/diy/ - Do It Yourself

>>1223151

the vast majority of piezo buzzers have 2 wires and need a pulse waveform at approx the resonant frequency of the element.
those that work directly from a DC voltage always have 3 wires (like pic) and a small circuit inside to generate the pulses. these are a minority so check the specs well.

also, it's odd that you'd be looking to buy one of these coz you probably have a dozen useless gadgets at home from which you could pull one.