Automatics for cooker hood

It's a good solution for those who want the cooker hood to run independently, but don't have any steam sensor nor timer built in their cooker hood.
Parts of the system:

• motor control relay system
• lighting relay system
• control panel (outside the hood, because it may have original control switches in not very accessible place, so the panel has to be away what gives more convenience)
• power supply 12V
• two temperature sensors DS18b20

The use of two temperature sensor gives a big advantage. One of them is placed in the hood, the second - in the panel, which gives an opportunity to measure the temperature in two places at once: above the cooker and in the panel, which is also equipped with a sensor that calculates the difference between those two temperature measurements. Depend on how big the difference is, the processor can switch on one of three ventilator's speeds by sending an appropriate command to the motor control relay system.
When the temperature above the hood starts to decrease and compensate with the temperature of the panel, the speed of ventilator decrease until they stop.
The panel has three control buttons: lighting, speed up/speed down when manually controlled and auto-standby. In auto function, the system work is excellent. About 10 seconds after setting the kettle with water, the ventilator switches on and it's automatically switched off after boiling.
A little time was needed to drive the entire system. That is why the panel has a connector, to which the temperature display can be connected. That allows to watch the temperature continuously.





Link to original thread (useful attachment) – Automatyka wyciągu kuchennego

That's interesting, I didn't know you could do that with cooker hoods.