Post by thread:[EE]: Gravity/motion electric generator

I think perpetual motion generators have been discussed on the list but that's not what I'm after. Propellor clocks and Olin's eyeball use transformers and slip ring contacts to transfer power to the moving part. Did some web searching but nothing came up for this: Why isn't there a simple way to convert centrifugal or centripetal force to electricity? If I can stand in the spinning barrel at the fair, the floor drops down and I'm plastered to the wall, then why can't the same force be turned into electricity in some straightforward process?

What relation is between gravity and electromagnetism ? :) Charles Craft wrote: {Quote hidden}> > I think perpetual motion generators have been discussed > on the list but that's not what I'm after. > > Propellor clocks and Olin's eyeball use transformers and > slip ring contacts to transfer power to the moving part. > > Did some web searching but nothing came up for this: > > Why isn't there a simple way to convert centrifugal or > centripetal force to electricity? > > If I can stand in the spinning barrel at the fair, the floor drops down > and I'm plastered to the wall, then why can't the same force be turned > into electricity in some straightforward process?

> Why isn't there a simple way to convert centrifugal or > centripetal force to electricity? Because force without movement does not represent energy. Also note that the big problem with (faster) rotating displays is probably as much in the balancing as in the power transfer. Using something that moves within the rotating part to get power might cause lots of balance trouble. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

> I think perpetual motion generators have been discussed > on the list but that's not what I'm after. Good, 'cause that don't work! ;-) {Quote hidden}> Propellor clocks and Olin's eyeball use transformers > and slip ring contacts to transfer power to the moving part. > Did some web searching but nothing came up for this: > > Why isn't there a simple way to convert centrifugal or > centripetal force to electricity? > If I can stand in the spinning barrel at the fair, the floor drops > down and I'm plastered to the wall, then > why can't the same force be turned into electricity in > some straightforward process? Put on your physics cap. Let's just look at units: energy = joules = (kg)(m^2)/(s^2) force = newtons = (kg)(m)/(s^2) To deliver energy, therefore, some displacement is required, in order to add the additional "m" in the denominator of the energy units to the force units. Thus, mechanical production of energy requires some displacement. This is counterintuitive: after all, if you place your hands flat on a wall and push as hard as you can, neither you nor the wall will move, but your body is obviously expending energy. Mike H.

Charles Craft wrote: > I think perpetual motion generators have been discussed on the list but that's not what I'm after. > > Propellor clocks and Olin's eyeball use transformers and slip ring contacts to transfer power to the moving part. > > Did some web searching but nothing came up for this: > > Why isn't there a simple way to convert centrifugal or centripetal force to electricity? > > If I can stand in the spinning barrel at the fair, the floor drops down and I'm plastered to the wall, then > why can't the same force be turned into electricity in some straightforward process? > > > > > work = force * distance If your spinning sphere has an infinite diameter you could use that force. -- Martin K http://wwia.org/

What I'm looking for is something to squish between me and the wall that generates electricity. A piezo crystal that generates charge not only during compression but while compressed. Came by a web site that uses a rotating device to convert the angular momentum to linear but I was hoping to find something without moving parts. %-) > > Why isn't there a simple way to convert centrifugal or > centripetal force to electricity? > If I can stand in the spinning barrel at the fair, the floor drops > down and I'm plastered to the wall, then > why can't the same force be turned into electricity in > some straightforward process? Put on your physics cap. Let's just look at units: energy = joules = (kg)(m^2)/(s^2) force = newtons = (kg)(m)/(s^2) To deliver energy, therefore, some displacement is required, in order to add the additional "m" in the denominator of the energy units to the force units. Thus, mechanical production of energy requires some displacement. This is counterintuitive: after all, if you place your hands flat on a wall and push as hard as you can, neither you nor the wall will move, but your body is obviously expending energy. Mike H.

On 6/7/05, Charles Craft <spam_OUTchuckseaTakeThisOuTmindspring.com> wrote: > What I'm looking for is something to squish between me and the wall that generates electricity. > > A piezo crystal that generates charge not only during compression but while compressed. > Let me know when you find it. That thing and a C-clamp, and I won't ever need batteries again! Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie

Charles Craft wrote: > What I'm looking for is something to squish between me and the wall > that generates electricity. > > A piezo crystal that generates charge not only during compression but > while compressed. It can't work that way. Power is force *times* motion. You have a force but no motion "while compressed", so therefore no power is being put into the crystal and power can't be taken out continously. Think about it. If you could get power out of a crystal just because it is compressed (not *being* compressed), you could clamp it in a vice and get power indefinitely. What you are looking for is called a "perpetual motion machine", "free lunch", or "hogwash". ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com

> >It can't work that way. Power is force *times* motion. You have a force >but no motion "while compressed", so therefore no power is being put into >the crystal and power can't be taken out continously. The thing that's not so obvious here, is that the energy from the compression is stored charge in the capacitance of the crystal. When you use it, you've discharged the cap. When you relax the crystal, it will generate in the other polarity, which you can dump or recover as you wish, then you have to do it again.

Not having an EE background, PICs are just a hobby and I skipped most of my physics classes in college. Wanted to make sure there wasn't an obvious item I missed in looking around. http://www.nutsvolts.com/toc_Pages/jun05toc.htm A combination of the bike spoke article above and trying to get my kid to sleep while making flashlight shadows on the ceiling led me down a path of how to put LEDs on a ceiling fan and power them from the motion of the fan blades turning. Thought about small wind powered generators and guess that's what I'll need to work on. My college physics prof never claimed to teach physics - only a class in problem solving. :-) thanks! {Original Message removed}

Well... > A combination of the bike spoke article above and trying to get my kid to sleep while making flashlight > shadows on the ceiling led me down a path of how to put LEDs on a ceiling fan and power them from > the motion of the fan blades turning. Thought about small wind powered generators and guess that's > what I'll need to work on. Oh If its on a fan, can't you put a sleeve over the spindle, hard mount it to the fan itself and use belt drive to a dc motor as a generator? O-rings work well for belts.. -- andrew

Have you ever considered how long this project would run for an hour a day on a few AA cells? Probably a long time, especially if you had it shut off automatically so it doesn't run all night. A simple mercury switch would work great in place of the on/off switch if you Shoe Goo'ed it in place tilted so that it was open when the fan is stationary but closed when the fan spins. Nothing could be simpler. If balance is a problem, put battery holders on the other blades too and use wire wrap wire to route power to your project and double (or triple) your battery life so you'll have to get on a ladder half as often. If you Shoe Goo'd the whole thing to the top of the fan no one would even see it. If AA or AAA batteries are too visible, every pack of Polaroid film comes with a nice flat battery in the base of them with tremendous capacity. --Steve Murphy

On 6/6/05, Charles Craft <.....chuckseaKILLspam@spam@mindspring.com> wrote: > If I can stand in the spinning barrel at the fair, the floor drops down and I'm plastered to the wall, then > why can't the same force be turned into electricity in some straightforward process? I've developed an apparatus to convert rotational energy to electricity... it's secret... I'll describe it after the patent goes through. Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie