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
Joined: Wed Jul 06, 2005
Thanks for the