I have a NTC thermistor, resistance 10k. In various examples, thermistors pull either to the ground or to the VCC. The question is, is there a difference and what is safer?
\$\begingroup\$
\$\endgroup\$
1
-
\$\begingroup\$ What are you trying to achieve? \$\endgroup\$– Andy akaCommented May 24, 2019 at 11:51
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
1
The thermistor should pull to ground. My reasoning is that in the scenario where the thermistor is connected to DCVin and the thermistor is low resistance (imagine replacing with a short) if Vout were connected to a micro-controller there would be nothing limiting the current from DC Vin which could damage the input pins of the micro controller.
Having the thermistor pulling down to ground means that resistor R will always be limiting the current drawn from the power supply. Providing the microcontroller has the same ground reference as the thermistor then no damage would occur if the input pin was hard pulled down to ground
-
1\$\begingroup\$ Had the same thoughts. To protect it as well when measuring across the NTC and accidently shorting it with the measurement probes. \$\endgroup\$– HuismanCommented May 24, 2019 at 11:49