin:

It's all about food.

dropkick
2006-12-19, 16:37
I read at night if I have spare batteries. Usually they last one to two nights before I have to change.

As I ran my LED flashlight for the first 2 years on the same 2 AA batteries that I started with, and only changed them out when I started to worry about how old they were getting.
I don't worry anymore about my flashlight batteries being used up.


Somewhere there's a thread about a pack with a Faraday(sp?) generator in the frame. - The movement of your walking moves a magnet up and down past a coil of wires generating current in them.


--I don't know if Faraday actually invented this generator, I think he was around to late to have been the one. But I've seen that they call it a "Faraday generator" on the flashlights, and so...

dropkick
2006-12-19, 16:45
I was thinking about that myself. It might not save much on battery weight, and probably wouldn't even break even on weight unless on a really long trip where you would run out of food anyways, but still there is a certain aesthetic and peace of mind that would go with being self-sufficient, like using a wood stove and firestarter rather than a canister stove and lighter.

The tricky part is not so much the amount of energy required, but the fact that batteries need to be recharged slowly. It would be a good application for solar power. Another possibility would be a small capacitor charged by hand, and then slowly discharged to recharge your battery. Here are some quick links.

Solar Battery Charger:
http://store.sundancesolar.com/poso4aafosob.html
Weighs 3.4 oz. recharges 4 AA in 8 hours full sun or 2 AA in 4 hours full sun.
4AA weigh 3.8 oz, so break even would be about 8 AA batteries.
Perhaps it could be trimmed down to 2oz for just 2AA in 8 hours full sun.

Others ready for hiking:
http://www.fortune3.com/~comp69793/Products-SOLAR_POWER_1.html

Perhaps the lightest for ultralight DIY projects:
http://www.solar-world.com/PowerFilm.htm

Hamster powered alternative:
http://www.otherpower.com/hamster.html


I built a charger with the powerfilm quite a while ago. It takes about 10 hours to completely recharge 2 AA's. The battery box is the heaviest part. the whole thing weighs in at about 1.5 oz. If I eliminate the box and go with duct tape it's even lighter.

TeeDee
2006-12-20, 18:55
Two links - the first for a backpack that uses the motion of walking while carrying the packpack to generate electrical energy:

http://www.msnbc.msn.com/id/9245155/

That article is from Sept. 2005

The second one:

http://www.msnbc.msn.com/id/16299917

is from today. The same researcher(s) invented both backpacks. The second backpack claims toallow the backpacker to expend the same energy carring about 12 lbs more. Maaaaaan I want one of those.

TeeDee
2006-12-20, 18:58
Also, take a look at this flashlight. Not exactly new, but still the best in it's catagory:

http://www.appliedinnotech.com/

Steinberger
2006-12-27, 10:51
For my freshman practical I created a device that used peizo-electric crystals to power a battery charger. It did work. It didn't create that much more but that was because I was too cheap to buy more than 4 crystals. If you had about 10 in there you could get a decent voltage. The main problem with the design is having the wires running up your leges to get to the charger. It's very annoying. I had designed it with the sole purpose to have the generator mounted in a hollow sole of a shoe but nevergot around to it. Maybe some day...

Iceman
2006-12-27, 11:05
OK, now you got me interested.... Can you show us your concept/design, maybe a photo or drawing?

Steinberger
2006-12-27, 12:01
I don't have it anymore because the comittee takes the projects after their built to grade but I'll try to make a quick diagram. There is actually a person who is doing the same thing as me trying to get a production model out as well. DARPA is also looking into this technology for feasability for soldiers.

Steinberger
2006-12-27, 12:58
Sorry for the extremely crude drawing but, I'm kind of in a hurry...

http://bulldog.unca.edu/~alcarter/piezogenrough.GIF

Iceman
2006-12-27, 23:39
Ok, I am making a stretch here and guessing that you mount one half of the equation to each pant leg, passing motion causes an electric charge to generate and upload to a remote cell, sort of an open Faraday design? Or are you designing independant units in the shoes? Or am I just a dufus?

You will have to pardon me, I am not really "up" on these super duper top secret electrical generating bouuncy shoe leg thingy's. Sorry.

