Piezo Buzzer Definition

Piezo Buzzer Definition – What are Buzzers and Sounders?



Alan Butcher Components has been supplying buzzers and sounders for over 30 years.  The terminology for these devices can sometimes be confusing so below is a summary of how we define our audio products.


Buzzers and Sounders are also known as audio alarms, audio indicators, audio transducers, piezo buzzers, beepers and/or audible alarms.


They can be split into piezo and electro mechanical devices.


Piezo – piezo sounders contain a piezo electric vibration plate (also known as a piezo element) within a moulded case.  Sound is emitted when a voltage is applied and the piezo element inside the case vibrates.


Electro mechanical –  electro mechanical buzzers use an electro magnet and bare metal disc.  When a voltage is applied a magnetic field is generated, causing the magnet to move and the diaphragm to vibrate, generating an audible sound.


The key differences between piezo and electro mechanical are:


  Piezo Electro Mechanical
Operating voltage range 3V-250V 1.5V-30V
Current consumption Usually less than 30mA Up to 100mA
Rated Frequency Higher Lower
Sound Output Generally higher Generally lower


Piezo buzzers generally use less current, have a higher sound output and wider operating voltage.  However, electro-magnetic buzzers are capable of producing sound at low frequencies in small, compact housings.


Buzzers and Sounders can also be split into Audio Indicators and Audio Transducers:


  • Audio indicators – these devices generate sound just by applying a DC voltage. They are self-generating ie. they have internal drive circuits with pre-programmed tones.  This offers a simple solution for design engineers. Loud Piezo Buzzers, 95dB - ABI-003-RC
  • Audio transducers – these are driven using AC voltage (a wave signal) and require additional circuitry to produce a sound. These devices offer greater flexibility in terms of the range of sound output, however, the need to design a circuit can make the design process more complex for engineers.

Piezo Buzzer With Leads - ABT-450-RC


When selecting an audible device for your application, there are a number of key considerations:

  • The size of your product – how much room is there for the buzzer?
  • How the buzzer will be mounted – leads, PCB pins, panel mount or surface mount?
  • Will the device be driven using AC or DC voltage?
  • What volume do you require for the sound output?


Designers should also consider the frequency range, current consumption and rated voltage of the sounder.


There are many types of applications which use buzzers, typically for alarm or identification purposes.  These include:


  • Security and safety products
  • Portable devices
  • Medical equipment
  • Remote monitoring systems
  • Timers
  • Household appliances
  • Measurement and flow instruments
  • Weighing machines
  • User input recognition


As you have probably noticed, piezo buzzer definition varies slightly between companies, suppliers and engineers. The team at Alan Butcher Components is here to assist you with any questions you may have.  Call us on 01258 456360 or email sales@abcomponents.co.uk