Clarification regarding the thermistor

[dyaner]

For a thermistor, when the temperature goes up, what happens to the resistance? What is the effect on the voltage?


I was just doing a practice exam paper before and read a question on the thermistor. Referred to my cheat sheet then I got confused.

[samuch]

they give you a graph from which you can tell if the resistance goes up and if it goes up then the voltage drop across it will increase

[Stroodle]

Depends on if it's a negative or positive coefficient thermistor. The resistance of negative coefficient thermistors decreases with increasing temperature. In regards to voltage, if it's in a voltage divider, it depends where it's placed.

[superflya]

u could get a nct or a pct so be careful.

[dyaner]

Ah! I asked my teacher if we needed to know the positive and negative coefficient thermistor, she said 'No, just thermistors.' I think I should start studying that section. Thanks for the help, guys!

[appianway]

Ah, it's interesting to think about how the thermistors work.

For thermistors which have higher currents at higher temperatures (excuse the massive simplification):

The thermistors are composed of semiconductors. As the temperature increases, so does the proportion of electrons with a large enough energy to be 'conducted'. So it's all to do with the number of electrons at certain energy levels.