Automatic Volume Control in software

[DigitalDj]

Automatic Volume Control

I am looking for a schematic for a Automatic Volume Control circuit that i can hook the audio output from the computer to a color organ circuit. Iwant to do this so as i change the volume the lighting effect doesn't change!

Can someone help me out?
Thanks,
Kevin

 

[XNOX_Rambo]

Re: Automatic Volume Control

You can try this one: http://home.planet.nl/~heuve345/electronics/course/lesson24.html

 

[DigitalDj]

Re: Automatic Volume Control

Thanks!

1 question why do they have the - lead fron the U2 portion of the chip come up across the 100k resistor like they do?

Thanks,
Kevin

 

[flatulent]

Re: Automatic Volume Control

This is the European symbol for a variable tapped resistor. This changes the gain of the operational amplifier circuit. Another symbol would be a zig zag line for the resistive portion and an arrow touching the zig zag for the variable tap.

 

[DigitalDj]

Re: Automatic Volume Control

Ok! just a potentiometer! I had never seen this symbol before.

Thanks for the help!
Kevin

Added after 11 minutes:

Ok! just a potentiometer! I had never seen this symbol before.

Thanks for the help!
Kevin

Added after 31 minutes:

Does anybody know if there is a direct replacement for this chip with just a single supply voltage instead of the split +/- supply?

Thanks,
Kevin

 

[IanP]

Re: Automatic Volume Control

For circuits like this you can use the popular LM358 dual-opamp, or other option will be LM324 (quad) and then you will replace all 3 opamps with this one.
Regards,
IanP

 

[ragabs]

Automatic Volume Control

u can use any variable gain amplifier and control its gain using peak detector of the output voltge.

 

[DigitalDj]

Re: Automatic Volume Control

What do you mean peak detector?

Kevin