Electric condenser microphone

Description

Electret Condenser Microphone (ECM) 

An Electret Condenser Microphone (ECM) is a type of highly sensitive microphone that converts sound waves into electrical signals. It is based on the principle of a capacitor microphone, where a permanently charged material known as an electret replaces the need for an external polarizing power source.

Structure:

An ECM typically consists of the following components:

• Electret Diaphragm – A thin, permanently charged film that vibrates when struck by sound waves.

• Backplate – A conductive plate positioned close to the diaphragm, forming a variable capacitor.

• FET Amplifier – A tiny Field Effect Transistor inside the microphone, used to amplify the weak signal generated by the diaphragm.

Working Principle:

When sound waves hit the electret diaphragm, it vibrates and changes the distance between the diaphragm and the backplate. This change alters the capacitance, which produces a small electrical signal. The built-in FET amplifier boosts this signal and sends it to the output.

Power Requirement:

• Typically requires a DC bias voltage ranging from 2V to 10V (often called plug-in power).

• It consumes very low power and is cost-effective.

Applications:

• Mobile phones, laptops, and headsets

• Voice recorders

• Smart devices

• Audio recording and musical instruments

Advantages:

• Compact and lightweight

• Inexpensive

• Low power consumption

• Reliable and long-lasting

Disadvantages:

• Not suitable for high-humidity or dusty environments

• Not ideal for high-end studio recordings