Electret microphone tester

Discussion in 'The Projects Forum' started by MMH, Feb 28, 2013.

  1. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Hello there everybody!! I have some electret microphones which I want to test-whether they work or not, since they are pretty old now. Can you please recommend a simple circuit with which I can test the mic? I also want to make a circuit using NE555 to which would amplify all that I will talk to the microphone- to the speaker so that I can hear my voice from the speaker.

    Thanks in advance for your help!!
     
  2. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    So, does that mean that there are no such circuits using NE555?
     
  3. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    555 is more of a switch/timer than an amplifier.

    If you have a transistor, you can test it. Electret microphones need a bias voltage, very low current at 2-5V is typically used. The output can then feed a single transistor.

    Here's a very basic circuit for an electret microphone, follow the thread for a better one.

    Install free SoundCard Scope to see the waveforms.

    I gave a bit of direction on using SoundCard Scope in This thread Just remember to include the voltage divider and diodes so you don't damage your computer sound card input.
     
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