Electret Condensor Microphone

Electret Condensor Microphone

Electret Condensor 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 (which, due to the high resistance and chemical stability of the material, will not decay for hundreds of years). The name comes from electrostatic and magnet; drawing an analogy to the formation of a magnet by the alignment of magnetic domains in a piece of iron. Electrets are commonly made by first melting a suitable dielectric material such as a plastic or wax that contains polar molecules, and then allowing it to re-solidify in a powerful electrostatic field. The polar molecules of the dielectric align themselves to the direction of the electrostatic field, producing a permanent electrostatic “bias”. Modern electret microphones use PTFE plastic, either in film or solute form, to form the electret.

Where to use Electret microphone:

An Electret Condenser microphone is the most common type of transducer that is used to detect or measure sound signals. It functions exactly as the opposite of a normal speaker, that is when a sound signal is detected it produces electrical signals. So if you are looking for the transducer to convert sound signals in your environment to electrical signals to detect sound or record voices then this microphone could be the right choice for you

How to use Electret microphone:

The Electret microphone has two plates inside it just like a Capacitor the distance between the plates is directly proportional to sound present in the environment. A very basic circuit to get started with a microphone is shown below. The recommended operating voltage is 2V but it can withstand up to 10V so you can even use a 9V battery, in the circuit below I have used 5V to operate my microphone. Always remember that microphone has polarity to make sure you connect the positive (output) terminal to supply through the resistor and the ground terminal to the ground as shown in the circuit below.

The resistor R1 (10K) is used to limit the current flowing through the microphone (maximum should be 0.5mA) and the capacitor C1 (1uF) is used to filter the DC noise that might be coupled along with the analog electrical signals (output). Also, note that the capacitor is also polarity sensitive and the positive should be connected to the microphone output pin. This capacitor is rated for 20Hz to 16,000Hz so any sound waves in that range will be picked up the microphone.

Features/Specs:

• Operating Voltage: 2V to 10V
• Current consumption: 0.5mA (max)
• Microphone sensitivity 56 – 58DB
• Recommended operating voltage: 2V
• Operating Frequency: 20Hz to 16,000Hz
• Impedance: <2.2kΩ
• Low noise
• Suitable for a wide variety of Electronic products
• Multi-channel
• Frequency Range: 50Hz – 20KHz
• Microphone sensitivity 56 – 58DB
• Microphone Size:
• Length: 7mm
• Diameter: 9mm
• Weight: 2gm

Note: Product Images are shown for illustrative purposes only and may differ from actual product.