When the ambient temperature increases in the circuit that changes the motor speed according to the temperature, the resistance of NTC decreases and the current passing through the pot increases. The increase in the current passing through the pot increases the tension on this element.
Increasing the voltage of the pot increases the output voltage of the LM317 and the speed of the DA motor increases. When the ambient temperature decreases, the resistance of the NTC increases and the current passing through the pot is reduced. Reduction of the current passing through the pot reduces the tension on this element. Decrease of the output voltage decreases the output voltage of the LM317 and the number of revolutions of the DC motor decreases.