A buzzer is a small electronic device that produces sound when powered. It is commonly used in alarms, notifications, and indicators in various electronic projects. There are two main types of buzzers: Active Buzzer and Passive Buzzer.
Active vs Passive Buzzer
The main difference between an active and a passive buzzer lies in how they generate sound.
Active Buzzer has as a built-in oscillating circuit, meaning it only needs a DC voltage (e.g., 5V or 3.3V) to produce a sound. It is easier to use since you just turn it on/off with a simple HIGH/LOW signal. You cannot change the frequency or tone of the sound; it produces a fixed tone.
Passive Buzzer requires an external signal (PWM) to generate sound since it does not have an internal oscillator. It allows for different frequencies, meaning you can generate different tones and even play melodies.
How to Identify Them
The Active and Passive Buzzers look identical, except that the Active Buzzer has a sticker on top. This sticker is used to prevent moisture or dirt from entering the buzzer during manufacturing and shipping. It should be removed before use, as leaving it on will result in a very low sound volume.
- Active buzzer: When connected to power, it beeps continuously.
- Passive buzzer: When connected to power, it stays silent unless given a signal.
How to Choice
If you need simple on/off beeps, use an active buzzer.
If you need to generate different tones or melodies, use a passive buzzer.
