What Is Electret Condenser Microphone?

An electret microphone is a type of electrostatic capacitor-based microphone, which eliminates the need for a polarizing power supply by using a permanently charged material. An electret is a stable dielectric material with a permanently embedded static electric dipole moment.

How does an electret condenser microphone work?

The working principle of an electret condenser microphone is that the diaphragm acts as one plate of a capacitor. Vibrations produce changes in the distance between the diaphragm and the back plate. ... This change in voltage is amplified by the FET and the audio signal appears at the output, after a dc-blocking capacitor.

What is the difference between electret and condenser microphone?

The difference between the two is that the DC-biased condenser requires an external power supply to provide polarizing voltage while the electret condenser uses a pre-polarized diaphragm or back plate. Most condenser microphones used today are electret.