I have a device with a built-in piezo speaker, but I'd like to get a
regular "line out" or normal speaker output from it and see if the
sound quality improves because of that.
How do I do that?
Hello,
Yes, the pietzo is a high voltage - low current device, as opposed
to a speaker which is a low voltage - high current device. What
you need is one transistor to boost up your current. You can use
a simple npn transistor, connect the collector to vcc, base to
your pietzo, speaker to emitter, other side of speaker to gnd.
seperate the base from the other stage with a 1uF capacitor,
connect a trimmer from the base to vcc. Then use the trimmer
to adjust the emitter dc voltage to be vcc/2. This should give you
a pritty loud output from an 8ohm speaker.