Hello. I need to create a small device, which changes temperature readings with certain tolerance(for example, increasing or decreasing with 5 degrees). Is it possible to be done by using resistor? I know resistance corresponding to different temperature but how temperature can be moved by certain degrees?
The specific here is need to work after detecting 12 volts and stop working when detects 13 volts. I don’t know what to use to achieve this. I need to test it on my car.
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Maybe you’re looking for a thermistor?
Are you saying your entire circuit should only operate at 12volts or are you talking about the temperature sensing resistor specifically?
I mean it should work when ignition is on, which means ~12.5 volts and should stop correcting when detects more than 13 volts
Hi Ron,
One option that you could look at is a micro controller such as a Raspberry Pi Pico with a voltage divider to read the analog voltage and program the logic to do what you’re wanting it to do.
Hi Ron,
You’ve got some great answers so far. A thermistor like the one that @Pixmusix recommended is likely what you are after. You could pair this with a micro like @Dan recommended or use a more analog approach with some logic gates and op amps.
On the page for this thermistor there is a how to guide for using thermistors. I can see the one that Pix linked also has a guide but it no longer works, I’ll have that updated.
Have a look at this guide in the meantime and let us know what you think!
Thanks for the links. I will check the one for raspberry pi, despite that I’m not familiar with it. I expected it will be a diy job 
I read about raspberry but honestly, it’s not something I can do. Maybe what I wrote in my first post its not easy to achieve. So I will change my requirements - is it possible to use thermistor which increases the temperature readings permanently by 2 degrees? For example - 10 will become 12, 50 will become 52 etc. Doesn’t mater if the voltage is over 13 or not? I’ve changed several temperature sensors and they always show 1 or 2 degrees lower than the real
Hey @Ron280737,
This is not really possible to do directly to the thermistor but the output from it could be modified before it is read or simply read as “Output+2” however you are reading it.
What are you feeding this temperature reading into?
This is for my car’s temperature sensor. I will use connectors to the sensor and its wiring. How I can achieve this +2 output?
Hi Ron,
What part of the car are you hooking this up to? A car manufacturer would take this offset into account or thermally bond the sensor to whatever device it has to read. Some more background on your project ought to help everyone!
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