Temperature Controlled Dc Fan Circuit

My temperature controlled fan circuit has a liquid crystal display connected to the arduino to display the temperature in celsius and fan speed 50 255 pwm this controls the duty cycle of the fan which then controls the fan speed.

Temperature controlled dc fan circuit. The temperature sensor output is read by the arduino and the software establishes the desired fan speed for a. This is an updated version of the old circuit designed by d mohankumar that didn t function at all. The circuit mainly consists of atmega8 microcontroller temperature sensor dc motor driver ic. When the temperature increases the base current of q1 bc 547 increases which in turn decreases the collector voltage of the same transistor.

In this circuit pin 3 non inverting terminal of op amp 741 is connected with the potentiometer and pin 2 inverting terminal is connected in between of r2 and rt1 thermistor which is making a voltage divider circuit. Middle one is output and the other two pins are. Working of temperature controlled dc fan using thermistor. Circuit components arduino uno.

Pwm is a technique by using which we can control voltage. Simplest 12v cooling fan controller with temperature status using thermistor temperature sensor ntc mf52 103 thermistor nec d882 tp 120 and tl431 transist. It is accomplished by the data communications between arduino lcd dht11 sensor module and dc fan that is controlled by using pwm. This thermistor variable resistance value based on the temperature when the temperature rises then thermistor resistance gets decrease and for temperature decrease then thermistor resistance gets increase.

The second temperature controlled dc fan circuit project discussed below automatically senses the ambient temperature and adjusts the fan motor speed to keep the surrounding temperature under control. I had to remove the leds and use different values for r1 and r2 and now it works as you can see in the video below. Here is circuit diagram of automatic temperature controlled dc fan controller. Temperature sensor is connected to the input of the adc pin i e.

Temperature sensor has three input pins vcc ground. Adc0 pin of the microcontroller. It works on the principle of thermistor. This automatic processing is done through an arduino and a temperature sensor ic lm35.

Temperature controlled dc fan circuit design. Simple temperature controlled dc fan circuit is designed with negative temperature co efficient thermistor and an operational amplifier. Here is a simple circuit based on two transistors that can be used to control the speed of a 12 v dc fan depending on the temperature a thermistor r1 is used to sense the temperature.