Page 37 - Electrician - TT (Volume 2)
P. 37

ELECTRICIAN - CITS




           Calculation of Ripple : While designing a filter circuit the following methods can be used to calculate theoretically
           the ripple voltage in the output of the filter circuit.
           Method 1
           Knowing the required load current, IL, for a given value of frequency f and capacitance C, the peak-to-peak ripple
           voltage can be found using the formula,




           Where
           V r(p-p)    = peak-to-peak ripple voltage in volts
           i  = required Dc load current, in Amps
            L
           F  = ripple frequency, in Hz
            r
           C  = capacitance in Farads


               Fig 9









































           Fixing the permissible Vr(p-p) and knowing f and IL the required value for C can also be found using this formula
           Method 2
           Another method of expressing the ripple  in the output DC is by ripple factor r defined as,




           where,
           r = ripple factor (dimension less)
           V r (rms)  = rms value for ripple voltages.
           V  is the measured dc voltage at the output.
            dc



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                                    CITS : Power - Electrician & Wireman - Lesson 60-69
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