Yep, your’s is servo, mine is stepper or PWM (i have both, different throttle body’s )
The automation/positioning, in my case, can be done with either return to manual defined spring ( position adjustable with a “wrench” ) or, more advanced , with a potentiometer allowing adjusting the AFR as desired from the cabin.
In shown case above, Stepper motor, the Analog 0 in, reads the voltage, 0-5V , from the Potentiometer.
The stepper follows according the voltage, the power from the stepper only set slightly higher then the return spring power in the throttle body. In the program i can modify the lenght off way for the stepper, the reaction time, the speed, and also the treshold to ignore low fluctuations.
If we determine the perfect AFR at position X, locking that mechanicaly with 2 springs ( mechanical zero )
Then the voltage from the AFR meter set ( 0-5V) will send the mixture valve in either direction as needed.
( to be build and tested before actual showing of )
If i compare with 2 analog reads , 1 from potentiometer, and another from AFR value
i can steer the Mixture valve according the Potentiometer setting.
The PWM set would be on the same basics, working on that now.
I hope to be able to split this topic into different builds/subtopics ,so things stay clear.
I will try your setup as a studycase for my learning, if i find something i will let you know.
Picture with the output voltages from the AFR set i use