Steinberger
2006-12-28, 02:04
Well to understand this you have to understand what the piezo-electric effect is. In lamens terms the piezo-electric effect is when a certain type of crystal that demostrates the effect is put under physical stress it creates energy this effect is also reversable.
The design works bywhen you take a step the cermet panel gets forced bown onto the crystal creating a joult of electricity which is smoothed out and regulated by capacitors and resistors.

So petty much the force of the impct of your step is converted into electricity.

Each unit can operate individually but for balance I would have one in each shoe which would also double your output.

There are a few bugs to be worked out like people who walk very softly like sneaking around and walking on very soft surfaces can both decrease the output but, for most people, especially people trudging around after a few miles of hiking, this kind of step is perfect for it

Iceman
2006-12-28, 03:15
So what you are saying is; "I am a dufus". (Many here would probably agree.)

Hey just kidding, sounds like a great project. And to think, when I was in school, our projects included glue and craft paper and rubber bands...

How about my epiphany which involves a leg powered pendulum Faraday generator? Pretty cool. Imagine, each pendulum swing of the leg generates a charge, juice stored in a waist pack? Huh? Huh? Huh? Maybe I should go back to school...

Frolicking Dino
2006-12-31, 17:14
::: Makes note of use of thigh friction to generate electricity :::

Stienberger, interesting concept and if the problem with the wires on the legs could be worked out, one that just might work for backpacking.

GGS
2006-12-31, 19:54
::: Makes note of use of thigh friction to generate electricity :::

Stienberger, interesting concept and if the problem with the wires on the legs could be worked out, one that just might work for backpacking.

LOL! Break out the wool cordoroys(sp) for hiking! Fwoom, Fwoom, charge your batteries!

Seriously, unless I misunderstood Stienberger's post... A piezoelectric device is simply a crystal that generates an electric charge when placed under pressure, or in reverse, expands/contracts when subjected to an electric current. Piezoelectric speakers are very common, just a crystal attached to a horn, hook an audio signal to it and the expansion/contractions generate sound. Place such a crystal in your shoe and WITH EACH STEP you would generate an electric pulse. Now just harness that pulse with electronics. Nothing to do with leg friction... Not that you don't have an idea there...

Ya know Stiengerger, rather than running a wire up your boot, what if you put an AAA battery compartment on the upper heel of each boot? Now you would not have to run wires up your leg...

KLeth
2007-01-01, 03:02
Certain wristwatches allows you to recharge you watch simply by moving your wrist (http://seiko-kinetic-watches.watch-universe.com/seiko_kinetic_watches_wk.htm).
Similar could be transferred to a pack, letting the weight-shifting of the body move the pendulum.
I am thinking of magnetic ball rolling in horizontal placed slightly curved tube with small coil(s) around or vertical (coil surrounded) tube with magnet suspended in springs. a couple of diodes, capacitors ect. and energy could be stored in AA/AAA cell.

The worst issue is that the entire build has to be efficient and light enough, so it would not be smarter to just bring alkaline cells :biggrin:

Steinberger
2007-01-01, 05:46
LOL! Break out the wool cordoroys(sp) for hiking! Fwoom, Fwoom, charge your batteries!

Seriously, unless I misunderstood Stienberger's post... A piezoelectric device is simply a crystal that generates an electric charge when placed under pressure, or in reverse, expands/contracts when subjected to an electric current. Piezoelectric speakers are very common, just a crystal attached to a horn, hook an audio signal to it and the expansion/contractions generate sound. Place such a crystal in your shoe and WITH EACH STEP you would generate an electric pulse. Now just harness that pulse with electronics. Nothing to do with leg friction... Not that you don't have an idea there...

Ya know Stiengerger, rather than running a wire up your boot, what if you put an AAA battery compartment on the upper heel of each boot? Now you would not have to run wires up your leg...

That could definitely work. There are a few issues(weight in shoes, lack of power options) with it but it would simplify it.

I've thought of using a thicker-guaged tracer wire because the current shouldn't be more than what it would be able to handle but the wire can be very fragile.

The nice thing about peizo electricity is that it produce much higher concentrations of energy per weight. Many flintless lighters use the same technology to generate a spark powerful enough to ignite the fuel. and the design would give you an almost limitless supply of power, the pull of your weight from gravity and the force of the impact of your steps.

The other thing is the durability of the crystal. Even though they can last some time this set-up is putting far more force than any other use on the crystal. Even with the safety stops put in on it, I'm not sure how well it will wear over the months.