Using the LM35 temperature sensor we can design various electronic thermometer projects that require a temperature sensor . The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature.
The LM35 electronic thermometer does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range.
Combining two simple low cost integrated circuits LM35 ( temperature sensor) and LM3914 dot / bar display driver , can be designed a very simple low cost and high efficiency LED temperature measurement system .
The LM35’s low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus supplies. As it draws only 60 μA from its supply, it has very low self-heating, less than 0.1°C in still air.
As you can see in the circuit diagram , this bargraph thermometer require few external components and .
