Basically there are two types of buzzers (transducers ) : The piezo type and the magnetic type.
The magnetic buzzer is driven by the electromagnetic principle, the metal diaphragm is pulled when input the current and spring back without current. The piezo buzzer generates the sound due to the piezo-effect. By driving it with square wave voltage the piezoelectric ceramic pulls the metallic diaphragm to vibrate. Comparing the two type of buzzers (transducers):
| ||Magnetic Buzzer || Piezo Buzzer |
|Operating Voltage ||1,5 - 24V (low) ||9-30V ( high) |
|Current consumption ||20-100mA (high) ||2-20mA (low) |
|Resonant Frequency ||1-3 KHz (low) ||3-6 KHz (high) |
|Sound Presssure Level ||70-120dB ||70-100dB |
|Sizes ||4-25mm (small) ||9-50mm (big) |