Buzzers can be both fun and useful in electric circuits.We’ll use them a lot in MakeCrate projects, so let’s take a look at what is going on inside a buzzer to produce sound.
The buzzer consists of an outside case with two pins to attach it to power and ground.
Inside is a piezo element, which consists of a central ceramic disc surrounded by a metal (often bronze)vibration disc.
When current is applied to the buzzer it causes the ceramic disk to contract or expand. Changing the This then causes the surrounding disc to vibrate. That’s the sound that you hear. By changing the frequency of the buzzer, the speed of the vibrations changes, which changes the pitch of the resulting sound.