Re: Piezoelectric Crystal. (Please Assist)

On Jun 23, 12:52=A0am, "Cwatters"
<colin.wattersNOS...@[EMAIL PROTECTED]
> wrote:
> <a_lifeless_protr...@[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 =A0AA battery when in motion , =A0using 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
rechar=
ge
> one in say 1 hour would need a power source of around 1.2 x 2700 =3D
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!

To Cwatters , thanks for your advice. really did helped me alot.