Passive buzzer 5V

A passive buzzer does not have a built-in oscillator, so it needs an AC audio signal to produce sound. It will make a "click" sound (like a relay) the moment you apply DC voltage to it. Passive buzzers have the advantage that they can vary the pitch or tone of the sound. So,you need a microcontroller like an Arduino to create an audible frequency for the buzzer. This is great if you want to create a chime or melody for a buzzer. This ability to produce a range of tones makes it useful for applications like intercoms, alarms, and musical effects.