Temperature Regulated Fan

1 x Fan

1 x DC Motor

11 x Popsicle Sticks

1 x Wooden plate

1 x 9V battery

1 x Switch

1 x 50K Potentiometer

1 x N Channel MOSFET

1 x Transistor Heatsink

3 x Wires

1 x 9V Battery Clip

5 x Hot Glue Sticks

1 x 10K Thermister

A fan which automatically changes the rpm depending on the ambient temperature.

Thermistor is a type of variable resistor. A thermistor is being used here to control the flow of electricity to a transistor. The resistance of a thermistor varies inversely depending on the ambient temperature. A temperature sensor-based cooling system is used in air conditioning and smart fans. Efficiency is increased based on the climate of the area the device operates in. Thermistors use metal oxides to vary their resistance based on temperature.

I have recorded my testing in the video below. During my testing, when I placed an ice cube on top of the thermistor the fan speed decreased. When I placed my finger on the thermistor, the fan speed increased due to the heat from my finger.