Suppose we have a pule with duty cycle 50% that means it will give half of voltage that we apply.Īrduino Temperature Controlled Fan Circuit DiagramĬonnections of this temperature controlled fan circuit is very simple, here a liquid crystal display is used for displaying temperature and Fan speed Status. The main game of PWM is digital pulse with some duty cycle and this duty cycle is responsible for controlling the speed or voltage. (To understand more about PWM, check this circuit: 1 Watt LED Dimmer) This concept is used in the project to control the voltage using PWM.
To understand it more simply, if you are applying 5 volt for driving a motor then motor will moving with some speed, now if we reduces applied voltage by 2 means we apply 3 volts to motor then motor speed also decreases.
What is PWM? PWM is a technique by using we can control the voltage or power. Then transistor creates a voltage according to the PWM input.įan speed and PWM values and duty cycles values are showing in given table We have created PWM at pwm pin of arduino and applied it at base terminal of the transistor. Here we have only used this DHT sensor for sensing temperature, and then programmed our arduino according to the requirements. Here in this project, we have used a sensor module namely DHT11 that already has discuss our previous project namely “ Humidity and Temperature Measurement using Arduino”. And last part of system shows humidity and temperature on LCD and Fan driver. The second section reads the dht11 sensor module’s output and extracts temperature value into a suitable number in Celsiu s scale and control the fan speed by using PWM. One senses the temperature by using humidity and temperature sensor namely DHT11.
Arduino Fan Speed Control using Temperature Sesnor