water pump

Discussion in 'General Electronics Chat' started by teratron, Sep 24, 2008.

  1. teratron

    Thread Starter New Member

    Sep 22, 2008
    6
    0
    I bought a water pump from Harbor Freight Tools, item # 94639- 100watts., that works on 12vDC, primarily to be used in a boat, but I want to use it at home to pump water. I need to buy a power supply with 120vAC/12vDC. I need to know how many amperes should be the power supply to power the pump. You can check the pum spec. at www.harborfreight.com
     
  2. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    Hey,

    Water Pump
    P = 100W
    V = 12V
    I = P/V
    = 8.333A

    For the power supply, you should be able to specify a 100W supply at 12V. Supplies are commonly spec'd in power, rather than current and voltage.

    @120V, you will draw 100/120A, 0.833A

    Steve
     
  3. triggernum5

    Active Member

    May 4, 2008
    216
    0
    A PC psu should do the trick even.. The old AT psu I have here says its rated at up to 9A @ 12V.. Most modern ones are bigger.. You can jumper an ATX psu on by shorting the green wire going to the MB connector to gnd..
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I have an old Compaq 250W ATX form factor supply set up as a bench supply.
    The +12V is limited to 8A, so it would not be enough to run your pump.
    You will need to check the supply you're considering for such a conversion to ensure that it will supply enough current.

    Marlin P. Jones has a supply that will work; it's about $33.
    http://www.mpja.com/products.asp?dept=465&main=1
     
    Last edited: Sep 24, 2008
  5. vetterick

    Active Member

    Aug 11, 2008
    35
    0
    You might just buy yourself a 12V automotive battery charger, just get one 10A or better.
     
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