Wasted power

Discussion in 'General Electronics Chat' started by mrscrewdriver, Mar 2, 2011.

  1. mrscrewdriver

    Thread Starter New Member

    Dec 2, 2007
    :confused:Hi there i have connect 3 lamps in parallel with PC Power supply's +12 output. I have 2 watt meter clamp type. I both measure DC part and AC part at the same time here's the results:

    DC Part

    E(V) 11.4Volts
    I(A) 5.25Amps
    P(W) 60Watts

    AC Part

    E(V) 200V
    I(A) 0.47A
    RealPower(W) 72Watts
    ApparentPower(VA) 94VA
    ReactivePower(VAR) 60VAR
    PowerFactor(%) 0.77

    so above the results the wasted power is 16.56W is it right?

    and efficiency= dc output/ac in=0.83 is it right?

    i only loaded just +12V output the other rails unloaded
    sorry my bad English thank you very much
  2. kubeek


    Sep 20, 2005
    I would say it is 72-60=12W loss. Usually electricity meters (like for a house) measure real power, not apparent. Efficiency is 60/72=0.83.