Re: Piezoelectric Crystal. (Please Assist)

<a_lifeless_protrait@[EMAIL PROTECTED]
> wrote in message 
news:aa3dcdca-3902-4cf0-8ad4-2ab349201bd9@[EMAIL PROTECTED]
> Hi to all , i'm a ME student doing my final year project, working on
> piezoelectric crystals. My plan is to produce enough electricity to
> charge up a  AA battery when in motion ,  using the piezoelectric
> crystals method. But i'm unable to purchase any or able to find any
> one yet. Is there any specific ones that u all can suggest? any place
> i could purchase it ? or even suggestions to help in my project ?

Might not be so easy...

A good AA rechargable battery has a capacity of circa 2700 mAH. To
recharge 
one in say 1 hour would need a power source of around 1.2 x 2700 = 3.2W
and 
probably more if the charge is to be "controlled"...

http://en.wikipedia.org/wiki/Piezoelectric

"DARPA's effort to harness 1-2 Watts from continuous shoe impact while 
walking were abandoned due to the impracticality and the discomfort from
the 
additional energy expended by a person wearing the shoes."

So perhaps you would need to aim for a 10 hour trickle charge? That would 
require around 0.3-0.5W assuming the battery isn't used to power anything
at 
the same time. Perhaps start by looking up the DARPA research and see if 
there is another way to do it. Crack the problem and you might be able to 
sell it to them!