Author Message
 joepierson
 Posted: Jul 31, 2007 - 11:58 PM
 Joined: Jun 27, 2006 Posts: 115
 Anybody up on the most efficient ways to convert mechanical to electrical energy to power a pico power AVR? With running current in the uamps I suppose it wouldn't be too hard. How do those "shake" flashlights work? Could the energy be dumped into a super cap? Anybody know what the basic equation are that I need to use to figure out the conversions for, say, some type of body movement to watt-seconds?

 bloody-orc
 Posted: Aug 01, 2007 - 12:04 AM
 Joined: Dec 17, 2005 Posts: 1498 Location: Europe- Estonia- Tallinn
 what kind of mechanical energy do you have? shake? rotation? linear? It's actually all about magnets and coils the easiest I could think of is DC motor connected to a prop (like a plane has) and just apply wind.

 bobgardner
 Posted: Aug 01, 2007 - 12:21 AM
 Joined: Sep 04, 2002 Posts: 21253 Location: Orlando Florida
 How about a couple of those Honeywell furnace thermopiles that sit in the pilot light and put out 2V to hold the pilot valve open. One or two of those and a fresnel lense and a sunny parking lot? _________________Imagecraft compiler user

 nanovate
 Posted: Aug 01, 2007 - 12:46 AM
 Joined: Jan 06, 2007 Posts: 374
 There are also piezoelectrics. Quote: Anybody know what the basic equation are that I need to use to figure out the conversions for, say, some type of body movement to watt-seconds? It would depend on how you are generating/harvesting the energy. This might be of interest: http://peswiki.com/energy/Directory:Ocean_Wave_Energy

 joepierson
 Posted: Aug 01, 2007 - 12:53 AM
 Joined: Jun 27, 2006 Posts: 115
 bloody-orc wrote: what kind of mechanical energy do you have? shake? rotation? linear? It's actually all about magnets and coils the easiest I could think of is DC motor connected to a prop (like a plane has) and just apply wind. The mechanical energy I have is sports motions, like swinging a tennis racket, or golf swing, the AVR only needs to work 10 seconds or so per motion.

 valusoft
 Posted: Aug 01, 2007 - 12:56 AM
 Joined: Jul 02, 2005 Posts: 5933 Location: Melbourne, Australia
 joepierson wrote: I need to use to figure out the conversions for, say, some type of body movement to watt-seconds? Propellor hat and convert the rotary motion into electricity. I think that there is a photo of the early production units at ... http://www.geekculture.com/geekcultures ... /caps.html _________________Ross McKenzie ValuSoft Melbourne Australia

 joepierson
 Posted: Aug 01, 2007 - 01:03 AM
 Joined: Jun 27, 2006 Posts: 115
 nanovate wrote: There are also piezoelectrics. Quote: Anybody know what the basic equation are that I need to use to figure out the conversions for, say, some type of body movement to watt-seconds? It would depend on how you are generating/harvesting the energy. This might be of interest: http://peswiki.com/energy/Directory:Ocean_Wave_Energy thanks! that is the type of info I was looking for

 smileymicros
 Posted: Aug 01, 2007 - 01:59 AM
 Joined: Nov 17, 2004 Posts: 6137 Location: Great Smokey Mountains.
 Shakemote: A Battery-less Muscle-Powered Minimal TV Remote www.circuitcellar.com/avr2006/winners/D ... stract.pdf And it uses an AVR. Smiley _________________FREE TUTORIAL: 'Quick Start Guide for Using the WinAVR C Compiler with ATMEL's AVR Butterfly' AVAILABLE AT: http://www.smileymicros.com

 sbaugustine
 Posted: Aug 01, 2007 - 02:54 AM
 Joined: Aug 10, 2003 Posts: 14
 You can also use thermoelectrics to generate current. This relies on a temperature gradient being present, but that gradient could easily be established by, say, body heat transferred to the outer surface of a grip. Problem here is cost and the fact that your golf club won't work in Arizona or Florida. For an electromechanical solution, consider using rotational instead of linear stator/coil displacement. For the target device you mentioned (raquets, clubs), the shift in center-of-mass that will occur as the stator of a linear "shake generator" slides across its throw will most likely be perceived as an annoyance by the user. A rotational generator (rotation induced by the inertia of an offset mass) would still modify center-of-mass, but the absolute displacement could be made smaller. Other sources: wind, solar. I know you wanted to use mechanical energy, but unless your application will spend its life in darkness, a small, discreet solar cell might be sufficient.

