Hello everyone: Wasn't sure where to put this post so I put it here. Just wanted to say hi to the forum and I'm happy to be part of it. as for my question, would anyone know how I can test an "Electret" mic to hear if it's working properly? Thanks for you time and, glad to be here.
Hi cmradio: Thank you for the reply, the electret mic I have is a two pin type, I do have a three pin type. As for the pin out for both, this I do not have. About the amplifier, would this be a special type or could I use a mic tester instead and then configure the pin outs to use on the tester?
On the two pin, one of the pins will likely have a trace to the case... this will be the ground.
To the other pin, solder a 10K resistor and that goes to a 9V battery (try 3.3K if you're using 3V with a coin cell or 2 x "AAA" or something). The side of the resistor that is soldered to the microphone, place a 2.2 to 4.7uF capacitor with the "+" side toward the microphone. Run the output of that capacitor to an amplifier input.
Unlike dynamic microphones, electrets will have enough output to drive a headphone or even a HiFi amp enough for testing to see if it works.
If the your voice is clear, the polarity is correct and the mic works.
If it has a crackly output, especially on peaks, try reversing the battery.
If there's zero output and your connections are all OK, it's dead.
Usually the only thing to kill an electret is moisture - the element is permanently static charged..... unless it get put under water.
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