Electronic Controller
Mostly the incubators are controlled by the wafer and a switch to turning on and off the heater. There are some electronics circuit that can replace the mechanical controller like wafer and a switch. The electronics circuit that control temperature called "temperature sensor circuit". The ciruit is available in the internet but a lot of sutdy and calibration to made a one of electronics circuit that can control the temperature. The circuit is made of electronic component sensor and a transistor or IC to receive signal from the sensor and to activate the relay to turning on and of the heater. Some tempereature sensor circuit will have computation of voltage reference that means if the voltage reach the desire voltage the tendency is to give signal in circuit to cut off or to cut on the relay it depend on a connection.