# NTC thermistor heat dissapation calculation with graphs

Homework Statement
The attached graph_1 represents the resistance R of a specific NTC thermistor as a function of its temperature ϑ. In the attached graph_2, the heat dissapation P of the thermistor at room temperature of 22 ˚C is displayed as a function of temperature of the thermistor.

Determine the maximum voltage that may be applied to the thermistor to prevent it from heating up above 65 ˚C!

Assume that the thermistor is initially at room temperature.
Relevant Equations
heat dissapation
I couldn't solve this problem. Any tips or help would be appreciated. If I am violating against any rules please comment, as this is my second post :-).

#### Attachments

Homework Statement:: The attached graph_1 represents the resistance R of a specific NTC thermistor as a function of its temperature ϑ. In the attached graph_2, the heat dissapation P of the thermistor at room temperature of 22 ˚C is displayed as a function of temperature of the thermistor.

Determine the maximum voltage that may be applied to the thermistor to prevent it from heating up above 65 ˚C!

Assume that the thermistor is initially at room temperature.
Relevant Equations:: heat dissapation

I couldn't solve this problem. Any tips or help would be appreciated. If I am violating against any rules please comment, as this is my second post :-).
Both graphs have Temperature on the horizontal axis. Draw vertical lines on the two graphs at 65C -- What two datapoints does that give you? How can you then use those two datapoints to determine the maximum applied voltage? • The graph reveals that the power dissapated must be about 320 mW. The resistance at 65°C is about 115 Ω. Now we can simply plug in these values: $$V²=P*R⇒V=√PR⇒V=√36.8≈6V$$
• Thanks a lot for your help! • 