Hi All,

I'm new to PiezoElectricity, I just read some article over internet & I tried to make a hobby circuit using PiezoElectric Transducer (using PiezoElectric Buzzer),

& the current is very low, but when I read one of the article in this community (https://www.askmehelpdesk.com/physic...te-630419.html), (that question thread is closed)

In which its mentioned, that they are "able to charge a 40mAh NiMH battery (they used a piezo vibrating plate) within an hour. All they used (at least shown in the paper) is a rectifier, capacitor (about 1mF) and the NiMH battery. )".

I like to ask,

1. whether i'm not using proper piezoelectric transducer (piezoelectric buzzer) i.e. how to purchase the piezoelectric transducer (as i checked online, in there technical manual, they mentioned only input voltage, current, frequency, etc. but they didn't mention the output current, voltage, etc. to force ratio.) or
2. I'm giving less force to it, as i'm pressing with thumb & finger.
3. Is there any formula for calculating the force to output current/voltage ratio.

Thanks in Advance
Ashish