"average forward current" formula

Discussion in 'General Electronics Chat' started by Richard Lim, Oct 26, 2010.

  1. Richard Lim

    Thread Starter New Member

    Oct 25, 2010
    Looking for some formula to calculate "average forward current" for thyristors.
    Most thyristors spec are in "average forward current" but I cannot find any formulae for this.

    Only 1 reference I found so far in a handbook as it is dependent on conduction angle.
    Assuming I want to conduct for full 180 deg, what would be the "average forward current"? Say 100Arms on 50Hz sine wave.

    Is it the area under the sine?
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    The average of a half wave sinusoidal current = Imax/∏

    So If Imax=100A


    If Irms=100A then Imax=141.4A

    So Iaverage=141.4/3.1415926=45A

    In general Iav(of a simple half sine)=0.4502*Irms
    Last edited: Oct 27, 2010