You need an actuator that takes a proportional input signal. 0-10vdc is common. You'll just need a 24vac to 10vdc power supply for the manual potentiometer.
https://cerpangha.com/products/s963b-1136-honeywell-manual-potentiometer-270a
You need an actuator that takes a proportional input signal. 0-10vdc is common. You'll just need a 24vac to 10vdc power supply for the manual potentiometer.
https://cerpangha.com/products/s963b-1136-honeywell-manual-potentiometer-270a
Thank you! I think that actuator is exactly what I need.
Nice. I don't know about the torque requirements or mounting dimensions of your existing (or new?) damper so double check those. Kinda sucks that they don't make one that takes the pot signal directly. I know a lot of lighting dimmers are 0-10v but how they are powered and interact with that damper is uncharted territory.
I know those kind of motorized vents are used in commercial HVAC. (Here’s a white paper on a stepper motor for one https://www.portescap.com/en/newsroom/whitepapers/2021/10/customized-and-reliable-stepper-motors-for-damper-applications )
A stepper would be the easiest thing because if you know it takes 10 steps to fully open from fully closed, you could keep track of how many steps you have sent each direction in Home Assistant and be able to display the current status. 
If you want a knob on the wall that controls this, I think somewhere behind it you are still going to need a control system that translates wall switch inputs into stepping logic. Home Assistant would be able to do that easily. 
Be aware that an underpowered or stuck stepper motor can "skip", causing the position data to be incorrect.
A servo motor has active feedback, so doesn't have this issue. Servos do have their own drawbacks too, so they are not always a suitable replacement.
I'm not familiar with that hardware, but unless there is an off the shelf option you are related to engineering it yourself. There would need to be a stepper in there you can control directly, and a way of programming the controller to know how many steps to take.
Home Assistant is open source home automation that puts local control and privacy first. Powered by a worldwide community of tinkerers and DIY enthusiasts. Perfect to run on a Raspberry Pi or a local server. Available for free at home-assistant.io