From Diodes comes a piezoelectric sounder driver with charge pumps and power stage. Called PAM8904, it drives sounders at up to 18Vp-p from a 3V power supply. “Bringing higher volume with a 20Hz to ...

The cheap piezo sounder disks will also generate electricity if you bend them and also have a resonant frequency, but here they are not being mounted in a way that causes them to do that and are ...