I settled on a simple circuit with 2 transistors, using the Schmidt trigger as an example.
Assembled it in a makeshift way.
There are also rectifier diodes and a capacitor on the board. The thermistor took from a broken air conditioner.
I connect to the hood. 3-speed hood, connect to the gap of one speed.
Gathered, wired wires for the relay.
Connected to the circuit.
He applied power to the circuit, adjusted everything. Next, isolated and installed in place.
For the sensor made a small hole in the grate. He is barely noticeable in the photo.
Everything works without problems. And in addition to the video about termerel.