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balajisu Post subject: How does a microphone work? - Comments welcome
Posted: Wed Aug 30, 2006 5:33 pm Captain Joined:
Wed Jul 06, 2005 5:54 pm Posts: 24 Location: Germantown,MD
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. Top nubbage Post subject: How
Does a Microphone Work?Posted: Thu Aug 31, 2006 7:05 am General
Joined: Fri Feb 17, 2006 12:07 pm Posts: 218 Location:
London UK 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 and negative.
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. Top balajisu Post
subject: Posted: Thu Aug 31, 2006 9:58 am Captain
Joined: Wed Jul 06, 2005 5:54 pm Posts: 24 Location: Germantown,MD
Thanks for the info Posted
11/12/2012
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