 bobgardner
 Posted: Aug 01, 2007 - 03:04 AM
 Joined: Sep 04, 2002 Posts: 21253 Location: Orlando Florida
 1 horsepower = 746 watts = 550 ft-lbs per sec or 33000 ft-lb per minute. So if you lift up a 55lb bag of stuff onto a 1 ft pallette every sec, you are putting out 1/10th HP. If you spin an alternator on an exercise bike, you can put out 100 watts for a while, or a shorter burst for less than a while. I hear Lance Armstring can hump out 600 watts for hours. So if you can work a shovel at 100 watts for 10 hrs, thats a KW-hr. Worth 15 cents. Think Americans get paid too much? _________________Imagecraft compiler user

 benedict
 Posted: Aug 01, 2007 - 03:04 AM
 Joined: Sep 11, 2006 Posts: 163 Location: Kamuela, HI
 My guess is sbaugustine's solar cell approach would also be the easiest to arrange. Almost everything I've seen that converts mechanical motion into electricity is, at some level, bulky. See what kind of power output you get off of a thin film flexible cell in the environment you expect to use this in, and size accordingly. Then see if you can make something that'll convert motion into electricity with the same kind of specs for that size/weight or less. It'll be tough. Lots of vendors out there for thin film solar cells, so I won't go into a list. A quick Google search would give you dozens of vendors. Tom

 valusoft
 Posted: Aug 01, 2007 - 03:21 AM
 Joined: Jul 02, 2005 Posts: 5933 Location: Melbourne, Australia
 bobgardner wrote: So if you can work a shovel at 100 watts for 10 hrs, thats a KW-hr. Worth 15 cents. Think Americans get paid too much? And for those us disconnected from any manual form of paid labour, what is the 3 watts dissipated by the brain worth? Thanks for the reality check.... _________________Ross McKenzie ValuSoft Melbourne Australia

 bobgardner
 Posted: Aug 01, 2007 - 05:27 AM
 Joined: Sep 04, 2002 Posts: 21253 Location: Orlando Florida
 Good question. Is the guy that does the brain work more important to the project than the guy working the shovel? If its a 2 man job, they both better show up for work. One cant get along with out the other. One of em knows where to put the hole and how deep, the other knows how to make that happen. If you have a programmer and a machinist working on a widget that has a metal box and a microcontroller, which one can you do without? So should they both be paid the same? _________________Imagecraft compiler user

 Display posts from previous:  All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First
 Jump to: Select a forum Forum index|--[AVR (8-bit) Technical Forums]|   |-- AVR forum|   |-- XMEGA forum|   |-- AVR Wireless forum|   |-- AVR GCC forum|   |-- AVR Studio 5 and Atmel Studio 6 forum|   |-- AVR studio 4 forum|   |-- AVRfreaks Academy forum|   |-- AVR Tutorials|--[AVR Software Framework]|   |-- AVR Software Framework|--[AVR32 (32-bit) Technical Forums]|   |-- AVR32 Linux Forum|   |-- AVR32 General (standalone)|   |-- AVR32 Software Tools|   |-- AVR32 Hardware|--[General Electronics Technical Forums]|   |-- General Electronics|   |-- Atmel Security Products|--[Non-technical forums]|   |-- AVRfreaks.net Housekeeping|--[Non-topical forums]|   |-- Off-topic forum|   |-- AVRfreaks Trading Post
All times are GMT + 1 Hour