Can anyone help me to understand piezoelectric.

[hanshen]

I am doing a project using piezoelectric to recharge a battery. Could anyone help me to understand on it, and also give me some ideas about it.

Thanks

 

[FvM]

A brief overview can be found here: Piezoelectricity - Wikipedia, the free encyclopedia
To give a short explanation of my own, a piezoelectric element can be seen as ceramic capacitor with a built-in series voltage source. Applying a force creates a proportional voltage. It appears as a current pulse at the loaded terminals of the piezo element.

 

[hanshen]

How much current pulse does it produced? if it is needed to charge a battery, i needed at least 200mA so that it is efficient.
btw, can i store the current or use current booster to amplify it?

 

[FvM]

i needed at least 200mA so that it is efficient.

- The principle answer is: it only depends on the mechanical energy supplied to the piezo transducer. What's your energy source?
- The "realistic" answer: I can't imagine a piezo energy harvesting application, that produces an output in a similar order of magnitude

can i store the current or use current booster to amplify it

The application is energy harvesting, I presume. So you won't have a power supply for a "booster".

 

[hanshen]

- The principle answer is: it only depends on the mechanical energy supplied to the piezo transducer. What's your energy source?
- The "realistic" answer: I can't imagine a piezo energy harvesting application, that produces an output in a similar order of magnitude

i try to attached it to the wireless keyboard. so that it will be able to recharge the battery while typing.

The application is energy harvesting, I presume. So you won't have a power supply for a "booster".

so how can i increase the current if the current produced is small?

 

[FvM]

Linear has presented a piezolectric energy harvesting application in the 1-10 mW power range:


They also published a list of companies, that are supplying specialized piezoelectric transducers for energy harvesting. I think, you'll find some ideas there.
**broken link removed**
Advanced Cerametrics
Mide Technology - Engineering Smart Technologies
Ceramics - Advanced Ceramics from Morgan Technical Ceramics
Smart Material Corp.

Generally energy harvesting is bound to the law of "conservation of energy". You can't get more energy than supplied to the system from the enviroment.

P.S.: From a brief review, I got the impression that all present piezo energy harvesting solutions are operating in a low mW order of magnitude. A strong source of vibrational energy is however required. In so far, it would be completely unrealistic to target a continuous output current of 200 mA for your project.

 

[hanshen]

I knw that piezoelectric produce a low power. That is reason i would like to apply it in wireless keyboard which operate in low power. By typing it would eventually store up charges and charge the battery in that keyboard as we press the keyboard buttons a lots when using computer.

So, is there any way for me to store up the charges and recharge the battery using pulse charging? This is my school project. Hope u guys can help as I not so good in this but willing to learn.