A Pendulum should really work

[Low-Q]

I think if you talked to Matt about the bouncer, you would be very surprised by the energy it produces. I have met with him in person, and have been following his progress for a while. He is not the only one going down this path. I don't believe he would claim overunity, but he gets quite a bit from the coil collapse and the unusual rotation doesn't use as much energy as a standard rotating wheel, from what I understand. I could be wrong. With the addition of the voltage produced by piezos, it might be very interesting. I am going to mention it to him as well.

I would think that a "standard" rotary generator found in most power plants are still the most efficient, most maintenance free, with respect to the energy input requirements - wind, waterfall, waves, steam etc.
But making energy by applying force alone seems to be more interesting since there is allmost no deformation in a chrystal when force are applied - as mentioned 1N force on a 1cm^3 quartz chrystal compress it by approx 1.4nm. Imagine a piezotransducer with 0.2mm thickness and 1cm^2, and apply 1000N of force, the compression is not more than 0.28um (Which is 1000N x 0.28um = 0.28mJ), but the energy output is capable of more than 0.28mJ. So I think it is a good idea to mention the piezoelectric devices to your friend. Let him leave the bouncing machine, and go for a more "silent" generator

[DreamThinkBuild]

Hi Vidar,

I missed this, I don't seem to always get notification that a topic has been replied to.

Then the energy we get out from the piezos can run a small brush-less motor which rotate the rotor

It might be possible with a more powerful piezo element. That would be a good idea hook the piezo up to it's own pulse coil to push itself from a fixed magnet to the next piezo element. A piezo pulse motor.

I'm getting low voltage when rolling, it could be also the piezo speaker I'm using is low quality also. I hooked it to a LED and wasn't able to light it by hitting on the piezo with a small tack hammer. 

[conradelektro]

It might be possible with a more powerful piezo element.

I am in the middle of building a hybrid of a pendulum and an imbalanced wheel (it is a pendulum when you do not drive it over 360°), and I did some tests and some reading about piezo elements:

---  There are no "powerful piezo elements", we are always getting only µWatts. ---

What I try is to stack many piezo elements and to use their combined output (see the circuit with the many diodes further up in this thread).

But I found that stacking has its limits, because the "mechanical pulse" that made the top element in the stack create some electricity becomes weaker when travelling down the stack. (The piezo elements themselves dampen the hit on the top one.)

May be three elements in a stack is still a useful setup, therefore I want to use many "three element stacks". I am not sure yet, whether stacking is really helping, may be many single-piezo-elements is the better strategy? The trick is to distribute a "hit" over many piezo elements.

First of all I want to come up with a drive for the pendulum/wheel that needs only Microwatts, which might not be possible. I hope that "gravity assists" and that the drive only has to overcome friction in the single bearing and air drag.

The people who built "Bedini Pendulums" needed many Milliwatts (about a thousand times more than I intend to use).

So, first a very low power drive and then many three-piezo-element-stacks or many single-piezo-elements.

Greetings, Conrad

P.S.: At least I get a very low power pendulum out of it (a device to calm your nerves or to drive you crazy, whatever your mental disposition).

[onthecuttingedge2010]

what you want is a large surface area Piezoelectric flat transducer, not stacked. just volume. if you could make your own you could make some pretty big ones with good surface volume. surface area is very important here.

[onthecuttingedge2010]

can you imagine a Piezoelectric Transducer the size of a big Gong?