Temperature sensor circuit indicated by LEDs indicator.
A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.
This schematic diagram come from circuit: LEDs Temperature Indicator
Go to that page to read the explanation about above circuit design.
In the electrical sector, a schematic diagram is usually used to describe the design or model of equipment. Schematic diagrams are usually utilized for the maintenance and repair of electronic and electromechanical devices / units. Original schematics were made by hand, using standardized templates or pre-printed adhesive symbols, but nowadays Electrical CAD computer software is often used.
In electronic design automation, until the 1980s schematics were virtually the only formal representation for circuits. More lately, using the progress of computer system technology, other representations were introduced and specialized computer languages were developed, because with the explosive development of the complexity of electronic circuits, classic schematics are getting less practical. As an example, hardware description languages are indispensable for contemporary digital circuit design.