I have to implement a circuit which is supposed to amplify an input amplitude to constant amplitude 8Vpp output even if the input amplitude is varied (0.5-5V). The input have a 6V offset and the supply voltage is 12V. I do the simulation with the program LT-Spice. I need to build an AGC for a project (LED light organ).
-Block diagram: https://ibb.co/XLSgVN0
-Here I have an approach for the circuit (https://www.analog.com/media/en/technical-documentation/application-notes/AN_934.pdf): https://ibb.co/zFTpTXk
-I also built this circuit. It's not an AGC. It works for low input (input 1V) but not for high input (e.g. 5V): https://ibb.co/mHfPC5p
-I prefer the first circuit (https://ibb.co/zFTpTXk), but it works poorly.
What do you think about an optocoupler? https://en.wikipedia.org/wiki/Automatic_gain_control
Thank you in advance for your help. I'm a newbie and I would be very grateful for every suggestion
-Block diagram: https://ibb.co/XLSgVN0
-Here I have an approach for the circuit (https://www.analog.com/media/en/technical-documentation/application-notes/AN_934.pdf): https://ibb.co/zFTpTXk
-I also built this circuit. It's not an AGC. It works for low input (input 1V) but not for high input (e.g. 5V): https://ibb.co/mHfPC5p
-I prefer the first circuit (https://ibb.co/zFTpTXk), but it works poorly.
What do you think about an optocoupler? https://en.wikipedia.org/wiki/Automatic_gain_control
Thank you in advance for your help. I'm a newbie and I would be very grateful for every suggestion