Calculating Average Current

The I_ave  can be calculated in one of two ways

(a) We might determine the value of V_ave and then use Ohm's law as follows

                                                  I_ave = V_ave/R_L

(b)   We might convert I_pk to average from utilizing same fundamental equations, that

        We utilized to convert V_pk to V_ave. The current form of these equations is

                                                 I_ave = I_pk/π

                                    And

                                                 I_ave = 0.318(I_pk)

EXAMPLE :     Calculate the dc load current for the rectifier indicated in diagram.

SOLUTION:

            The transformer has 24 V_ac rating. Therefore, the peak secondary voltage is determine as

                                                V₂(pk) = 24Vac/0.707

                                                            V₂(pk)  = 33.9 Vpk

                                    The peak load voltage is now determined as

                                                V_L(pk) = V₂(pk) - 0.7

                                                            V_L(pk) = 33.2 V_pk

                                                  I_L(pk)= V_L(pk)/R_L

                                                                       = 33.2/ 20k

                                                             I_L(pk)= 1.66mApk       

                                                    I_ave = I_pk/ π= 1.66m/π

                                                    I_ave = 529.13 micro A