Hi there,
In multisim, we do not have temperature simulation and the only analysis that is available for you is the temperature sweep located at (Simulate=>Analysis=>Temperature sweep). This analysis allows you to sweep the temperature range and at a different temperature you will get different resistor values.
In addition, you can also use a Voltage_control_resistor. Instead of applying a temperature, a voltage is applied and you pretend the input voltage is temperature that control you resistor.
Here are two links might be helpful for the simulation of the PTC thermistor, they use NTC instead.
NTC Thermistor Multisim Spice Component
How do I make generic spice models work in multisim?
Regards,
Chen_T
National Instruments
