Hi everybody

I'm going to measure a surface temperature with pt100. what I got from this sensor is that, its resistance varies with the temperature. and the "100" stands for 100 \(\Omega\)resistance in 0 degrees. and should have a current source to transform the resistance to a voltage and feed this to uC adc. (10bit)

my problem is how to design current source ? would it be right to use current source ICs ? and how much big should be that current ?

please help me in any useful information about driving and running this sensor .

thank you

 

Here is something I did years ago: (never throw anything away). Stare at it for a while, and come back if there is something you dont understand.

 

one here for an Arduino..

 

one here for an Arduino..

I question why, in that circuit, they start with the bridge unbalanced?

 

I question why, in that circuit, they start with the bridge unbalanced?

Maybe starting at a different temperature than yours, alter the bridge resistors to suit your design