You can get electricity from a Potato, but..... 2

[nornrich]

All,

I am looking for a means to power an LED through vibration. The vibration would come from an engine being on and the LED would only be on when the engine is on. I've seen flashlights that you can shake and they will store a charge for a period of time. I am looking for something that will provide a continuous flow of current and also charge a rechargable battery at the same time.

Regards,

Rich....

Richard Nornhold, PE

 

[MacGyverS2000]

My favorite DQ quote was him standing in front of a large crowd in Latin America and says, "It's times like these I wish I had studied Latin harder in high school..." What a moron

Some of the higher quality/efficiency LEDs on the market the last couple of years are very low power. A 2-3mA draw makes them uncomfortably bright, so if you're willing to pulse them for short current draws, this is indeed a workable project.

The last several years has seen "body" powered items, objects powered by the typical movement of a person as they go about their daily life. There's enough power to keep a real-time clock going, as well as an LCD display. Don't have the time to Google right now, but that would be a good thing to look for. I don't remember if it was typically piezo or magnet/coil setup. If a body can create enough power for that, I see no reason why an engine can't light an LED.


Dan - Owner

http://www.Hi-TecDesigns.com

 

[nornrich]

All,

Sorry I didn't check back sooner. I've allowed there to be discontent among the masses by not answering questions. This is not a school project. One of the areas my company is involved in is consumer product development. We see a lot of strange ideas and some that you figure would never sell, sell like crazy. We are working with a motorcycle aftermarket parts company on a design for a lighted LED foot peg. One of the requirements was that this unit would be a direct replacement for the existing foot peg. This means they don't won't the customer to have to run wires back to the electrical harness and/or battery. We starting kicking around ideas and one of them that came up was similar to the faraday flashlights that are now on the market. This is the concept we are trying to implement, but a couple of questions came to mind and that's why I turned to the experts.

Yesterday we went out and bought one of the flashlights (very expensive $20) to take apart and experiment. The answer to the question is that you can generate enough power to charge two 3V batteries in series and light the LED. The problem is that you need at least 1.5" of actuation on the permenant magnet. We haven't ruled out this concept, but we are looking at using a small air scoop and using a rotary vane to provide the needed power.

Thank you all for your feedback and I apologize for creating a potentially unending thread with my eye catching "Potato" subject.

Regards,

Rich....


Richard Nornhold, PE

 

[zeitghost]

I recently encountered an arts student who was using potato batteries to light leds.

At last count she had about 20lbs of less than fresh potatos (or potatoes) lighting several dozen leds.

I forget exactly what the object of the exercise was, since it was artistic & I'm a rude mechanical as it were.

 

[Comcokid]

You are not going to get the energy you need from a piezo to light LEDs continuously. Just look at the flashlight - mass/distance/velocity of that magnet through the coils to charge a supercap, and how long you have to shake it to charge it up. Now think of the mass of the piezo lever (a few grams) and the vibration distance (a couple of millimeters) and the efficiency of an inexpensive piezo - a no-go approach.

"Parasitic power" or "Power Harvesters" are being investigated for all sorts of sensor and low-power RF applications. However, due to the limited power nature of such devices, the applications are very limited, and very specific to the application.

Put an AA battery in the footpeg. Use the piezo (or other vibration sensing device) to detect when the motorcycle is in use. Add a small light detector to determine when not to turn of the LEDs.

 

[Warpspeed]

This all reminds me of an interesting and obscure problem I was tasked with solving many years ago.

The requirement was to develop a sensor for a personal alarm worn by a firefighter that detected body movement. If the firefighter stopped moving the thing would wail.

One of the specifications was that the sensor needed to be sensitive enough to detect slow shallow breathing (as in sleep) if desired, but the same sensor must also be robust enough to be repeatedly dropped two metres onto hard concrete without damage, or stand total continuous immersion !

I experimented with a spherical bubble with multiple internal wire whiskers and a blob of mercury. The mercury rolled around and shorted out various combinations of the sensing wires. A microcontroller with three eight bit ports, energised and sensed these whiskers. It was very sensitive to tilting or acceleration in any plane. If dropped, the mercury just splattered and reformed.

This idea was never taken up, so is free to anyone that wants it.

 

[RonShap]

Warp,
See the links below for you invention.

http://en.wikipedia.org/wiki/PASS_device

http://www.pro-am.com/Catalog/Exec/product.asp?product_id=607

http://www.usfa.dhs.gov/research/safety/nist2.shtm

 

[itsmoked]

Mercury!!! My gawd man that's the death!! You would've killed all the firemen!

I can think of a bunch of ways to sense that motion. Be hard to choose. Sleeping verses respiratory arrest... That does sound a little hard.

I saw a "Dirtiest Jobs" where they were burning down a crack house in Santa?Clara and the beepers kept going off every time they stopped to talk. Struck me as madly ridiculous. Like the solution sucked worse than the problem.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Warpspeed]

It was over twenty years ago when I was asked to look at this.

But I wonder if any of those devices would withstand several drops onto concrete without any damage or loss of sensitivity? or survive a lengthy spell totally immersed ?

The commercial units I have since seen use a mass and a piezeo ceramic wafer. Very sensitive, but also too fragile.

Yeah, mercury batteries are lethal too, hehehe.

 

[MacGyverS2000]

<sigh> It seems our (mine and nbucska?) questions about Rich's business and what services he offers were considered "personal questions" and removed. Whatever happened to getting to know the people you're helping? My replies to an engineer will be vastly different than to a marketing guy at the same company, and may change based upon the end-product, so why delete potentially useful information? Too odd...


Dan - Owner

http://www.Hi-TecDesigns.com

 

[itsmoked]

macgyvers2000; Do not take it personally. It wasn't your questions. It was nornrich's answer and only because he unknowingly made the cardinal sin...of including an email address. This is considered highly verboten!! Emails SHALL NOT be included in posts. Ever!

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[kontiki99]

If it's a gas engine why not power a small neon lamp from a coil or ignition lead using an induction pickup.

 

[itsmoked]

kontiki99; He's trying to ditch the wires on this bit of 'bling' otherwise the user won't make the buy.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[RobWard]

What do those flashing sports shoes use to power the LED?
My Godson's doesn't have provision to fit a replacement battery if that's the power source, but they might just be being treated as disposable, I suppose.

&quot;I love deadlines. I love the whooshing noise they make as they go past.&quot; Douglas Adams

 

[itsmoked]

They use batteries that go dead in about 3 months. Then ..dang! you need to buy new shoes!

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[MacGyverS2000]

3 months is about the lifetime for a pair of kids shoes, so that's fine

I've always wondered, though, about the number of battery cells (and chemicals/heavy metals) sitting in landfills specifically because people buy things to be disposable. As an LED guy, I love the shoes, but I have to ask "As an environment killer, do we really need such an item?" Maybe that makes me a hypocrite...


Dan - Owner

http://www.Hi-TecDesigns.com

 

[Mike2468]

I do not know how/if they corrected it. The LED shoes used to have a gram of mercury in them for the on/off control. Minnesota won a lawsuit with LA Gear since there was no "proper disposal plan" for the mercury. Wisconsin then passed a law prohibiting mercury as part of clothing. Illinois has outlawed mercury as well:

http://www.epa.state.il.us/mercury/mercury-illinois.html

It really is amazing what we have thrown into our landfills.