The main objective of this paper is to design a circuit that can control the speed of a fan based on the ambient temperature. The fan is used for preventing the heat problems faced while using high graphics in a laptop or PC. The speed of the fan is varied based on the pulses that the timer sends out and the concept of pulse width modulation is used. This provides a simple and inexpensive way to protect systems like a computer from overheating. The existing external PC cooling fans have a higher energy consumption than the proposed model. This model is temperature controlled and the motor is powered on and off based on the pulsed output from the Pulse Width Modulator (PWM) generator circuit which invariably depends on the temperature. Hence the model provides cooling based on the need rather than continuously.
