about RMS value

Discussion in 'General Electronics Chat' started by moh_alluzi, Mar 4, 2010.

  1. moh_alluzi

    Thread Starter New Member

    Mar 1, 2010
    hello ,
    i am mechanical engineer please i just want to ask about the RMS value why i use it and when what is the benifit of use the whole things please if u have an answer
    thank u all
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    We use the RMS value of AC electricity so the power calculations are the same as those for DC power.
  3. Mike33

    AAC Fanatic!

    Feb 4, 2005
    RMS (root-mean-square) is the AVERAGE current flowing in a circuit. As you know, AC is by definition alternating, so the best we can get to a 'real number' for it is the RMS average. It's a "power average", too....

    The true AC level (peak) is 1.414 times the RMS value. RMS = .707*peak.
    >>>At the RMS value, the current will do as much WORK as the same level of DC voltage<<<. Hence the term 'power average'.

    An example is 120VAC, RMS (U.S. line voltage)...its peak is 170VAC or so. But the average 120V will do as much work as 120 volts DC.
    You get used to using it after a while :eek:)
  4. bertus


    Apr 5, 2008