Electret Microphone Circuit

If you leave out r2 the output impedance is roughly the resistance of r2.

Electret microphone circuit.

This electret has a fixed charge c and is embedded between the two electrodes. 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 diaphragm is made of thin teflon material and is also termed as electret and hence the name electret mic. This is the basic electret microphone powering circuit which you can use as generic reference when receivign circuits which use electret microphones.

The electret microphone test circuit schematic is shown below. 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. An electret microphone mainly consists of a diaphragm a couple of electrodes and an in built jfet. As stated the microphone needs power in order to operate.

Since the microphone port of a computer provides about 2 3v of power this will perfectly power the electret microphone. The circuit starts with the electret microphone. The putput impedance is determined by r1 and r2. How electret microphones work.

This article describes an compact electret microphone amplifier but you can connect dynamic microphones with low resistance. Electret microphone amplifier circuit.