Active Analog Temperature Sensors :
There are varieties of analog temperature sensors around us. The main function of a active analog temperature sensor IC is to provide an output as voltage which is proportional to the temperature of the surroundings. Few of them are LM34, LM35, TMP 35/36/37, MCP9071 etc. These devices does not require any external calibration. A simple ADC (Analog to Digital Conversion) required for digital processing.
Quick overview on the LM35 Analog Temperature Sensor
- Low cost, well available Analog Temperature Sensor
- Calibrated directly in ° Celsius (Centigrade)
- Linear + 10 mV/°C Scale Factor
- 0.5°C Ensured Accuracy (at +25°C)
- Rated for Full −55°C to +150°C Range
- Low Self-Heating
- Low impedance output, 0.1W for 1 mA Load
- Operates from 4 to 30 V
- Also suitable for Remote Applications
Pin Configuration : Pin 1 : +Vcc (4 to 20 V ) , Pin 2 : Output, Pin 3 : Ground (GND)
YOUR OWN DIGITAL THERMOMETER
It is very interesting to work with new things, when a primary stage of testing success brings mental satisfaction on the work & we go for more advanced implementation which increases the knowledge & allow us to think and face practical.
As LM35 is calibrated directly in ° Celsius (Centigrade), so using only a multimeter it can be used as a digital thermometer for both Basic Centigrade Temperature Sensor & Full-Range Centigrade Temperature Sensor. Fig. 1 & Fig. 2 describes the circuit for those.
The Basic one on the breadboard
Time to test!
Leave a reply if I missed anything!