computer power supply cooling fan?

Discussion in 'Homework Help' started by terrakota, Feb 8, 2005.

  1. terrakota

    Thread Starter Well-Known Member

    Feb 8, 2005
    67
    1
    Hi,
    I'm new to electronics, i have some computer power supply cooling fans and Im trying to make some experiments but i have some questions about it:

    those cooling fans are AC or DC? wich voltage they need to work? is there a simple way to put then to work?(with a simple battery connection and on/off switch)

    in the back side of the power supply plate says "temperature sensor power supply"

    thanks for any help and please excuse my poor english
     
  2. dragan733

    Senior Member

    Dec 12, 2004
    152
    0
    This cooling fan, has three wires? If it so, then yellow wire connect to +12V and black wire to "-" of the battery, and the cooling fan will work permanently untill there exists voltage 12V.
     
  3. terrakota

    Thread Starter Well-Known Member

    Feb 8, 2005
    67
    1
    nope it haves only 2 wires, black and red...

    any idea?

    thanks for reply
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    In that case, apply +12 to the red wire (black is common), and the fan should go. If not, it may have failed and need to be replaced.
     
  5. terrakota

    Thread Starter Well-Known Member

    Feb 8, 2005
    67
    1
    ok, but those fans use DC not AC?

    thanks for help
     
  6. dragan733

    Senior Member

    Dec 12, 2004
    152
    0
    But, "beenthere" speaks for +12VDC. At least, it needs a knowledge of Electronics. :(
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    These fan motors are called brushless DC motors. As we all know, a "real" DC motor need brushes to pass current through the armature and provide for the field reversals that keep the motor rotating. A brushless motor has a small circuit board under the fan rotor that generates a psuedo-AC waveform so the fan can run like an AC motor, with induced fields in the armature.
     
  8. terrakota

    Thread Starter Well-Known Member

    Feb 8, 2005
    67
    1
    thanks a lot for your help
     
  9. torpedopudding

    Member

    Feb 6, 2005
    28
    0
    OK, dudes (dudettes) if they have black and red then they are DC but I did not see anyone confirming that the voltage is 12V. I think 12V IS the most common but there are fans out there rated 5V, 24V, and 48V. Putting 12V on a 5V fan is likely to destroy it.

    Red will be positive and black is negative. Make this an ALWAYS rule!

    Can you read any information on the fan label?

    Otherwise try 5V first. A 12V fan should start to run with 5V but not a lot of power.

    Most DC fans are brushless, but keep in mind that a brushless fan is much better than a fanless brush. Likewise for drill-less cords and phoneless cords. :)
     
  10. terrakota

    Thread Starter Well-Known Member

    Feb 8, 2005
    67
    1
    ok thanks for help, and no the dont have any clue i just can tell you is a fan i extract from an old pc power supply
     
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