This is a circuit diagram designed for automatic temperature control. A circuit diagram is a graphical representation of an electrical circuit that employs either simple representations of parts or industry standard symbols. The use of symbols is determined by the audience that is examining the graphic. This temperature regulated relay circuit is a basic yet extremely precise thermal control circuit that may be utilized in automation applications. The circuit of the automatic temperature control fan is built around the temperature sensor AD590, followed by the operational amplifier LM324.The AD590 is a temperature sensor that converts temperature into a corresponding voltage.