Piezos as inputs

[willtucker]

I recently found that piezos can be used as an input device because when they vibrate they create an output. However, this is not a big voltage (about 1/2 a volt). Are there any circuits that are easy to make and that will amplify this voltage? thanks will

 

[Sebi]

This voltage depend from mechanical shocking, about 10...300mV.
The amp.desingn depend from desired application.