- 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".