Electret Microphone Circuit

This is the basic electret microphone powering circuit which you can use as generic reference when receivign circuits which use electret microphones.

Electret microphone circuit.

The putput impedance is determined by r1 and r2. The electret microphone test circuit schematic is shown below. How electret microphones work. Electret microphone amplifier circuit.

2 the test circuit for an electret microphone the electret microphone jfet amplifier has the gate connected to a pick up plate which is pushed back and forth by the air the source is connected to the ground and the drain is connected to the output pin. This electret has a fixed charge c and is embedded between the two electrodes. This article describes an compact electret microphone amplifier but you can connect dynamic microphones with low resistance. Since the microphone port of a computer provides about 2 3v of power this will perfectly power the electret microphone.

Electret microphones can be inserted in the same box with the amplifier it only need 5 to 10v or 9v battery with a current consumption of just 1 5ma. As stated the microphone needs power in order to operate. If you leave out r2 the output impedance is roughly the resistance of r2. This electret microphone in particular needs 2 2v of power in order to operate.

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. The circuit starts with the electret microphone.