new icn messageflickr-free-ic3d pan white
Optical Microphone Schematic | by scanlime
Back to photostream

Optical Microphone Schematic

1. IR LED is driven at DC (No modulation in this version)

2. A high-gain transimpedance amplifier converts the photocurrent to a voltage.

3. High-pass filter to strip out the DC component and get the audio only

4. Gain stage: non-inverting amplifier with 1/2 Vcc reference voltage

5. Another high-pass capacitor, to remove the DC reference voltage.

 

More on this project at:

micah.navi.cx/2010/02/simple-optical-microphonepickup/

 

3,060 views
1 fave
0 comments
Uploaded on February 3, 2010