Arduino Pwm Fan Controller

Getting temperature values from a digital or analog temperature sensor on an arduino is fairly simple.

Arduino pwm fan controller.

The system works by an application running on the pc checking the cpu temperature and checking whether to speed up or slow down the fans. The arduino throttles the fans using pid logic and drives them through pwm. Design schematic diagram is shown next. I had 5 laying around and thought mine as well give it a shot.

The temperature and fan speed are reported through a 8 digit 7 segment display fitted on a rack mounted aluminium bar. It is efficient because the pass transistor is used as a switch. Many projects that use a temp sensor but never the most simple thing. In the above wave forms you can see that the frequency is same but on time and off time are different two applications of pwm control using arduino is shown here.

Pwm waves with various duty cycle are shown in the figure below. Temperature based fan speed control monitoring with arduino. An inexpensive single small pass transistor like 2n222 or bd139 can be used here. There is a jumper for switching the power supply from arduino or the 12v input.

I have been wondering about this project and how to control my 4 pin pwm fans. On the pcb there is a 5 12v input for the fan supply. The frequency values can be adjusted between 125 hz 8 mhz as well as a variable duty cycle. Beginner full instructions provided 24 154.

The ultimate project is to control the fan based on temperature. A low frequency pulse width modulation pwm signal whose duty cycle is varied to adjust the fan s speed is used. As long as the cooling is on the red led is on when not cooling the green led is on. The blue led seen on the prototype board is just for verifying correct circuit.

So after that no electricity flows through it turning the fan off. Pwm fan controller sketch can be downloaded here. The pc communicates with the arduino via the serial port. For this reason i used arduinos d6 pin pwm.

How to connect it. The system uses a temperature sensor to control four fans that are driven by an arduino controller. Control the speed of the fan. 4 wired fan control pwm control a pwm fan with arduino.

The pwm controller accepts the control signal and adjusts the duty cycle of the pwm signal according to the requirements. I simply want to control a 4 wired fan or maybe several with an arduino board. It then becomes a matter of telling the fan pwm to raise or lower the speed based on the temperature.