Piezoelectric energy recovery

[mbrownn]

Has anyone tried the recover energy from vibration?

I am collecting the igniters from piezoelectric cigarette lighters and plan to sandwich them in rubber to use them as engine mounts. This way I should be able to recover energy from the vibration of an internal combustion engine.

Just a thought.

[redrichie]

you can make them yourself. large crystals at that. I am going to try in the near future. Youtube makemagazines piezoelectric crystals. setails it step by step. Might have some real value to the forum

[Armagdn03]

A very interesting but overlooked property of piezo crystals is their radical change in conductivity when stressed (not just their energy generation).

[john_g]

Interesting that this thread has come up, and very novel idea by Mbrownn – should work. I was recently looking over the construction of crystal radios and their use of high impendence earphones. I thought that the earphones used very fine wire coils, but apparently not so, they use the piezo electric effect, so for very small current we get quite a large mechanical output. I read that putting a piezo ear phone into a horn will enable the sound to be heard across a room, so wonder if that energy from a horn(s) could be converted from a sound wave(s) to an electrical impulse?

Regards
John

[electr0n]

A few years ago i mounted 20 piezo discs around the base of a small motor, (piezos mounted upright), i soldered a "T" lever counderweighted on one side to the tops of each piezo, the motor flywheel had 8 small magnets, so the rotation would cause the piezo disks to flex upon passing a magnet.
although it didnt run by itself, the concept did yeild some mA`s....the faster it ran the worse the power out was :/ (less vibration).

I`ve often thought about a cannister filled with rochelle salt, and a length of wire running through the centre..tied to the top of a tree and the bottom to the ground with abit of tension, the trees swaying motion causing the wire to stress the salts via friction.

[SuperCaviTationIstic]

I think piezoelectric materials have the highest Q factor known.

They are starting to use peizo electric transformers in electronic devices now, and I think most laptop cold cathode flourescent backlighting is driven with them.

They work by resonating a crystal at one end (through capacitive terminals) and having an output electrode placed at the location of a standing wave on the crystal. Some are made to work in transverse mode, while others work in longitudinal!

Piezo Transformer

http://www.dtic.mil/cgi-bin/GetTRDoc...c=GetTRDoc.pdf a nice pdf about different running modes/geometries of piezoelecric transformers.

If you were to use one of these rather than a piezo with just 2 electrodes, you could input your power into a resonant system, not just a transducer.

[Shanjaq]

Does anyone know how to find the major axes of electrical polarization in a Quartz or Rochelle Salt monocrystal?

This experiment is just too crude....
Piezoelectric Crystals - Rochelle Salt Crystal 1

[mbrownn]

As an engineer I am questioning if there are more instances of overunity. For example it is generally accepted that with an internal combustion engine they are around 30 t0 40% efficient with most of the energy being lost in heat.

The question I have is when was it last measured and did they measure all the losses like the heat sound and vibration? I'm not saying that an internal combustion engine has a cop of greater than 1 but I am saying that we should always question our beliefs about how things work and experimentally test it.

Now we take our diesel generator and attach a sterling engine to the heat output, use piezoelectric mountings and we will dramatically improve efficiency.

The mechanical vibration on a diesel engine is substantial.

Just a thought

[Shanjaq]

Without any comprehensible documentation on how to determine the polarization characteristics of a piezoelectric crystal under mechanical stress, it may be necessary to try the setup in the attached image...

[dR-Green]

This thing is like a wind generator, but it uses a belt which vibrates instead of a turbine/blades.

YouTube - New Wind Power - The Wind Belt Invention

[Shanjaq]

Has anyone tried applying the "Bedini Mechanical Oscillator" principle with a Piezo element in place of a flywheel? Frequency would be pretty high, so the recovery action would be pretty substantial if you used the right capacitance value. Just a thought

[Pmwuk]

Hi guys are rochelle crystals and quartz the best two piezo crystals ? Does anyone have a list of all the piezo crystals there are ?

[b_rads]

Piezo Generator

Piezoelectric Generator Harvesting Bike Vibrations Energy to Supply Portable Devices

http://www.icrepq.com/icrepq-08/344-minazara.pdf

For sale on EBAY

[mbrownn]

Piezoelectric Generator Harvesting Bike Vibrations Energy to Supply Portable Devices

http://www.icrepq.com/icrepq-08/344-minazara.pdf

For sale on EBAY

Even though the efficiency is low this isn't a problem as most vibrations are an unwanted byproduct of work being done and as such can be counted as free