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Ban low power factor switch-mode power supplies?

Discussion in 'Electrical Engineering' started by ITSME.ULTIMATE, Dec 6, 2005.

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  1. It may not have been 15 years ago, but computers are rather significant
    power users.

    Modern PCs are gaining in processing power as well as electrical
    consumption. It isn't unusual for today's high performance PCs to draw
    250-300W of power in its idle state and 400-500W with the CPU and video
    card fully loaded.

    Computer power supplies with a power output in the neighborhood of half
    a kilowatt is not uncommon and most are rated for a minimum of 300W
    output. The average computer power supply is very high in THD and has a
    power factor of 0.6 to 0.7 and an efficiency rating of around 75%. With
    300W power consumption, each computer represents 430-500VA of highly
    harmonic load.

    I'm guessing a university and such would have around 1,000 computers
    through their campus labs which would create around 400 to 500kVA of low
    power factor load that power factor correction capacitors can not touch.

    Computers in homes don't produce as much of concentrated high harmonic
    loads, but rectified input draw is quite a significant part of load on
    the power distribution facilities.

    There is already a power factor regulation for fluorescent lights and as
    a result, many electronic types of ballast have a power factor rating as
    high as 0.95-0.99.

    Why can't they put a ban on computer power supplies and other high VA
    non-sinusoidal appliances such as a big screen TV with an absolutely
    lousy power factor and disgustingly high harmonics?
  2. Calm down. Go here:

    The EPA and California Energy Commission are already on the job.

    Charles Perry P.E.
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