[Low cost] Welding fume fan/cooling fan

 
 
Features:
 
        Violent fan, 50W power, side length 9CM, thickness 3.8CM, speed 8000 rpm, large air volume (proportional to the noise), PWM speed adjustable. Can be used to absorb welding fumes and dissipate heat from laptops. Remove the filter cotton and use it to blow air, which is very cool.
 
 
Materials:
 


50W violent fan 9CM 18.3 yuan
filter cotton 1M*1M*3MM 10 yuan
simple two-way PWM module 4.6 yuan
2.54cm pin header 0.01 yuan
fan wiring PCB board Free
Jialichuang paper box Free
wallpaper knife, scissors, double-sided tape


 
 
Requirements:
 
      12V power supply, current supply of about 4.5A (at full power), it is recommended to use an ATX power adapter board. In this project, the 12V power supply and power issues have been solved.
 
 
Note:
 
        The input voltage of the PWM is drawn from the fan terminal board (the two ears on the PCB), and the high-level voltage of the PWM can be converted by changing the input voltage. However, in this project, you do not need to connect the PWM input voltage and use the module's own voltage, which is 5V by default.
 
        The switch in the wiring board has two gears, downward to ground, which is the lowest speed (idle speed), and upward to connect to the PWM wave. By setting the PWM module to adjust the speed (the higher the duty cycle, the higher the speed), the PWM module adjusts the frequency to 25KHZ
 
        uses Dupont wire to connect to the 12V power supply. Considering the current problem, 3 wires of 12V and GND are used for shunting. Both PWM channels are led to the wiring board and can be used for other purposes.
 
        Since the PWM module is relatively cheap, setting the duty cycle is a bit troublesome, and speed adjustment is not very convenient. It can only take effect after it is set.
 
        Depending on the purpose, just open holes on the back or side of the carton for ventilation and add filter cotton. (You can tear it off when not in use, it is easy to tear with double-sided tape)
 
        Red wire 12V, black wire GND, blue wire PWM speed control, yellow wire speed monitoring (not required for this project)