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Post subject: How does a microphone work? - Comments welcome Posted: Wed Aug 30, 2006 5:33 pm
Joined: Wed Jul 06, 2005 5:54 pm
I'm new at
designing microphone circuitry. Need some valuable tips in this regard. Microphones need supply voltage of 8V or
12 V. Would these microphones be functional if I only supply them 5 V or a lower voltage than what is required by
making sure that they draw same amount of current(using a different biasing circuit)
Any comments on
this would be much appreciated.
Post subject: How Does a Microphone Work?Posted:
Thu Aug 31, 2006 7:05 am
Joined: Fri Feb 17, 2006 12:07 pm
An electret microphone needs only about 1.5 volts to bias it.
The way to test it is apply
bias of 1.5V and ac couple the output to an audio amp or oscilloscope through a capacitor of about 1 microF.
I am not sure though what the consequences would be if you bias it with the wrong polarity ie swap positive
You often see circuits where they are fed from say 9 or 12 volts, but that is because the
voltage is available for other purposes. In effect, the circuit designer drives the element through a constant
current source: a high value resistor. But the voltage across the element needs to be only 1.5 volts or so.
Post subject: Posted: Thu Aug 31, 2006 9:58 am
Wed Jul 06, 2005 5:54 pm
Thanks for the info