Good day:
I don't know how to word these properly. I'm really confused right now. I'll try. If I were to design a single supply constant volume control opamp circuit, would it be right to assume the following:
- In coming up with a conceptual block diagram, I take a sample of the input signal and compare it to some threshold value. If the signal is not equal to the threshold value then change the gain so that it becomes equal to the threshold value. However, I'm not sure if this is a valid assumption, since I would need to have a very fast opamp for the gain to change instantaneously before the next instantaneous input. I guess for audio inputs most opamp would be fast enough to change the gain.
- The VCA that I have has its gained controlled by two voltages via the following relationships: Vcn+ - Vcn-. I was thinking of setting Vcn- at a fixed voltage, and use Vcn+ for the controlling voltage.
- For threshold circuit, I was thinking of using a differentiator. The output of this differentiator would be sent to another opamp circuit with an output voltage reference to a value equal to Vcn-. The output of this opamp would be connected to Vcn+.