Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

PC power consumption

  1. Jan 12, 2009 #1
    can anyone tell me my quote is feasible?

    Electronic devices requires 1 to 12v approx to function.
    Indian Electricity board supplies us 230v for domestic & official appliances; so additionally we need an AC adapter to convert into DC (a sort of stepping down the power) . we cannot ask government to supply 12v dedicated line for electronic devices (it's because of transmission loss & various technological factors)
    Rather, we can provide dedicated line from Intranet UPS that suites our requirement.

    We have a power distribution unit in our PC called SMPS (Switched Mode Power Supply)

    HTSL UPS --> 230V --> SMPS --> (5V, 2V, 6V, 12V… etc)

    SMPS takes 230V input & produces various lines of 6v, 2v, 5v, etc as per the requirement of internal components like motherboard, CPU, cooling fan, dos speakers, power led’s… etc.
    My solution starts here. We can supply 20v or the maximum output of SMPS from our local UPS. SMPS has to be modified so that it can take 20V input and produces the same output as it does with 230V

    HTSL UPS --> 20V --> Modified SMPS --> (5V, 2V, 6V, 12V… etc)

    This is for normal PC’s. When we think of laptops, no concept of SMPS, it has a battery, it can supply DC current of required voltages, To charge the battery, we have an adapter that takes, Input: 100-240V 1.3A(1,3 A) 50-60Hz & produces Output: 19.5V(19,5V) 4,7A(4,7 A).
    So, we can use our 20v output line from UPS directly to charge our laptop batteries without having an adapter.
    If we succeeds in this approach, we can save energy and it would be the optimal solution for future requirements.

    Vivek Ananda Raj
  2. jcsd
  3. Jan 12, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    You can distribute DC direct from the UPS to the computer, this is common in large data centers and especially telecoms - a couple of problems.
    You can't use a SMPS anymore, they need AC, so if you distribute a single DC supply (48V is normal) you need expensive DC-DC converters at each machine to generate +12V, +-5V. Alternatively you need complex wiring to distribute different DC voltages and keep their grounds correct.
    To run a lot of machines you need very heavy cables (DC needs heavier wires at the same current than AC), a 480W PSU replacement needs 20A at 12V for each PC.
    It's also difficult to switch high current DC.
    The SMPS is actually very efficient.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook