A Pendulum should really work

[lumen]

Vidar,
In a rotary design, the RPM could be increased to some resonate frequency for higher gain.

The testing I have done was on a high voltage element for a lighter and the measured compression was only about .001 inch. The disks can deflect further but they don't need much deflection for a large output. I believe this is a workable concept with the main disadvantage that they may fail over time.

[Low-Q]

Vidar,
In a rotary design, the RPM could be increased to some resonate frequency for higher gain.

The testing I have done was on a high voltage element for a lighter and the measured compression was only about .001 inch. The disks can deflect further but they don't need much deflection for a large output. I believe this is a workable concept with the main disadvantage that they may fail over time.

I think that if this works, my guess is that if something fails over time, it will already be covered by the "income" from such a design

A little rough, we can say that a modulus of elasticity of a quartz chrystal is about 70 GPa, so that compression of a 1 cm3 chrystal, will at 1 Newton force compress something like 1.4 nanometers. So there is not much compression to talk about.

Increasing the RPM will probably also increase efficiency as the electrostatic properties allows more current as the frequency increase.

Can't wait to try this out.

Vidar

[Low-Q]

A nice demonstration. It isn't much force required to ligt an LED. Ofcourse it doesn't require much energy to power an LED, but what if we apply tens of Newton, several hundered times pr. second? Should it at least be enough to run a small selfrunner?
http://www.youtube.com/watch?v=Xuw9frP1GNo&NR=1

[DreamThinkBuild]

Hi Low-Q,

I did a test with a piezo speaker through a 1/2 watt 10 ohm resistor.

The values back were between 10mv - 200mv. 200mv was obtained by dropping a 1/2" steel ball bearing on the piezo. This gives a range from low to high of 10uw - 4mw through 10ohms.

[Low-Q]

Hi Low-Q,

I did a test with a piezo speaker through a 1/2 watt 10 ohm resistor.

The values back were between 10mv - 200mv. 200mv was obtained by dropping a 1/2" steel ball bearing on the piezo. This gives a range from low to high of 10uw - 4mw through 10ohms.

That is 4mW in a very short time, but from what altitude did you drop the steel ball from?
The LED in the video above require approx 3V and a few mA. Let's say that piezo generate approx 15mW just by tapping it gently with the fingertip.

Thanks for the info DreamThinkBuild, but I now suddenly realize that the point is however not how many watt you get out, but how the energy are generated. With my preliminary knowledge about piezos, these devices does not provide a counterforce when loaded by a LED or resistor. Yes, they will resist deflection when loaded, but the mechanical interference seems not to disturb or counter the force which is applied to it in a significant way.
This means one can put some kinetic energy into the piezo generator, without actually spending energy to generate this energy, because the kinetic energy you put in seems to be equal to the kinetic energy that bounce back once the piezo has being hit.

Like dropping a steel ball on a polished solid steel plate. It will bounce for quite some time, but the loud high frequency sound it makes at each bounce appearently seems to be "excess" energy - which in a piezo will be electric energy rather than sound.

Vidar