I am using an LM35 sensor to measure the temperature of water. I need a signal conditioning circuit with an output of 0-5V. I will use a PIC16F877 digitally convert the signal..... I needed a circuit for my LM35 sensor with signal cond. circuit.
I am using an LM35 sensor to measure the temperature of water. I need a signal conditioning circuit with an output of 0-5V. I will use a PIC16F877 digitally convert the signal..... I needed a circuit for my LM35 sensor with signal cond. circuit.
hi,
A LM35 has an output of 10mV/Cdeg, with a basic range of +2C thru +150C. [centigrade scaling]
By adding resistors/diodes you can extend the basic range.
So for say 0 thru 100C you will get 0mV to 1Volt.
If you feed this directly into a PIC's ADC, with a +5Vref you will get an ADC value of (1/5) * 1023 = 204...
You can reduce the +Vref to +2.5Vref then the output of the ADC would be 408 for 100Cdeg.
The correct solution would be to amplify the 0 thru 1V by *5, giving a ADC value of 1023 for 100Cdeg,,,
that would give the best resolution.