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Electrical question

Hello,
i have 2 24 volt fans and a 12 volt power supply. is there a way too wire the fans too see 24 volts with a 12 volt power supply or would this effectivley reduce the output?
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  1. There is a way but you could have problems with it.
    Read this http://www.afrotechmods.com/fanmod.htm
  2. Best answer
    How big are these 12 V fans? The -12V rail on a computer PSU has a very low current capacity, generally less than 1 amp so there really isn't much power available to work with.

    More complicated but more reliable way to do it would be to use something called a "Voltage Doubler", it uses 2 capacitors and 2 diodes to approximately double the voltage on its output, you would need to make sure you use components of the appropriate rating in it which will depend on the current draw of the fans.

    http://www.coolcircuit.com/circuit/voltage/


    Edit: Power electronics fail! Forgot it needed an AC input signal :(
  3. Best answer selected by icycles.
  4. hunter315 said:
    How big are these 12 V fans? The -12V rail on a computer PSU has a very low current capacity, generally less than 1 amp so there really isn't much power available to work with.

    More complicated but more reliable way to do it would be to use something called a "Voltage Doubler", it uses 2 capacitors and 2 diodes to approximately double the voltage on its output, you would need to make sure you use components of the appropriate rating in it which will depend on the current draw of the fans.
    http://www.coolcircuit.com/circuit/voltage/vd.GIF
    http://www.coolcircuit.com/circuit/voltage/


    hunter315, i followed the link, is one voltage double better than the other? the fans are 4" or less and not being used on a computer.
  5. Somehow manager to forget all my power electronics in like three months sorry. That voltage doubler is for an AC in and provides a DC out, which explains why when i first wrote that i was trying to figure out why it didn't need a boost converter to increase the voltage. That won't actually work since it is a DC input signal sorry.

    There is an alternative option though, if we ignore trying to do it from a 12 V line on an ATX PSU and instead opt for a $15 PSU built for the purpose!
    http://www.circuitspecialists.com/24-volt-1-amp-power-supply.html

    It isn't exactly the safest one if you are going to have it in an exposed area due to how the connectors are, but it will get the job done. I would put it in a secured area where things won't fall on it but it will have some room to breath.
  6. hunter315, when i followed the link it looks like the unit is ac in and out. maybe i just don't understand what i am reading but i do need 12vdc in and 24vdc out.
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