Hello, I am a complete novice and need some advice on what components to get for a small circuit with a linear actuator and proximity sensor. I want it so whenever the proximity sensor isn't detecting anything the linear actuator goes and stays up, and when the proximity sensor is detecting something the linear actuator goes and stays down. I need the proximity sensor to have a range of about 1-2 meters and the circuit to be a small as possible. I also have a relatively small budget so I do not want to be paying more than around £20-50 for all of the components. What components would I need to get and how would I make this basic circuit?