Thermostat, a type of temperature sensing device that maintains a controlled part within a certain temperature range by automatic open or closed circuit under normal operation, and its operating temperature is only fixed or adjustable.
A thermostat is a device that directly or indirectly controls one or more heat and cold sources to maintain the desired temperature. To achieve this function, a thermostat must have a sensitive element and a converter. The sensitive element measures the change in temperature and produces the desired effect on the converter. The converter converts the effect from the sensitive element into a function that can properly control the device that changes the temperature.