Automatic fan speed regulator automatically regulates the speed of the fan according to the temperature inside the room. Due to sudden changes in atmosphere because of pollution, we feel hot and after some time we feel cold. And we have to regulate the speed of fan. Hence to solve this problem we have described this simple circuit. Automatic fan speed regulator automatically regulates the speed of the fan according to the temperature inside the room. Due to sudden changes in atmosphere because of pollution, we feel hot and after some time we feel cold. And we have to regulate the speed of fan. Hence to solve this problem we have described this simple circuit. Continue reading to find out how the circuit can be assembled and how it works.