http://focus.ti.com/lit/an/slua017/slua017.pdf

Page 7 and 8 discuss setting the temperature thresholds and they give two equations for solving RT1 and RT2. If my memory holds then that means I have two variables and two equations so I should be able to solve these simultaneously however I am pretty sure I broke a bunch of the rules because when I tried to substitute in my one equation into the other I ended up cancelling out the term I was trying to solve for. Can someone help me figure this out.

Vcc is 5 volts

Rltf is 27445 ohms at 0 degrees C

Rhtf is 4911 ohms at 45 degrees C

I got those numbers from using a 10K thermistor at 25 degrees celsius with a B-constant of 3380K.

I am very new to thermistors (electronics in general) so hopefully I did those calculations correctly. This is the one I was going to use:

http://www.mouser.com/Search/Produc...tualkey64800000virtualkey81-NXFT15XH103FA2B00