Fan behavior

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Danishblunt, Nov 12, 2017.

  1. Danishblunt

    Danishblunt Notebook Deity

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    So I was wondering, if I would connect lets say 3 fans on 1 fan header, all being 12V but having different amps, what would happen?

    Lets say:
    Fan 1 is 12v 0.2A
    Fan 2 is 12v 0.4A
    Fan 3 is 12v 0.5A

    Note that these fans are 3 wires fans, meaning they got ground, power and the thing that I'm not aware of. What exacly would happen then? I'm really confused about the last wire.
     
  2. Arrrrbol

    Arrrrbol Notebook Consultant

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    One of the wires is for sensing the fan speed I think.

    That is an interesting question though. Since the splitter is a parallel circuit the current is shared between the cables. Its possible fan 1 will run faster than it should and 2 and 3 will run slower. My knowledge of electronics is limited so someone please correct me, but I think the current does not affect the speed of the fan explicitly but the torque of the motor which would help it overcome the resistance of the air at high RPM. Im not sure weather the fans will try to draw over 1A from the header or weather the motherboard will limit the amperage to 1A and give the fans a lower current. If i were building a system though i'd use 3 identical fans on one header to make sure the RPM is the same.
     
  3. Danishblunt

    Danishblunt Notebook Deity

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    That's exacly what I'm wondering. Just ignore the 1AMP limit for now, I could have written 0.1A, 0.2A and 0.3A instead, I'm just curious as to what would happen with the lower and higher amp fans.
     
    Arrrrbol likes this.
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