Electronics PC Relay board question...

Discussion in 'Modding' started by Stealthrt, 10 Feb 2003.

  1. Stealthrt

    Stealthrt What's a Dremel?

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    Hi all, i have a question about my PC Relay i just bought.... There is 3 connections being made to each relay on the board. They are labled as follows:

    NC C NO
    _ _ _

    Here is a picture of what i am talking about...
    [​IMG]
    [​IMG]
    [​IMG]

    In the picture above the 3 connections are above the relay (very top behind the relay itself)

    How do i wire up a computer fan (RED & BLACK wires) to it? What goes where and why is there 3 inputs when i only have 2 for the fan?

    Thanks for your time!
    David:D
     
    Stealthrt, 10 Feb 2003
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  2. ZapWizard

    ZapWizard Enter the Mod Matrix

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    NC=Normaly Closed Meaning there will be a connection from COMMON to this Pin when the relay is OFF, and disconnected when the relay is powered ON

    C=COMMON this is the, well... common pin. It is switched between NC and NO (OFF and ON)

    NO=Normaly Open meaning there will be NO connection to the Common Pin when the relay is OFF. And connected when the relay is powered ON

    So:

    +12volts.....Relay(NO).....Common.....Fan+.....Fan-...Ground

    When the relay is turned on the Fan gets power.
     
    ZapWizard, 11 Feb 2003
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  3. Stealthrt

    Stealthrt What's a Dremel?

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    Zapwizard,
    Thanks for the reply.....

    so i hook it up like this?

    RED wire to the NO
    BLACK wire to the C

    ???

    Thanks,
    David
     
    Stealthrt, 11 Feb 2003
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  4. cpemma

    cpemma Ecky thump

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    No, 12v (yellow) to common, Red fan wire to NO, Black fan wire to ground (or as Zap showed in his post, 12v to NO, fan red to common...same circuit)
     
    cpemma, 11 Feb 2003
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  5. Stealthrt

    Stealthrt What's a Dremel?

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    ah, thanks, it works now.

    Doesnt really make any since that it has 12v power already on the board and u still have to provide 12v to each relay.... just doesnt really make since in the design... but anyways.


    Thanks again for your help cpemma,
    David
     
    Stealthrt, 11 Feb 2003
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  6. cpemma

    cpemma Ecky thump

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    The relay coil runs off a 12v supply, but the relay switch can be connected to any voltage you need switching. By coincidence, they're both 12v in this case. ;)
     
    cpemma, 11 Feb 2003
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