Maker Pro
Maker Pro

Electret micphone, connecting to DC Offset

Hi, first time on the forum here

I got a questions in regarding electret mics. I'm building a simple
circuit for my assignment. It is to use electret mic, dc offset, amp,
filter and through STK500 kit then then to the output.

I'm trying apply DC offset to my electret mic, so I can bring the -2.5V
to 2.5V up to 0 to 5V. The problem that I'm having is that, when I put
in the DC offset into the circuit, I get nothing from the output. It's
like its been grounded. And without the dc offset, the mic works fine.
I've tried putting in an unity gain after the mic(before the offset),
the same thing happens. Please help if you can.


Circuit:

5V
----------------------------------
| |
< 2.2k < 2k
|----------||---------|------------------|LM324
amp|------|Filter|-------(STK500)--|Output circuit|
MIC <
| >2k
=== |
-- ===
----
 
J

Jasen Betts

Jan 1, 1970
0
Hi, first time on the forum here

next time use a monospaced font.
your diagram is gibberish,
I got a questions in regarding electret mics. I'm building a simple
circuit for my assignment. It is to use electret mic, dc offset, amp,
filter and through STK500 kit then then to the output.

STK500 is Atmel microcntroller thing?
I'm trying apply DC offset to my electret mic, so I can bring the -2.5V
to 2.5V up to 0 to 5V.

??? I don't think most electrets will prduce that much signal, you may need
more gain,
The problem that I'm having is that, when I put
in the DC offset into the circuit, I get nothing from the output. It's
like its been grounded. And without the dc offset, the mic works fine.
I've tried putting in an unity gain after the mic(before the offset),
the same thing happens. Please help if you can.

from what I can decypher your diagram looks mostly ok,
what's the project? digital voice recorder?
 
Top