So I have an interesting request that I've searched the internet for and have not been able to find, or been able to come up with in my head.
I have a circuit with a feedback loop that is meant to control a MOSFET. The feedback loop has a difference amplifier that outputs the difference between the current output and the desired output. Based on this, the voltage to the gate of the MOSFET should change.
In other words if the output of the system is currently 11V, and the desired output is 12V, the difference amplifier has an output of 1V, and this 1V output should somehow signal that the MOSFET gate voltage needs to increase. Similarly, if the current output is 13V, the difference amplifier would have an output of -1V, and should signal that the MOSFET gate voltage needs to decrease.
I initially tried hooking the feedback output from the difference amplifier directly, but quickly realized that wouldn't work.
Rather, I need a circuit where a + voltage causes a constant voltage increment until the feedback reaches 0, or a - voltage causes a constant voltage decrement until the feedback reaches 0. So the feedback should be a sort of specification of the rate of change to the base voltage.
In a nutshell, this is what I'm referring to:
My initial guess is that this might have to include a non-inverting amplifier, or even just a comparator comparing the feedback signal to ground, and charging of a capacitor that powers the base voltage to the MOSFET.
Came up with something, looks like this works fairly well. Still open to better suggestions though.