Electromechanical thermostat
Here is teardown of Stego FZK 011 thermostat. Thar is an electronechanical thermostat that can control heating resistor and/or cooling fan. The thermostat is based on bimetal strip that bends based on temperature. To get sharp transition and some hysteresis there is also magnet near silver calibration adjustment screw and electrical contacts. Components on board →