Meta objective: I want to pull up a TV with a winch, when the TV is turned off. I can already move up and down the TV invoked by my controller (Arduino Nano). The physical push-sensor stops the winch automatically. Good so far.
Objective of this questions: I don't want the guest to push an extra button to make the TV go up or down. There is an indicator when the TV is used and that is the Watts that are going through the 220/230V cable to the TV. If amperage is high, I instruct the winch to let the TV down (viewing position). If it is low, I pull the TV up.
See the sketch for a general idea.
Now, I'm not an electronics engineer. My question is: 1) How can I measure the high amperage (or watt) of the 220/230V cable and give that value to my 5V-controller (Arduino Nano). With my little experience I cannot think of an electrical component that could do that. However, there certainly must be a way to detect the big difference between 300 mili watts and 75 Watts. Nice if someone could point to a real component so that I could read up on that component.
2) Can one achive my meta objective without a controller? (This is nice to know. I'm totally happy if questions 1 is answered thoroughly.)