T&L Publications

Hey guys<p>I need help. How on earth does the electret mic work? I have it connected as in the diagram that accompanies it, but on monitoring the output voltage, it doesn't change. How do i make this work in a circuit??<p>Here is the diagram
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">code:</font><hr><pre>
MIC---------||--- Output
| |______ V+
|__Gnd<p> </pre><hr></blockquote><p>[ February 01, 2003: Message edited by: newguy ]</p>

You hook the voltage source to the positave and negative leads and take the signal from the ground and through the capacitor to the + lead.It seems to me you are trying to operate it like an old carbon mike button.It won't change voltage like that.

Ok, i have my meter connected to the side of the cap not connected to the mic, and ground and the meter reads zero. <p>I guess the cap does not pass the dc.

right.
leave the meter the way it is and switch the meter to a.c. millivolts and it should give you a reading when you tap on it or make a noise.

You need a resister from one side of the mic to v+
Resister should be about 1k.
This is how the card shows it.
You can also use a voltage divider with a cap between the resisters.
This is the way the card shows it.
V+
R1
1------
cap ---- output<p>2 -- gnd <p>I doubt if this spacing will stay.
Connect pin 1 to 1k resister to v+
Connect pin 1 to capacitor to output
Connect pin 2 to ground (other lead)<p>Wow! What a mess when you describe a simple picture.

This should help you out a good deal:<p> R1
MIC----------/\/\/\/----------------V+
| |
| --+
| -- C1 R2
| |-------/\/\/\/---------------GND
GND |
|-----------------------------Output<p>R1: 10k
R2: 1M
C1: 100uF
V+: 9V (you can use a 9V battery)<p>Output is taken from the Output terminal, and your meter should be set to "AC" voltage.<p>~Kyle