mechanical energy to electrical energy

dear folks,
can anyone help me out in providing a simple circuit which converts mechanical energy to electrical energy which may be large enough to drive an audio amplifier or a radio.

the question you asked is concerned with the generator action which converts mechanical energy to electrical energy. but the main question is, what is the mechanical source thet you have????????
and the direction of motion of that source is it rotary or axial????????

please clarify your question to help us helping you.

thanks wlhsaso,
mechanical energy is supplied manually by keying just like the small children toys.the energy stored during the keying must be used to generate the electrical energy to drive an audio amplifier or a radio.i think the energy provided by keying may be used to drive some gear mechanism which might then be used to generate electrical energy.

in a simple way, electronic toys is separated in two categories the first is like you said the mechanical energy is supplied manually by keying but the second depends on a battery that drives somewhat of small motor.
you may use that motor in the reverse direction (using some gear mechanism to tie the motor axe with the axe of the keying mechanism so the motor will work in this case as agenerator) and the power output may be used in any application.
but you have to take into consideration that this power is so small and it will die fast as the keying mechanism stops.
you may test this if you get a small lamp and connected it to the electrc terminals of the motor and try to rotate its axe manually by your fingers.

you can buy a cheep windup radio and scavange the wider from it

this is used to partly run the lamp + charge the battery

the battery uses a dc to dc converter
to run a bright set of leds also as a lamp as well as the radio

and the battery inside is two cells 3.0v total 1.5 each
but not in series instead the load is shared accross a network
with the -ve and +ve needed by the converter

it is in an epoxy block and has no makers name or markings
{looks factory made}
so i guess this is the
bit of it thats a little harder to backward engineer

however dosnt stop it giving up to 1amp at 12volts
enough for quite a lot

the winding mech is main spring based
and easily replaced by a wind assisted drive or another 6v dc motor

i found it in maplin electronics here in the uk

look around youll find them in the local electroincs hardware shops
like maplin

take a look at there site you may be able to find this
www.maplin.co.uk